74 research outputs found
Voice abnormalities and their relation with motor dysfunction in Parkinson's disease
No full textObjective To evaluate changes in perceptual and several acoustic parameters of voice in patients with Parkinson's disease (PD ) and to find out any relation with these parameters and motor components of Unified Parkinson's Disease Rating Scale (UPDRS) in this patient group. Materials and methods Twenty patients with PD (12 male and 8 female) were given objective and subjective voice tests and results were compared with those of 20 age- and sex-matched controls. Patient's perceptual voice analysis was assessed using GRBAS scale including Grade of Dysphonia, Roughness, Breathiness, Asthenia and Strain items. Measurements for objective voice analysis, acoustic assessment tests including frequency perturbation [jitter (jitt)%], intensity perturbation [shimmer (shim)%], noise to harmonic ratio (NHR), fundamental frequency (F0), variability of fundamental frequency (vF0), diadochokinetic rate (DDK) and maximum phonation time (MPT) were used. An assessment of disability caused by voice disorders was scored according to the Voice Handicap Index (VHI) by the patient. All subjects also underwent videolaryngostroboscopic (VLS) examination. Motor components of UPDRS and acoustic parameters of voice were investigated for any correlations. Results Compared with controls, roughness (P = 0.15), breathiness (P = 0.004) and asthenia (P = 0.031) values of males and breathiness (P = 0.043) and asthenia (P = 0.023) values of females were higher in patients with PD. Mean VHI scores of patients with PD were higher for both male and female patients (P = 0.0001 for male, P = 0.002 for female). The mean values for MPT (P = 0.02) and DDK (P = 0.025) were shorter in patients with PD. Jitt%, shim% and mean F0 values were similar among the two groups. But mean vF0 values were significantly higher in male patients with PD (P = 0.05). On VLS examination, non-closure glottic pattern was found to be more frequent in the PD group. Conclusion Although it is well known that pathophysiological changes in PD affect the voice, the present study found only few significant correlations between motor component of UPDRS and voice parameters
Studies on the macroscopic protonation constants of some alpha-amino acids in ethanol-water mixtures.
No full textBoth to demonstrate,whether the predominant species are dipolar ion or the neutral form and to predict the change of dipolar form to neutral form ratio in ethanol-water mixtures, the macroscopic protonation constants of eight alpha-amino acid (glycine, L-alanine, L-valine, L-leucine, L-phenylalanine, L-serine, L-methionine, and L-isoleucine) were determined potentiometrically in 20- 80% (v/v) ethanol-water mixtures at 25degreesC with an ionic strength of 0.10 M. The calculation of the constants was carried out using a PKAS computer program. The effect of solvent composition on the protonation constants and the dipolar ionic to neutral form ratio of these acids in the mixed solvents are discussed. One can conclude that the dipolar form of amino acids, HA(+/-) dominates in ethanol-water Mixtures. (C) 2002 Elsevier Science (USA). All rights reserved
Potentiometric studies on the protonation constants and solvation of some α-amino acid methyl- and ethyl esters in ethanol-water mixtures
No full text960-962The
stoichiometric protonati on constants of 15 esters (methyl and ethyl esters of
glycine, L-alanine, L -valine, L - leucine, L
-phenylalanine, L -serine, L -methionine and methyl ester
of L -isoleucine) in 20-80% (v/v) ethanol-water mixtures have
been determined. The effect of solvent on α -amino acid methyl- and ethyl
esters have also been determined at ionic strength of 0. 1 M NaCl and at
25°C under nitrogen atmosphere. A potentiometric method is used
and the calculation of the constants has been carried out using PKAS
computer programme. The logarithm of the protonation constants of
α-amino acid esters is found to decrease linearly with increase in ethanol
contents. The variation of these constants is discussed on the basis of
specific solute-solvent interactions
Growth and structure of authorship and co-authorship network in the strategic management realm: Evidence from the Strategic Management Journal
No full textAbstractThe main objective of this study is to investigate the intellectual structure and evolution of author collaborations from articles published in the Strategic Management Journal between 1980 and 2014. This assessment includes the general view of authorship, authorship patterns, author productivity, ranking of authors, visualization of the co-authorship network, comparison of strategic management co-authorship network attributes with those of other disciplines, the evolution of main components and core authors in the networks by period, discussions on whether the strategic management network fits with the small world network theory, individual network attributes such as degree centrality, Bonacich's power index, closeness centrality, and betweenness centrality. Finally, the authors provide an inclusive evaluation of the results, limitations, and suggestions for future research
Morbilliform drug eruption due to pegylated α-interferon can show complete regression after switching to non-pegylated interferon
No full textPegylated or non-pegylated alpha-interferon are frequently used medications for the treatment of both chronic hepatitis B and chronic hepatitis C. Skin disorders, which are mainly comprised of eczematous dermatitis, are frequently seen during treatment with this drug. However, drug eruption or morbilliform eruptions due to interferons have been rarely reported so far. We herein describe a patient who developed morbilliform drug eruption under treatment with pegylated interferon. She was able to continue treatment after switching from pegylated interferon to conventional interferon
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