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Recovery Function (recovery + function)
Selected AbstractsThe Evaluation Method of Smoothing Algorithms in VoltammetryELECTROANALYSIS, Issue 22 2003Malgorzata Jakubowska Abstract The criterion for testing the influence of smoothing algorithms for the relevant parameters considered in analytical experiment is presented. The proposed approach assumes that the improvement of the whole set of measured curves should be considered. The calibration curve parameters with confidence intervals, correlation coefficient, detection limit, signal to noise ratio and parameters of recovery function are utilized for the evaluation. Performance of evaluation method is presented for several kinds of experimental noises. [source] Impaired intracortical inhibition in the primary somatosensory cortex in focal hand dystoniaMOVEMENT DISORDERS, Issue 4 2008Yohei Tamura MD Abstract Somesthetic temporal discrimination (STD) is impaired in focal hand dystonia (FHD). We explored the electrophysiological correlate of the STD deficit to assess whether this is due to dysfunction of temporal inhibition in the somatosensory inhibitory pathway or due to dysfunction in structures responsible for nonmodality-specific timing integration. Eleven FHD patients and 11 healthy volunteers were studied. STD threshold was investigated as the time interval required for perceiving a pair of stimuli as two separate stimuli in time. We also examined the somatosensory-evoked potential (SEP) in a paired-pulse paradigm. We compared STD threshold and recovery function of SEP between the groups. STD thresholds were significantly greater in FHD than in healthy volunteers. The amount of P27 suppression in the 5 ms-ISI condition was significantly less in FHD. It was also found that the STD threshold and P27 suppression were significantly correlated: the greater the STD threshold, the less the P27 suppression. Significantly less suppression of P27 with a lack of significant change in N20 indicates that the impairment of somatosensory information processing in the time domain is due to dysfunction within the primary somatosensory cortex, suggesting that that the STD deficit in FHD is more attributable to dysfunction in the somatosensory pathway. © 2007 Movement Disorder Society [source] Rapid method for determination of chlormequat residues in tomato products by ion-exchange liquid chromatography/electrospray tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 19 2002M. Careri A rapid method has been devised for the direct determination of chlormequat in tomato samples. No clean-up is required, and analysis uses ion-exchange liquid chromatography/tandem mass spectrometry interfaced with electrospray ionization (LC/ESI-MS/MS). A cation-exchange column was used with an aqueous ammonium acetate/acetonitrile mixture as the mobile phase under isocratic conditions. The method was validated in terms of detection limits (LOD), quantitation limits (LOQ), linearity, recovery, precision and accuracy. Good results in the low,µg kg,1 level were obtained for the LOD and LOQ of chlormequat in tomato samples. Comparison of solvent and matrix-matched calibration curves demonstrated the absence of significant matrix effects and the feasibility of using external calibration. Linearity was established over two orders of magnitude by performing homoscedasticity and Mandel fitting statistical tests. The absence of both constant and proportional systematic errors was verified by evaluating the recovery function, demonstrating good method accuracy. Excellent precision in terms of intra-day repeatability was calculated (RSD% <3.4). Extraction recoveries from tomato products were calculated, by using a labelled internal standard (d4 -chlormequat), to be in the 93,±,5,99,±,7% range. The applicability of the method to the determination of chlormequat residues in tomato products was demonstrated. Copyright © 2002 John Wiley & Sons, Ltd. [source] Somatosensory disinhibition in dystoniaMOVEMENT DISORDERS, Issue 4 2001Emma Frasson MD Abstract Despite the fact that somatosensory processing is inherently dependent on inhibitory functions, only excitatory aspects of the somatosensory feedback have so far been assessed in dystonic patients. We studied the recovery functions of spinal N13, brainstem P14, parietal N20, P27, and frontal N30 somatosensory evoked potentials (SEPs) after paired median nerve stimulation in 10 patients with dystonia and in 10 normal subjects. The recovery functions were assessed (conditioning stimulus: S1; test stimulus: S2) at interstimuls intervals (ISIs) of 5, 20, and 40 ms. SEPs evoked by S2 were calculated by subtracting the SEPs of the S1 only response from the SEPs of the response to the paired stimuli (S1 + S2), and their amplitudes were compared with those of the control response (S1) at each ISI considered. This ratio, (S2/S1)*100, investigates changes in the excitability of the somatosensory system. No significant difference was found in SEP amplitudes for single stimulus (S1) between dystonic patients and normal subjects. The (S2/S1)*100 ratio at the ISI of 5 ms did not significantly differ between dystonic patients and normal subjects, but at ISIs of 20 and 40 ms, this ratio was significantly higher in patients than in normals for spinal N13 and cortical N20, P27, N30 SEPs. These findings suggest that in dystonia there is an impaired inhibition at spinal and cortical levels of the somatosensory system which would lead to an abnormal sensory assistance to the ongoing motor programs, ultimately resulting in the motor abnormalities present in this disease. © 2001 Movement Disorder Society. [source] | ||||||||||