25 research outputs found
Fixed and volatile constituents oF genus Croton plants: C. adenoCalyx Baill -euphorBiaceae
aBstract This work describes the phytochemical analysis of Croton adenocalyx Baill (Euphorbiaceae), a plant that is representative of the species from Ceará State (Brazil). The GC-MS analysis of the essential oil, obtained by hydrodistillation of the leaves from C. adenocalyx, allowed the identification of eleven volatile constituents; the main components were identified as α-pinene (32.63%); bicyclogermacrene (13.96%); trans-caryophyllene (10.23%); germacrene D (10.14%); β-pinene (10.11%) and β-elemene (8.31%). The chromatographic purification of the ethanolic extract from the trunk bark, allowed the isolation and identification of the 6-methoxy-7-hydroxycoumarin (1) and 3´,5-dihydroxy-3,4´,7-trimethoxyflavone (2). Keywords: Euphorbiaceae, Croton adenocalyx, Essential oil, GC-MS, Flavonoid, Coumarin. resumen Este trabajo describe el análisis fitoquímico de Croton adenocalyx Baill (Euphorbiaceae), una planta representativa de las especies del Estado de Ceará-Brasil. El análisis por CG-EM del aceite esencial, obtenido por hidrodestilación de las hojas de C. adenocalyx Baill, permitió la identificación de diez constituyentes volátiles. Los componentes mayoritarios fueron identificados como α-pineno (32.63%), biciclogermacreno (13.96%), trans-cariofileno (10.23%), germacreno D (10.14%), β-pineno (10.11%) y β-elemeno (8.31%). La purificación cromatográfica del extracto etanólico de la corteza del tronco, permitió aislar e identificar la coumarina 6-metoxi-7-hidroxicumarina (1) y el 3´,5-dihidroxi-3,4´,7-trimetoxiflavona (2)
Spelling pronunciation and visual preview both facilitate learning to spell irregular word
Spelling pronunciations are hypothesized to be helpful in building up relatively stable phonologically underpinned orthographic representations, particularly for learning words with irregular phoneme-grapheme correspondences. In a four-week computer-based training, the efficacy of spelling pronunciations and previewing the spelling patterns on learning to spell loan words in Dutch, originating from French and English, was examined in skilled and less skilled spellers with varying ages. Reading skills were taken into account. Overall, compared to normal pronunciation, spelling pronunciation facilitated the learning of the correct spelling of irregular words, but it appeared to be no more effective than previewing. Differences between training conditions appeared to fade with older spellers. Less skilled young spellers seemed to profit more from visual examination of the word as compared to practice with spelling pronunciations. The findings appear to indicate that spelling pronunciation and allowing a preview can both be effective ways to learn correct spellings of orthographically unpredictable words, irrespective of age or spelling ability. Copyright © 2006 by The International Dyslexia Association®
Reduction of late stillbirth with the introduction of fetal movement information and guidelines – a clinical quality improvement
We have performed a full cross-validation of this clinical Femina data collection against the routinely collected data of the Medical Birth Registry of Norway to validate the estimates of reduced mortality in the total population. The original estimate of fewer deaths during the intervention with OR 0.7 remains virtually unchanged for the original data collection
The Effects of Video Feedback Coaching for Teachers on Scientific Knowledge of Primary Students
Attention Deficit Hyperactivity Disorder Symptoms and Low Educational Achievement: Evidence Supporting A Causal Hypothesis
Toxicological, chemopreventive, and cytotoxic potentialities of rare vegetal species and supporting findings for the Brazilian Unified Health System (SUS)
Caatinga flora which are found in a poor Brazilian region contain a substantial number of endemic taxa with biomedical and social importance for regional communities. This study examined the antioxidant and cytotoxic potential of 35 samples (extracts/fractions) from 12 Caatinga species and determined the antiproliferative and genotoxic action of dichloromethane fraction from Mimosa caesalpiniifolia stem bark (DC-Mca) on human and vegetal cells. Samples were assessed for chemopreventive ability, toxic effects on Artemia salina shrimp as well as cytotoxicity on tumor cell lines and erythrocytes. DC-Mca was also tested with respect to antiproliferative and genotoxic effects upon normal leukocytes and meristematic cells from A. cepa roots. Some extracts reduced free radical levels >95% and 7 samples exhibited a lethal concentration (LC) 50 < 100 µg/ml upon Artemia salina larvae. Eight samples displayed in vitro antitumor effects and three produced hemolysis. Data also demonstrated the pharmacological significance of bioactive extracts from Brazilian semi-arid region. There was no significant relationship between antioxidant, toxic, and antiproliferative activities, and that these properties were dependent upon the extractant. DC-Mca contained betulinic acid as main compound (approximately 70%), which showed higher (1) cytotoxic activity on cancer cell lines and dividing leukocytes, (2) reduced mitotic index of Allium cepa roots, and (3) induced cell cycle arrest and chromosomal bridges, thereby providing native promising sources for phytotherapy development. Abbreviations: ABTS: 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid); AcOH: ethyl acetate; ANOVA: analysis of variance; SUS: Brazilian Unified Health System; DC-Mca: dichloromethane fraction from Mimosa caesalpiniifolia stem bark; DMSO: dimethylsulfoxide; DPPH: 1,1-diphenyl-2-picrylhydrazyl; EC50: effective concentration 50%; EtOAc: ethyl acetate; FDA: Food and Drug Administration; GC-Qms: gas chromatograph quadrupole mass spectrometer; GI: genotoxic index; HCT-116: colon carcinoma line; HL-60: promyelocytic leukemia line; HPLC: high-performance liquid chromatography; HRAPCIMS: high resolution atmospheric pressure chemical ionization mass spectrum; IC50: inhibitory concentration 50%; LC50: lethal concentration 50%; MeOH = methyl alcohol; MI: mitotic index; MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide; MutI: mutagenic index; OVCAR-8 = ovarian carcinoma line; PBMC: peripheral blood mononuclear cells; RPMI-1640: Roswell Park Memorial Institute medium; SF-295: glioblastoma line; TEAC: trolox equivalent antioxidant capacity; TLC: thin-layer chromatography; Trolox: 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid
The Role of Linguistic Diversity in the Prediction of Early Reading Comprehension: A Quantile Regression Approach
Variability of computational fluid dynamics solutions for pressure and flow in a giant aneurysm: the ASME 2012 Summer Bioengineering Conference CFD Challenge
A comprehensive study on different modelling approaches to predict platelet deposition rates in a perfusion chamber
Benefits of computer-presented speed training for poor readers
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56702.pdf (publisher's version ) (Closed access)The effects of computer-presented automatization exercises in a group of 14 poor readers were assessed in comparison to a matched control group of 14 poor readers that received computer-presented exercises aimed at the use of context for word identification and comprehension. Training took place three sessions a week for 15 minutes per session and lasted about two months in each group. Results showed that the automatization or “speed” group progressed more than the context group in word and text reading efficiency, and the effect transferred to more complex word types than the CVC word type that was presented in the exercises. Both groups progressed to the same extent in accuracy, but the speed group made more progress in speed. No effects were found for reading comprehension. The findings make clear that computer-supported automatization exercises can be effective in reducing reading problems of poor readers in a short period of time. Implications for practice are discussed