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Registros recuperados: 49 | |
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Malta, Marcelo Ribeiro; EPAMIG; Chagas, Sílvio Júlio de Rezende; EPAMIG. |
O presente trabalho teve como objetivo avaliar os teores de trigonelina, ácidos clorogênicos (5-ACQ) e cafeína em grãos de diferentes cultivares de cafeeiro (Coffea arabica L.). As cultivares avaliadas foram coletadas na Fazenda Experimental da Epamig em Lavras, Estado de Minas Gerais, no ano agrícola de 2005/2006. O delineamento experimental utilizado foi um inteiramente casualizado constando de oito cultivares de café com três repetições. Foram avaliadas as cultivares: Oeiras MG 6851, Acaiá Cerrado MG 1474, Catuaí Vermelho IAC 99, Rubi MG 1192, Topázio MG 1190, Mundo Novo IAC 379/19, Catucaí Amarelo 2 SL e Catuaí Amarelo IAC 62. Após a colheita dos cafés por derriça manual no pano, estes foram lavados e submetidos ao processo de descascamento e... |
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Palavras-chave: 5.01.03.04-0 Produção de Mudas Coffea arabic; Melhoramento; Composição química; Ácido clorogênico; Cafeína; Trigonelina. Coffea Arabica; Breeding; Chemical composition; Chlorogenic acids; Caffeine; Trigonelline. |
Ano: 2009 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/6629 |
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Reis,A.M.S.; Oliveira,K.P.; Paula,I.H.F.; Silva,A.P.; Tarragô,J.F.; Ocarino,N.M.; Serakides,R.. |
ABSTRACT The aim of this study was to evaluate the effect of concentrations of caffeine on the viability, synthesis activity and gene expression in cultures of chondrocytes. Extracted articular cartilage from the femurs and tibias of 15 Wistar rats at three days old to isolate chondrocytes. Chondrocytes were cultured in chondrogenic medium (control) or supplemented with caffeine (0.5, 1.0, 2.0mM). Cell viability, alkaline phosphatase activity and collagen synthesis were assessed using colorimetric assays at 7, 14, 21 days. The chondrocyte cultures of all groups grown under coverslips were stained with hematoxylin-eosin to determine the percentage of cells/field and with PAS, safranin O, alcian blue to determine the percentage of matrix chondrogenic/field... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rats; Caffeine; Chondrocytes; Chondrogenesis. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352019000200509 |
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Del Campo,A.; Bracho,M.; Marcano,L.; Guíñez,J.; De la Torre,C.. |
This work evaluated the qualitative and quantitative cellular changes induced by treatment with 5-aminouracil (5-AU) and a combination of 5-AU and caffeine in plant cells in relation to DNA damage, repaired damage, and residual damage. As biological material, Allium cepa L. root tips were used, grown in filtered water, in darkness, with aeration at constant temperature of 25 °C ± 0.5. Cell populations were synchronized using 5 mM caffeine in order to study the effects of 5-AU and caffeine/5-AU combined treatment on the DNA content and their incidence in the entrance to mitosis. The results showed a delay in the G2 period due to induced DNA damage by the 5-AU and caffeine/5-AU combined treatment, shown by aberrant metaphases, anaphases and telophases. The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 5-aminouracil; G2 checkpoints; Caffeine. |
Ano: 2005 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452005000200003 |
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Marcelain,Katherine; de la Torre,Consuelo; González,Patricio; Pincheira,Juana. |
Checkpoint response to DNA damage involves the activation of DNA repair and G2 lengthening subpathways. The roles of nibrin (NBS1) and the ATM/ATR kinases in the G2 DNA damage checkpoint, evoked by endogenous and radio-induced DNA damage, were analyzed in control, A-T and NBS lymphoblast cell lines. Short-term responses to G2 treatments were evaluated by recording changes in the yield of chromosomal aberrations in the ensuing mitosis, due to G2 checkpoint adaptation, and also in the duration of G2 itself. The role of ATM/ATR in the G2 checkpoint pathway repairing chromosomal aberrations was unveiled by caffeine inhibition of both kinases in G2. In the control cell lines, nibrin and ATM cooperated to provide optimum G2 repair for endogenous DNA damage. In... |
Tipo: Journal article |
Palavras-chave: Ataxia-telangiectasia; ATM; ATR kinases; Caffeine; G2 checkpoint; Nibrin (Nbs1); Nijmegen breakage syndrome (NBS). |
Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000200007 |
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Benatti,Luciana Benjamim; Silvarolla,Maria Bernadete; Mazzafera,Paulo. |
We compared the biochemical characteristics of the beans of a naturally decaffeinated Arabica coffee (AC1) discovered in 2004 with those of the widely grown Brazilian Arabica cultivar "Mundo Novo" (MN). Although we observed differences during fruit development, the contents of amino acids, organic acids, chlorogenic acids, soluble sugars and trigonelline were similar in the ripe fruits of AC1 and MN. AC1 beans accumulated theobromine, and caffeine was almost entirely absent. Tests on the supply of [2-14C] adenine and enzymatic analysis of theobromine synthase and caffeine synthase in the endosperm of AC1 confirmed that, as in the leaves, caffeine synthesis is blocked during the methylation of theobromine to caffeine. The quality of the final coffee... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffea arabica; Caffeine; Decaffeination; Beverage quality. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052012000200001 |
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Bührer,Nilton E.. |
In this work the author puts in evidence a practical and at the same time rapid method for the determination of the cafein quantity in erva-mate, that may be utilized to perfection in food and industrial analyses or others that not demand scientific rigour. The author presents a description of the method and makes a comparison with the classical method of Grandval-Lajoux, showing that the differences between the one and the other are practically nil. In conclusion, the result of the three analyses of the same sample of erva-mate, made by the Grandval-Lajoux method are cited, show that the same differences appear as those shown between the rapid method suggested by the author and the classical method. In this case, the maximum difference was 0,06% and the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Caffeine; Erva-mate; Caffeine assay. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132001000500007 |
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Sartor,Rosana Mary; Mazzafera,Paulo. |
The low caffeine content in leaves of C. dewevrei (~ 0.5 mg/g) is due to a low biosynthesis associated with a fast degradation. On the other hand, high biosynthesis and low degradation confer a higher content (~ 8 mg/g) in leaves of C. arabica. In this work it was observed that cell cultures of C. dewevrei recovered the ability to synthesize caffeine almost in similar levels of C. arabica cultures. Tracer experiments with labelled carbon dioxide showed a significant accumulation of radioactivity in caffeine and metabolites, indicating an active biosynthesis. When the cultures were fed with labelled caffeine most of the radioactivity was recovered in caffeine, indicating that although active, degradation was not so efficient as in leaves, and therefore,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffee; Caffeine; Cell suspension culture; Methylxanthines. |
Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132000000100009 |
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Gomes,Júlia Ariana de Souza; Faria,Bruno Generoso; Silva,Viviam de Oliveira; Zangerônimo,Márcio Gilberto; Miranda,José Rafael; Lima,Adriene Ribeiro de; Pereira,Rosemary Gualberto Fonseca Alvarenga; Pereira,Luciano José. |
The objective of this study was to evaluate the influence of integral and decaffeinated coffee brews (Coffea arabica L and C. canephora Pierre) on the metabolic parameters of rats fed with hyperlipidemic diet. Thirty male Wistar rats (initial weight of 270 g ± 20 g) were used in the study, which were divided into six groups five each. The treatments were normal diet, hyperlipidemic diet, hyperlipidemic diet associated with integral coffee arabica or canephora brews (7.2 mL/kg/day) and hyperlipidemic diet associated to decaffeinated arabica, or canephora brews, using the same dosage. After 41 days, performance analyses were conducted.The rats were then euthanized and the carcasses were used for the analysis of dried ether extract and crude protein.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lipids; Adipocytes; Hyperlipidemia; Caffeine; Decaffeination. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132013000500015 |
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Ferreira,Paula; Soares,Geraldo Luiz Gonçalves; D'ávila,Sthefane; Bessa,Elisabeth Cristina de Almeida. |
Subulina octona is a terrestrial snail which serves as an intermediate host for the parasites. It is also an agricultural pest. The aim of this work was to assess, during 120 days, the effects of caffeine and thymol at 2.5 g/L and 5 g/L on the hatchability, survival after hatching, growth and reproduction of S. octona under the laboratory conditions. A total of 240 eggs, 240 juveniles aged 10-day-old, and 240 aged 30-day-old were tested. The results showed that thymol (at 2.5 g/L and 5 g/L) and caffeine (at 5 g/L) acted as ovicides. In the 10-day-old juveniles, caffeine at 5 g/L caused 25% mortality and at 2.5 g/L it caused 30% mortality. Thymol at 2.5 and 5 g/L caused 20 and 22.5% mortality, respectively. In the 30-day-old juveniles, caffeine at 5 g/L... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Caffeine; Thymol; Molluscicide; Subulina octona; Snail-terrestrial. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000400018 |
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Machado,Silmara Rodrigues; Parise,Edison Roberto; Carvalho,Luciana de. |
The potential role of coffee as a hepatoprotective substance for chronic liver diseases has been widely discussed. Our main aim was to evaluate the effect of coffee intake regarding clinical, biochemical tests and liver biopsy data in treatment naïve patients with chronic hepatitis C. One hundred and thirty-six patients with chronic hepatitis C, diagnosed through liver biopsy, or by means of clinical, ultrasound or endoscopic signs of cirrhosis, were assessed by determination of biochemical tests, metabolic and morphological alterations. Food frequency was scrutinized by using a structured questionnaire. Coffee intake represented more than 90% of the total daily caffeine, and the 75th percentile was 4-Brazilian coffee-cup/day (>255mL/day or >123mg... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffee; Caffeine; Hepatitis C; Fibrosis. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702014000200170 |
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Deslandes,A.C.; Veiga,H.; Cagy,M.; Piedade,R.; Pompeu,F.; Ribeiro,P.. |
Caffeine is the most consumed psychoactive substance in the world. The effects of caffeine have been studied using cognitive and motor measures, quantitative electroencephalography (qEEG) and event-related potentials. However, these methods are not usually employed in combination, a fact that impairs the interpretation of the results. The objective of the present study was to analyze changes in electrophysiological, cognitive and motor variables with the ingestion of caffeine, and to relate central to peripheral responses. For this purpose we recorded event-related potentials and eyes-closed, resting EEG, applied the Stroop test, and measured reaction time. Fifteen volunteers took caffeine (400 mg) or placebo in a randomized, crossover, double-blind... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Quantitative electroencephalography; P300; Caffeine; Cognitive and motor measures; Psychostimulants. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000700011 |
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Human skinned muscle fibers were used to investigate the effects of bovine serum albumin (BSA) on the tension/pCa relationship and on the functional properties of the Ca2+-release channel of the sarcoplasmic reticulum (SR). In both fast- and slow-type fibers, identified by their tension response to pSr 5.0, BSA (0.7-15 µM) had no effect on the Ca2+ affinity of the contractile proteins and elicited no tension per se in Ca2+-loaded fibers. In contrast, BSA (>1.0 µM) potentiated the caffeine-induced tension in Ca2+-loaded fibers, this effect being more intense in slow-type fibers. Thus, BSA reduced the threshold caffeine concentration required for eliciting detectable tension, and increased the amplitude, the rate of rise and the area under the curve... |
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Palavras-chave: Calcium-release channel; Sarcoplasmic reticulum; Human muscle fiber; Bovine serum albumin; Caffeine. |
Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000500017 |
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Denadai,B.S.; Denadai,M.L.D.R.. |
Controversy still exists concerning the potential ergogenic benefit of caffeine (CAF) for exercise performance. The purpose of this study was to compare the effects of CAF ingestion on endurance performance during exercise on a bicycle ergometer at two different intensities, i.e., approximately 10% below and 10% above the anaerobic threshold (AT). Eight untrained males, non-regular consumers of CAF, participated in this study. AT, defined as the intensity (watts) corresponding to a lactate concentration of 4 mM, was determined during an incremental exercise test from rest to exhaustion on an electrically braked cycle ergometer. On the basis of these measurements, the subjects were asked to cycle until exhaustion at two different intensities, i.e.,... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Caffeine; Anaerobic threshold; Endurance; Lactate; Perceived exertion. |
Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000400017 |
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Registros recuperados: 49 | |
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