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| Registros recuperados: 35 | |
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| Perseguini,N.M.; Takahashi,A.C.M.; Rebelatto,J.R.; Silva,E.; Borghi-Silva,A.; Porta,A.; Montano,N.; Catai,A.M.. |
| The objective of this study was to use linear and non-linear methods to investigate cardiac autonomic modulation in healthy elderly men and women in response to a postural change from the supine to the standing position. Fourteen men (66.1 ± 3.5 years) and 10 women (65.3 ± 3.3 years) were evaluated. Beat-to-beat heart rate was recorded in the supine and standing positions. Heart rate variability was studied by spectral analysis, including both low (LFnu-cardiac sympathetic modulation (CSM) indicator) and high (HFnu-cardiac vagal modulation (CVM) indicator) frequencies in normalized units as well as the low frequency/high frequency (LF/HF) ratio. Symbolic analysis was performed using the following indexes: 0V% (CSM indicator), 1V% (CSM and CVM indicators),... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Heart rate variability; Autonomic nervous system; Symbolic analysis; Spectral analysis; Elderly; Gender. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000100005 |
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| Vieira,T.M.M.; Oliveira,L.F.; Nadal,J.. |
| Even though frequency analysis of body sway is widely applied in clinical studies, the lack of standardized procedures concerning power spectrum estimation may provide unreliable descriptors. Stabilometric tests were applied to 35 subjects (20-51 years, 54-95 kg, 1.6-1.9 m) and the power spectral density function was estimated for the anterior-posterior center of pressure time series. The median frequency was compared between power spectra estimated according to signal partitioning, sampling rate, test duration, and detrending methods. The median frequency reliability for different test durations was assessed using the intraclass correlation coefficient. When increasing number of segments, shortening test duration or applying linear detrending, the median... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Center of pressure; Spectral analysis; Quiet standing; Estimators; Median frequency. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000700012 |
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| Huber,D.A.; Carmo,J.M. do; Castania,J.A.; Fazan Jr,R.; Salgado,H.C.. |
| Because it is not known where in the reflex arch, i.e., afference, central nervous system or efferences, hyperglycemia affects baroreflex function, the present study examined the effect of short-term (30 min) hyperglycemia on aortic depressor nerve function measured by a mean arterial pressure vs aortic depressor nerve activity curve, fitted by sigmoidal regression, or by cross-spectral analysis between mean arterial pressure and aortic depressor nerve activity. Anesthetized male Wistar rats received an intravenous bolus (0.25 mL) injection, followed by 30 min of infusion (1 mL/h) of 30% glucose (N = 14). Control groups received a bolus injection and infusion of 0.9% saline (N = 14), or 30% mannitol (N = 14). Glucose significantly increased both blood... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pressoreceptors; Hyperglycemia; Arterial pressure; Spectral analysis. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007001100017 |
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| Kunz,V.C.; Borges,E.N.; Coelho,R.C.; Gubolino,L.A.; Martins,L.E.B.; Silva,E.. |
| The objectives of this study were to evaluate and compare the use of linear and nonlinear methods for analysis of heart rate variability (HRV) in healthy subjects and in patients after acute myocardial infarction (AMI). Heart rate (HR) was recorded for 15 min in the supine position in 10 patients with AMI taking β-blockers (aged 57 ± 9 years) and in 11 healthy subjects (aged 53 ± 4 years). HRV was analyzed in the time domain (RMSSD and RMSM), the frequency domain using low- and high-frequency bands in normalized units (nu; LFnu and HFnu) and the LF/HF ratio and approximate entropy (ApEn) were determined. There was a correlation (P < 0.05) of RMSSD, RMSM, LFnu, HFnu, and the LF/HF ratio index with the ApEn of the AMI group on the 2nd (r = 0.87, 0.65,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Myocardial infarction; Heart rate variability; Autonomic nervous system; Spectral analysis; Nonlinear dynamics. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000500011 |
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| Cardozo,A.C.; Gonçalves,M.; Gauglitz,A.C.F.. |
| The aim of the present study was to assess the spectral behavior of the erector spinae muscle during isometric contractions performed before and after a dynamic manual load-lifting test carried out by the trunk in order to determine the capacity of muscle to perform this task. Nine healthy female students participated in the experiment. Their average age, height, and body mass (± SD) were 20 ± 1 years, 1.6 ± 0.03 m, and 53 ± 4 kg, respectively. The development of muscle fatigue was assessed by spectral analysis (median frequency) and root mean square with time. The test consisted of repeated bending movements from the trunk, starting from a 45º angle of flexion, with the application of approximately 15, 25 and 50% of maximum individual load, to the stand... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electromyography; Spectral analysis; Root mean square; Load lifting; Fatigue. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000700018 |
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| Abbasi,Muhammad Athar; Riaz,Sajid; Rehman,Aziz-ur-; Siddiqui,Sabahat Zahra; Shah,Syed Adnan Ali; Ashraf,Muhammad; Lodhi,Muhammad Arif; Khan,Farman Ali. |
| The aim of the present research work was to investigate the enzyme inhibitory potential of some new sulfonamides having benzodioxane and acetamide moieties. The synthesis was started by the reaction of N-2,3-dihydrobenzo[1,4]-dioxin-6-amine (1) with 4-methylbenzenesulfonyl chloride (2) in the presence of 10% aqueous Na2CO3 to yield N-(2,3-dihydrobenzo[1,4]-dioxin-6-yl)-4-methylbenzenesulfonamide (3), which was then reacted with 2-bromo-N-(un/substituted-phenyl)acetamides (6a-l) in DMF and lithium hydride as a base to afford various 2-{2,3-dihydro-1,4-benzodioxin-6-yl[(4-methylphenyl)sulfonyl]amino}-N-(un/substituted-phenyl)acetamides (7a-l). All the synthesized compounds were characterized by their IR and 1H-NMR spectral data along with CHN analysis data.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Benzodioxane; Acetamide; Spectral analysis; A-Glucosidase; Acetylcholinesterase; Molecular docking. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502019000100518 |
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| Vilibic, I; Leder, N. |
| The aim of this paper is to investigate long-period climatic variations in the Mediterranean sea level, as well as some meteorological parameters and the influence of atmospheric forcing on sea-level fluctuations. Data for the annual mean sea level at seven stations (Trieste, Genoa, Marseilles, Alicante, Oran, La Goulette and Sfax), located in the Western Mediterranean, together with mean air pressure and temperature data for Zagreb, have been spectrally analysed. Various peaks in the power, coherence and phase spectra have been detected. The period of about 5.1 years corresponds to the quasi-meridional fluctuation in the paths of Atlantic cyclones. The period of about 2.7 years may be excited by variations of currents and sea-surface temperature in the... |
| Tipo: Text |
Palavras-chave: Sea-level series; Meteorological series; Spectral analysis; Long-period climatic oscillations. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00096/20763/18389.pdf |
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| Lin, Jing-yi; Sibuet, Jean-claude; Hsu, S. |
| The acoustic basement map of the East China Sea, established by the Shanghai Offshore Petroleum Bureau with all available industry seismic data, shows the existence of a 30-km-wide, 10-km-deep basin, that we named the Ho Basin. The Ho Basin belongs to a series of elongated deep basins extending over 600 km east of the Taiwan-Sinzi Ridge and flanked to the East by a ridge named the Longwan Ridge in its northern part. This new system of basin and ridge was probably formed during middle Miocene, sometimes in between rifting episodes occurring in the Taipei Basin and Okinawa Trough. It. complements the already defined system of five belts of back-arc basins and associated arc volcanic ridges in the East China Sea, which are progressively younger from the... |
| Tipo: Text |
Palavras-chave: Depth of magnetic sources; Spectral analysis; Backarc basins; East China Sea. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1342.pdf |
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| Royer, Francois; Fromentin, Jean-marc. |
| This paper provides an exploratory analysis aiming to seek whether the colour of environmental noise theory could help in understanding the intriguing reproductive strategy of Atlantic bluefin tuna (BFT). A frequency-based approach based on spectral exponents, f(beta) with beta < 0, is chosen and applied on 10 biogeographical provinces covering the North Atlantic. The major BFT spawning area, i.e. the Mediterranean Sea, was the only one to display a pink power spectrum, whereas open ocean regions displayed more reddened fluctuations, i.e. greater variance at low frequencies. Environmental noise in the Mediterranean could, thus, offer more favourable characteristics on the long-term than the open ocean. The implications of these findings are discussed in... |
| Tipo: Text |
Palavras-chave: Thunnus thynnus; Spectral analysis; Spawning; Sea surface temperature; Environmental noise. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2437.pdf |
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| Sultan, Sar; Ahmad, F; Elghribi, Nm. |
| Analyses of the daily means of the sea level at Jeddah and Port Sudan for the year 1991 reveal that a large proportion (60%) of the energy is concentrated in the seasonal variations. The seasonal signal is approximated as the sum of an annual and semi-annual components. The amplitudes of the annual component are 20.3 and 12.7 cm respective! y and constitute about 44% of the total variance. The amplitudes of the semi-annual cycle are 9.6 cm and 7.7 cm and explain about 10% and 16% of the variance respcctively. At Jeddah cross-spectral anal ysis between the sea-level and the wind stress components shows that the annual cycle is mainly induced by the long-shore component. In contrast no correlation exists between the sea leve! and the cross-shore wind-stress... |
| Tipo: Text |
Palavras-chave: Niveau de la mer; Tension du vent; Analyse spectrale; Mer Rouge; Sea leve; Wind stress; Spectral analysis; Red Sea. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00096/20766/18392.pdf |
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| Horng, Cs; Roberts, Ap; Liang, Wt. |
| We present a 2.14-Myr astronomically tuned relative geomagnetic paleointensity record from the western Philippine Sea. Pseudosingle-domain titanomagnetite is the only magnetic mineral identified and variations in titanomagnetite concentration fall well within the accepted limits for relative paleointensity variations. No significant temporally persistent periodicities are observed in wavelet analyses of the paleointensity time series or in the rock magnetic parameters used for relative paleointensity normalization. This suggests that our paleointensity record is largely free of rock magnetic or lithological artefacts and that it represents a reliable record of geomagnetic behavior with no evidence for modulation of the field at Earth orbital periods. The... |
| Tipo: Text |
Palavras-chave: Geomagnetic paleointensity; Magnetostratigraphy; Spectral analysis; Wavelet analysis; Philippine Sea. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00224/33554/31978.pdf |
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| Registros recuperados: 35 | |
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