CMC is more than a measure of corticospinal tract integrity in acute stroke patients

In healthy subjects, motor cortex activity and electromyographic (EMG) signals from contracting contralateral muscle show coherence in the beta (15-30 Hz) range. Corticomuscular coherence (CMC) is considered a sign of functional coupling between muscle and brain. Based on prior studies, CMC is altered in stroke, but functional significance of this finding has remained unclear. Here, we examined CMC in acute stroke patients and correlated the results with clinical outcome measures and corticospinal tract (CST) integrity estimated with diffusion tensor imaging (DTI). During isometric contraction of the extensor carpi radialis muscle, EMG and magneto encephalographic oscillatory signals were recorded from 29 patients with paresis of the upper extremity due to ischemic stroke and 22 control subjects. CMC amplitudes and peak frequencies at 13-30 Hz were compared between the two groups. In the patients, the peak frequency in both the affected and the unaffected hemisphere was significantly (p < 0.01) lower and the strength of CMC was significantly (p < 0.05) weaker in the affected hemisphere compared to the control subjects. The strength of CMC in the patients correlated with the level of tactile sensitivity and clinical test results of hand function. In contrast, no correlation between measures of CST integrity and CMC was found. The results confirm the earlier findings that CMC is altered in acute stroke and demonstrate that CMC is bidirectional and not solely a measure of integrity of the efferent corticospinal tract.Peer reviewe

Remineralization of demineralized dentin using a dual analog system.

ObjectiveImproved methods are needed to remineralize dentin caries in order to promote conservation of dentin tissue and minimize the surgical interventions that are currently required for clinical treatment. Here, we test the hypothesis that bulk substrates can be effectively mineralized via a dual analog system proposed by others, using a tripolyphosphate (TPP) "templating analog" and a poly(acrylic acid) (PAA) or poly(aspartic acid) (pAsp) "sequestration analog," the latter of which generates the polymer-induced liquid-precursor (PILP) mineralization process studied in our laboratory.Material &amp; methodsDemineralized human dentin slices were remineralized with and without pre-treatment with TPP, using either PAA or pAsp as the PILP process-directing agent. A control experiment with no polymer present was used for comparison.ResultsNo mineralization was observed in any of the PAA groups. In both the pAsp and no polymer groups, TPP inhibited mineralization on the surfaces of the specimens but promoted mineralization within the interiors. Pre-treatment with TPP enhanced overall mineralization of the pAsp group. However, when analysed via TEM, regions with little mineral were still present.ConclusionPoly(acrylic acid) was unable to remineralize demineralized dentin slices under the conditions employed, even when pre-treated with TPP. However, pre-treatment with TPP enhanced overall mineralization of specimens that were PILP-remineralized using pAsp

Complex, but not quite complex enough : The turn to the complexity sciences in evaluation scholarship

This document is the Accepted Manuscript version of the following article: Chris Mowles, ‘Complex, but not quite complex enough: The turn to the complexity sciences in evaluation scholarship’. The final, definitive version of this paper has been published in Evaluation, Vol. 20 (2): 160-175, April 2014, doi: https://doi.org/10.1177/1356389014527885 , published by SAGE Publishing. All rights reserved.This article offers a critical review of the way in which some scholars have taken up the complexity sciences in evaluation scholarship. I argue that there is a tendency either to over-claim or under-claim their importance because scholars are not always careful about which of the manifestations of the complexity sciences they are appealing to, nor do they demonstrate how they understand them in social terms. The effect is to render ‘complexity’ just another volitional tool in the evaluator’s toolbox subsumed under the dominant understanding of evaluation, as a logical, rational activity based on systems thinking and design. As an alternative I argue for a radical interpretation of the complexity sciences, which understands human interaction as always complex and emergent. The interweaving of intentions in human activity will always bring about outcomes that no one has intended including in the activity of evaluation itself.Peer reviewe

Characterization of TiO2 nanoparticles in langmuir-blodgett films

In this work we have synthesized TiO2 nanoparticles, using either a sol–gel base catalysed process in the interior of CTAB reversed micelles (TiO2 CTAB sol), or the neutralization of a TiO2/H2SO4 solution in the interior of AOT reversed micelles. From the absorption and emission data of the TiO2 nanoparticles it is possible to conclude that in the sol–gel route there remains alkoxide groups in the structure, originating transitions lower than the energy gap of TiO2 semiconductor. These transitions disappear in the neutralization procedure, where the alkoxide groups are absent in the structure. We have assigned the observed indirect and direct optical transitions according to the anatase band structure. TiO2 Langmuir-Blodgett (LB) films were prepared either by direct deposition of titanium isopropoxide or by deposition of the TiO2 CTAB sol. These films showed photoluminescence, which was attributed to band-gap emission and to surface recombination of defect states

Vibrational dynamics of crystalline L-alanine

The authors report a new, complete vibrational analysis of L-alanine and L-alanine-d{sub 4} which utilizes IINS intensities in addition to frequency information. The use of both isotopomers resulted in a self-consistent force field for and assignment of the molecular vibrations in L-alanine. Some details of the calculation as well as a comparison of calculated and observed IINS spectra are presented. The study clarifies a number of important issues on the vibrational dynamics of this molecule and presents a self-consistent force field for the molecular vibrations in crystalline L-alanine

The effect of water immersion on short-latency somatosensory evoked potentials in human

<p>Abstract</p> <p>Background</p> <p>Water immersion therapy is used to treat a variety of cardiovascular, respiratory, and orthopedic conditions. It can also benefit some neurological patients, although little is known about the effects of water immersion on neural activity, including somatosensory processing. To this end, we examined the effect of water immersion on short-latency somatosensory evoked potentials (SEPs) elicited by median nerve stimuli. Short-latency SEP recordings were obtained for ten healthy male volunteers at rest in or out of water at 30°C. Recordings were obtained from nine scalp electrodes according to the 10-20 system. The right median nerve at the wrist was electrically stimulated with the stimulus duration of 0.2 ms at 3 Hz. The intensity of the stimulus was fixed at approximately three times the sensory threshold.</p> <p>Results</p> <p>Water immersion significantly reduced the amplitudes of the short-latency SEP components P25 and P45 measured from electrodes over the parietal region and the P45 measured by central region.</p> <p>Conclusions</p> <p>Water immersion reduced short-latency SEP components known to originate in several cortical areas. Attenuation of short-latency SEPs suggests that water immersion influences the cortical processing of somatosensory inputs. Modulation of cortical processing may contribute to the beneficial effects of aquatic therapy.</p> <p>Trial Registration</p> <p>UMIN-CTR (UMIN000006492)</p

Inter- versus intramodal integration in sensorimotor synchronization: a combined behavioral and magnetoencephalographic study

Although the temporal occurrence of the pacing signal is predictable in sensorimotor synchronization tasks, normal subjects perform on-the-beat-tapping to an isochronous auditory metronome with an anticipatory error. This error originates from an intermodal task, that is, subjects have to bring information from the auditory and tactile modality to coincide. The aim of the present study was to illuminate whether the synchronization error is a finding specific to an intermodal timing task and whether the underlying cortical mechanisms are modality-specific or supramodal. We collected behavioral data and cortical evoked responses by magneto-encephalography (MEG) during performance of cross- and unimodal tapping-tasks. As expected, subjects showed negative asynchrony in performing an auditorily paced tapping task. However, no asynchrony emerged during tactile pacing, neither during pacing at the opposite finger nor at the toe. Analysis of cortical signals resulted in a three dipole model best explaining tap-contingent activity in all three conditions. The temporal behavior of the sources was similar between the conditions and, thus, modality independent. The localization of the two earlier activated sources was modality-independent as well whereas location of the third source varied with modality. In the auditory pacing condition it was localized in contralateral primary somatosensory cortex, during tactile pacing it was localized in contralateral posterior parietal cortex. In previous studies with auditory pacing the functional role of this third source was contradictory: A special temporal coupling pattern argued for involvement of the source in evaluating the temporal distance between tap and click whereas subsequent data gave no evidence for such an interpretation. Present data shed new light on this question by demonstrating differences between modalities in the localization of the third source with similar temporal behavior

Effects of mental practice embedded in daily therapy compared to therapy as usual in adult stroke patients in Dutch nursing homes: design of a randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>Mental practice as an additional cognitive therapy is getting increased attention in stroke rehabilitation. A systematic review shows some evidence that several techniques in which movements are rehearsed mentally might be effective but not enough to be certain. This trial investigates whether mental practice can contribute to a quicker and/or better recovery of stroke in two Dutch nursing homes. The objective is to investigate the therapeutic potential of mental practice embedded in daily therapy to improve individually chosen daily activities of adult stroke patients compared to therapy as usual. In addition, we will investigate prognostic variables and feasibility (process evaluation).</p> <p>Methods</p> <p>A randomised, controlled, observer masked prospective trial will be conducted with adult stroke patients in the (sub)acute phase of stroke recovery. Over a six weeks intervention period the control group will receive multi professional therapy as usual. Patients in the experimental group will be instructed how to perform mental practice, and will receive care as usual in which mental practice is embedded in physical, occupation and speech therapy sessions. Outcome will be assessed at six weeks and six months. The primary outcome measure is the patient-perceived effect on performance of daily activities as assessed by an 11-point Likert Scale. Secondary outcomes are: Motricity Index, Nine Hole Peg Test, Barthel Index, Timed up and Go, 10 metres walking test, Rivermead Mobility Index. A sample size of the patients group and all therapists will be interviewed on their opinion of the experimental program to assess feasibility. All patients are asked to keep a log to determine unguided training intensity.</p> <p>Discussion</p> <p>Advantages and disadvantages of several aspects of the chosen design are discussed.</p> <p>Trial registration</p> <p>ISRCTN27582267</p

Spreading of complex regional pain syndrome: not a random process

Complex regional pain syndrome (CRPS) generally remains restricted to one limb but occasionally may spread to other limbs. Knowledge of the spreading pattern of CRPS may lead to hypotheses about underlying mechanisms but to date little is known about this process. The objective is to study patterns of spread of CRPS from a first to a second limb and the factors associated with this process. One hundred and eighty-five CRPS patients were retrospectively evaluated. Cox’s proportional hazards model was used to evaluate factors that influenced spread of CRPS symptoms. Eighty-nine patients exhibited CRPS in multiple limbs. In 72 patients spread from a first to a second limb occurred showing a contralateral pattern in 49%, ipsilateral pattern in 30% and diagonal pattern in 14%. A trauma preceded the onset in the second limb in 37, 44 and 91%, respectively. The hazard of spread of CRPS increased with the number of limbs affected. Compared to patients with CRPS in one limb, patients with CRPS in multiple limbs were on average 7 years younger and more often had movement disorders. In patients with CRPS in multiple limbs, spontaneous spread of symptoms generally follows a contralateral or ipsilateral pattern whereas diagonal spread is rare and generally preceded by a new trauma. Spread is associated with a younger age at onset and a more severely affected phenotype. We argue that processes in the spinal cord as well as supraspinal changes are responsible for spontaneous spread in CRPS