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PubMed2002

The spectral analysis of syllables in patients using dentures.

Changes in the oral cavity resulting from the loss of teeth and the ensuing reconstruction of a set of teeth by dentures (partial or complete) may cause changes in the speech and voice of the patient. The aim of the present investigation was to study the changes in speech and voice in patients suffering from teeth loss and the degree of speech improvement using dentures. Voice and speech parameters of a set of tested syllables were analysed in 10 patients at the 2nd Clinic of Stomatology. The analysis was carried out by means of an FFT, SoundForge 5.0 programme. Differently expressed acoustic changes in both consonants and vowels were ascertained in a percentage of the patients under examination. These concerned especially the sibilant ("s", "(see text)"), labiodental ("f", "v") and vibrating ("r", "(see text)") consonants. Changes in the FFT spectrum and air leakage in constrictive consonants were also found. In some patients the vowels, especially the closed ones ("i", "u"), may change their fundamental frequency and show noise admixture manifested as a blurred delimitation of the formants. A denture should, inter alia, render it possible for the patient to produce the same articulation to which he/she had been accustomed before the loss of teeth. For the construction of dentures the most important factors from a phonetic point of view appear to be the following: overbite, overjet, the height of the plate, the thickness of the palatal material, the incisor position, and the modelling of the ruga palatina on the hard palate. In case of wrong denture construction the acoustic changes may continue, resulting in the patient's stress load dependent upon sex, age, psychic condition and seriousness of the problem.

Aged↗
PubMed1996

Spectral analysis in cyclic changes of human sleep evaluation.

In this study cyclic changes of human sleep structure were examined. For whole-night polysomnograms of 35 healthy volunteers of both sexes, manual hypnograms were created and divided into NREM-REM cycles. EEG signals from C3-A2 derivation were analysed by computer using a Fast Fourier Transform (FFT). For consecutive NREM-REM cycles of individual sleep stages, EEG power density contents for delta, theta, alpha, sigma and beta waves were analysed. For consecutive sleep cycles, a clear decrease in NREM sleep duration, especially slow wave sleep duration, was obtained. In addition, a decrease in power density of delta waves was observed. For consecutive sleep cycles, increases in REM sleep duration and in power density of theta and alpha waves were obtained. In consecutive sleep cycles, high amplitude delta slow waves are replaced by higher frequency and lower amplitude waves. Thus stages of NREM sleep are replaced by stages of REM.

Adult↗
PubMed1978

Structural investigation of the antibiotic ristomycin A. 13C-NMR spectral analysis of the interglycosidic linkages of the heterotetrasaccharide side-chain.

By 13C-NMR studies on Ia, IIa, IIb and IVa obtained by the chemical degradation of ristomycin A and on several synthetic model compounds it has been proved that an O-beta-D-arabinopyranosyl-(1 leads to 2)-O-alpha-D-mannopyranosyl-(1 leads to 2)-O-[alpha-L-rhamnopyranosyl-(1 leads to 6)]-D-glucopyranosyl heterotetrasaccharide moiety is connected to the aglycone of the antibiotic.

Chemical Phenomena↗
PubMed1982

Conformations of protein moieties and chromophore-protein interactions in the antitumor antibiotics, macromomycin and auromomycin, characterized by IR and CD spectral analysis.

The free chromophores (chr) extracted from macromomycin (MCR) and auromomycin (AUR) showed different IR spectra in KBr tablets and different CD spectra in ethanol or methanol solution. Chr-MCR contained a greater amount of alkyl moieties than chr-AUR as shown by much stronger IR absorbance at 2960 cm-1. The IR spectra of MCR, AUR and their apo-proteins (apo) in D2O showed that major parts of the proteins formed antiparallel beta-pleated sheets. Apo-AUR exhibited a faster H-D exchange than AUR, indicating existence of more extensive "nonmotile parts" of the beta-sheet formed through the chromophore-protein interaction in AUR. However, apo-MCR exhibited a slightly faster H-D exchange than MCR. This difference presumably was associated with the lower content of the chromophore (1.4 wt%) in MCR than that in AUR (8.2 wt%). Chr-AUR was extracted from the intact antibiotic with methanol more efficiently than chr-MCR. Further, a marked bathochromic effect by the chromophore-protein interaction was observed in the CD and UV absorption for MCR, but not for AUR. These results indicated that chr-MCR was tightly bound to the protein moiety while most of chr-AUR was loosely bound.

Anti-Bacterial Agents↗
PubMed1993

Conformation studies on and assessment by spectral analysis of the protein-chromophore interaction of the macromolecular antitumor antibiotic C-1027.

Characterization of the secondary structure of the antitumor antibiotic C-1027 has been made from a comparison of C-1027 and its apoprotein by various analytical means. The results indicated the antibiotic to be abundant in beta-structure by measurements of Fourier-transform infrared (FT-IR) spectroscopy and the circular dichroism (CD) spectrum, and by a prediction of the secondary structure based on the amino acid sequence of the peptide. In comparison of the IR spectra of their proteins in D2O, the apoprotein exhibited a faster H-D exchange than C-1027, indicating an increase in the "non-motile parts" of the beta-sheets formed through the protein-chromophore interaction in holo-C-1027. The prediction of hydropathic index indicated the hydrophobic residues of the apoprotein to be predominantly located in the beta-sheet structures, suggesting hydrophobic interaction in the binding between chromophore and apoprotein. Further, the interaction between chromophore and apoprotein was detected by a fluorescence method. The result showed the dissociation constant (Kd) to be 6.88 x 10(-5) M, indicating that the chromophore is tightly bound to the protein moiety.

Amino Acid Sequence↗
PubMed1997

Spectral analysis of 24 h blood pressure monitoring in the assessment of trough: peak ratio. A randomized, placebo-controlled, cross-over comparison of ramipril and enalapril.

BACKGROUND: The ratio between the magnitude of blood pressure reduction during the steady-state dosage interval (trough) and the maximum blood pressure reduction (peak) is an integrated in-vivo index both of the pharmacokinetic properties and of pharmacodynamic activity of an antihypertensive drug. Angiotensin converting enzyme inhibitors are often characterized by a low (often lower than 50%) trough: peak ratio but no direct drug comparisons are available. OBJECTIVE: To compare the absolute blood pressure reduction and the trough: peak ratio of daily doses of two angiotensin converting enzyme inhibitors, 5 mg ramipril and 10 mg enalapril. METHOD: After a 1-month wash-out and a 2-week placebo run-in, 25 mild hypertensives aged 47 +/- 4 years (17 men and eight women) were randomly assigned to treatments separated by a 2-week interval. Ambulatory blood pressure monitoring was performed and trough: peak ratio was calculated by the fast Fourier transform analysis of placebo-effect-subtracted data. RESULTS: After 1 month of ramipril treatment, 24 h blood pressure decreased from 139 +/- 10 to 129 +/- 11 mmHg for systolic (P < 0.05) and from 89 +/- 8 to 81 +/- 5 mmHg for diastolic blood pressure (P < 0.01). Also enalapril treatment caused a significant 24 h reduction in blood pressure both for systolic (to 132 +/- 7 mmHg, P < 0.05) and for diastolic blood pressure (to 84 +/- 5 mmHg, P < 0.05). Placebo caused a 24 h reduction in blood pressure (to 136 +/- 8 mmHg for systolic and 87 +/- 5 mmHg for diastolic blood pressure, NS, versus wash-out period). The two drugs were equally effective in reducing ambulatory blood pressure, but ramipril produced a trough: peak ratio significantly higher than that with enalapril both for systolic (48 +/- 11%, range 34-74%, versus 38 +/- 11%, range 21-67%, P < 0.005)and for diastolic blood pressure (47 +/- 11%, range 30-79 %, versus 37 +/- 12%, range 21-68%, P < 0.05). CONCLUSION: The low trough : peak ratios could have been due to the daily pattern of blood pressure of mild hypertensives, many of whom are normotensives at night-time, so that the main antihypertensive effect is exerted during daytime rather than during the night or early morning.

Journal Article↗
PubMed1999

Higher-order spectral analysis in laser-Doppler flowmetry signal processing.

This paper presents an application of higher order statistics and spectra to the problem of laser-Doppler Flowmetry (LDF) for microcirculation monitoring. The proposed signal processing technique computes the bispectra of LDF signals after appropriate pre-processing and extracts features which can be used for classification of the signals to a normal or patient category. Bispectra are defined in terms of the third-order moments or cumulants of signals and are shown to contain valuable information for the above classification of LDF signals. Experimental studies, including (a) a set of 17 normal subjects and 69 patients with Raynaud's phenomenon and (b) 50 LDF-signals separated to four groups from patients that have different pathologic characteristics, are described and results are presented which illustrate the performance of the proposed approach when applied to the LDF signals.

Adult↗
PubMed1998

Spectral analysis of heart rate and arterial pressure variability after nitric oxide synthase inhibition.

The experiments were performed on male, conscious Wistar rats. Femoral arterial pressure was registered by Statham GOULD P23 ID pressure transducer connected to MP 100WS BIOPAC work station after analog to digital conversion during 40 minutes long control period. Nitric oxide synthase inhibition was performed by injection of 100 microliters, 10 mg/kg b.w. N-omega-nitro-L-arginine methyl ester (L-NAME) in saline through femoral vein catheter. Twenty minutes later arterial pressure registration was started and was continued for 40 minutes. The pulse-by-pulse values of systolic, diastolic and mean arterial pressure as well as the pulse intervals were measured by peak and rate detectors of the AcqKnowledge 2.0 software. Row data were processed using a virtual instrument developed in our laboratory in the graphical programming environment Lab VIEW 3.1.1. L-NAME increased systolic, diastolic and mean arterial pressure by 16.6%, 25% and 35%, respectively. The PMF/PHF ratio in heart rate spectrum decreased, indicating an increased vagal effect on the heart. Nitric oxide synthase inhibition increased the low-frequency component of systolic arterial blood pressure variability by 39.5%. Nitric oxide is a physiological regulator of rapid fluctuations of arterial blood pressure.

Animals↗
PubMed2000

Reminiscence therapy using odor in alcohol-dependent patients--psychophysiological evaluation and psychological evaluation; power spectral analysis of heart rate variability.

OBJECTIVE: This research was based on the hypothesis that when alcohol-dependent patients describe themselves, awakening of emotion by affirmative odor stimulation may facilitate memory reframing focusing on more affirmative emotion and memories. To prove the hypothesis, physiological changes accompanied by emotional awakening were evaluated by measuring the autonomic activity. In addition, subjective evaluation by a self-report manner was examined to investigate the effectiveness of Reminiscence Therapy (RT) using odor in alcohol-dependent patients. SUBJECTS: Thirty-four patients who met the DSM-IV criteria of alcohol-related disorders and were hospitalized in a ward specialized to alcohol dependence therapy. METHODS: Each patient underwent a one-to-one interview twice. For counterbalance, one interview was performed with odor stimulation using an odor with a relaxing effect that recall pleasant emotion, and the other was without odor stimulation. As the evaluation indices of physiological changes accompanied by emotional awakening, index of autonomic function (HRV; Heart rate variability) for objective evaluation and psychological indices (STAI; State-Trait Anxiety Inventory VAS; Visual Analog Scale) for subjective evaluation were measured. RESULTS: 1) Objective evaluation: Regarding the evaluation index of the autonomic function, the sympathetic nervous system activity (LF/HF; low frequency component/high frequency component ratio) was significantly inhibited by odor stimulation (p < 0.05). 2) Subjective evaluation: Compared to the state prior to interview, state anxiety judged by STAI was significantly decreased after interview (p < 0.01). The VAS score was significantly decreased after interview regardless of the presence or absence of odor stimulation (p < 0.0001). CONCLUSIONS: A reduction in state anxiety was observed. The effect of odor was not significant on the subjective evaluation, but the objective evaluation suggested that the odor inhibited the sympathetic nervous system. Thus, it was suggested that odor can be used in RT, that is, emotional changes due to stimulation of odor may be applicable in RT.

Adult↗
PubMedDate not supplied

[Multiband spectral analysis and standardized markers of the slope of pediatric electroencephalograms].

INTRODUCTION: The infantile electroencephalogram has been studied in connection with many cognitive disabilities. Although normal resting infantile bioelectric recordings are known, the cortical distribution of electroencephalographic frequencies during other sensory and/or cognitive mental processes is less well known. OBJECTIVE: Our interest is based on the description of EEGs of a homogeneous sample of healthy children and their relation to intellectual activities. MATERIAL AND METHODS: The sample studied was made up of 13 healthy children with an average age of 9.3 +/- 1.3 years, on whom two types of tests of attention were done. One of the tasks was a simple auditory memory test and consisted of the spoken repetition of a series of numbers previously heard, which was of variable length. The second test consisted of the identification and crossing out of one face of a series of three faces, which included one which was different from the others. The methodology chosen was electroencephalographic measurement in the frequency and temporal domains. RESULTS AND CONCLUSIONS: There was a relative increase in beta frequencies in all cortical sites which was significant in T3 and T4 with the auditory test and in all electrodes with the visual test. During auditory testing reduction in the alpha frequency was observed in frontotemporal regions. The greatest cortical variations of beta frequency occurred, in the facial test, in the electrodes O2, T6, O1, T5 and T3. The values of Hjorth complexity obtained varied within the interval 1 to 3, which was a considerably lower interval than that found in adult populations.

Attention↗