Promene ekscitabilnosti motorne kore udružene sa zamorom mišića kod obolelih od Parkinsonove bolesti

Background/Aim. Transcranial magnetic stimulation (TMS) is a standard technique for noninvasive assessment of changes in central nervous system excitability. The aim of this study was to examine changes in responses to TMS in patients suffering from Parkinson's disease (PD) during sustained submaximal isometric voluntary contraction [60% of maximal voluntary contraction (MVC)] of the adductor pollicis muscle, as well as during a subsequent recovery period. Methods. Cortical excitability was tested by single TMS pulses of twice of the motor threshold intensity applied over the vertex. Testing was carried out during the sustained contraction phase every 10 s before and every 5 s after the endurance point, as well as at rest and during brief 60% MVC contractions before (control), immediately after the sustained contraction, and at 5 min intervals during the recovery period. Results. Although the PD patients could sustain the contraction at the required level for as long period of time as the healthy subjects (though contraction level subsided more rapidly after the endurance point), effects of muscle fatigue on the responses to TMS were different. In contrast to the findings observed in the healthy people where motor evoked potentials (MEP) and EMG silent period (SP) in fatigued muscle gradually diminished during contraction up to the endurance point, and increased thereafter, in the majority of patients no changes occurred in MEP size (peak and area) of the adductor pollicis muscle, either before or after the endurance point. On the other hand, changes in the SP of this muscle differed among the subjects, showing a gradual increase, a decrease or no changes in duration. The trends of changes in both MEP size and SP duration in the musculus brachioradialis varied among the tested PD patients, without any consistent pattern, which was in contrast with the findings in the healthy people where both measures showed a gradual increase from the beginning of the sustained contraction. A complete dissociation between changes in MEP and SP during fatigue was also of note, which differed sharply from the findings in the healthy people in who fatigue induced changes in these measures followed identical patterns. Conclusion. These results in the PD patients suggest the presence of impairment and/or compensatory changes in mechanisms responsible for adaptation of voluntary drive as well as for matching between cortical excitation and inhibition which become manifest in demanding motor tasks such as those imposed by muscle fatigue.Uvod/Cilj. Transkranijalna magnetna stimulacija (TMS) je standardna tehnika za neinvazivnu procenu promena ekscitabilnosti centralnog nervnog sistema. Cilj rada je bio da se prikažu promene odgovora na TMS kod obolelih od Parkinsonove bolesti (PB) za vreme trajanja submaksimalne voljne izometrijske kontrakcije [60% maksimalne voljne kontrakcije (MVK)] mišića adductor pollicis, kao i tokom perioda oporavka. Metode. Kortikalna ekscitabilnost testirana je TMS pulsevima dvostruko većeg intenziteta od motornog praga. Testiranje je vršeno za vreme održavanja kontrakcije na svakih 10 s do tačke izdržljivosti i na svakih 5 s posle toga, a, takođe, u miru kao i za vreme kratkotrajnih 60% MVK u periodu pre (kontrola), neposredno posle održavanja kontrakcije, i u intervalima od pet minuta za vreme perioda oporavka. Rezultati. Iako su bolesnici sa PB mogli da održavaju zahtevani nivo kontrakcije jednako dugo kao i zdravi ispitanici (mada je nivo opadao brže nakon tačke izdržljivosti), efekti mišićnog zamora na odgovor izazvan TMS-om bili su različiti. Za razliku od zdravih ispitanika kod kojih se motorni evocirani potencijali (MEP) i trajanje perioda EMG tišine (PT) u zamaranom mišiću postepeno smanjuju tokom kontrakcije do tačke izdržljivosti, a zatim rastu, kod većine bolesnika nije došlo do promena veličine (maksimalna amplituda i površina) MEP mišića adductor pollicis, bilo pre ili posle tačke izdržljivosti. S druge strane, promene PT ovog mišića su se razlikovale među ispitanicima, pokazujući bilo postepeno povećanje, smanjenje ili odsustvo promena. Promene kako amplitude MEP tako i trajanje PT u EMG mišića brahioradialisa varirale su među bolesnicima sa PB, bez nekog dominantnog obrasca, po čemu su se, takođe, razlikovale od promena nađenih kod zdravih ispitanika, kod kojih su se oba parametra postepeno povećavala od početka održavanja tonične kontrakcije. Upadljiva je, takođe, i potpuna disocijacija između promena MEP i PT tokom zamora, što je u oštroj suprotnosti sa nalazom kod zdravih ispitanika gde su promene ovih parametara pratile identičan obrazac. Zaključak. Rezultati kod bolesnika sa PB ukazuju na postojanje oštećenja i/ili kompenzatornih promena mehanizmima odgovornih za adaptaciju voljne pobude i usklađivanja kortikalne eksitacije i inhibicije, koji se manifestuju tokom mišićnog zamora i u drugim zahtevnim motornim zadacima

Electrochemical synthesis and characterization of basic bismuth nitrate [Bi6O5(OH)3](NO3)5·2H2O: a potential highly efficient sorbent for textile reactive dye removal

A new method of synthesis was developed for the preparation of basic bismuth nitrate [Bi6O5(OH)3](NO3)5·2H2O (ECBBN). Electrochemical synthesis of the material was carried out by galvanostatic electrodeposition from an acidic Bi(III) solution on a Ti substrate and further thermal treatment in air at 200 °C. Characterization of ECBBN was conducted by employing SEM–EDX, N2 adsorption, XRD and FTIR, and its pI was also determined. The analyses showed that the material obtained was pure [Bi6O5(OH)3](NO3)5·2H2O. Morphologically, ECBBN aggregates were composed of crystals, some smaller than 50 nm. Electrochemically synthesized sorbent (ECBBN) was used for the removal of the textile dye Reactive Blue 19 (RB19) from deionized water and model solutions of polluted river water, and it showed considerably superior sorption performance compared to other inorganic sorbents synthesized by conventional methods reported in the literature. A kinetic study suggests that the sorption process is both under reaction and diffusion control. Equilibration of the sorption process was attained in several minutes, i.e. the sorption process is very fast. The sorption equilibrium data were well interpreted by the Langmuir, Redlich–Peterson and Brouers–Sotolongo isotherm. Using Langmuir isotherm, the maximum sorption capacity of ECBBN was reached at pH 2 and was 1049.19 mg g−1

Cognitive vision system for control of dexterous prosthetic hands: Experimental evaluation

<p>Abstract</p> <p>Background</p> <p>Dexterous prosthetic hands that were developed recently, such as SmartHand and i-LIMB, are highly sophisticated; they have individually controllable fingers and the thumb that is able to abduct/adduct. This flexibility allows implementation of many different grasping strategies, but also requires new control algorithms that can exploit the many degrees of freedom available. The current study presents and tests the operation of a new control method for dexterous prosthetic hands.</p> <p>Methods</p> <p>The central component of the proposed method is an autonomous controller comprising a vision system with rule-based reasoning mounted on a dexterous hand (CyberHand). The controller, termed cognitive vision system (CVS), mimics biological control and generates commands for prehension. The CVS was integrated into a hierarchical control structure: 1) the user triggers the system and controls the orientation of the hand; 2) a high-level controller automatically selects the grasp type and size; and 3) an embedded hand controller implements the selected grasp using closed-loop position/force control. The operation of the control system was tested in 13 healthy subjects who used Cyberhand, attached to the forearm, to grasp and transport 18 objects placed at two different distances.</p> <p>Results</p> <p>The system correctly estimated grasp type and size (nine commands in total) in about 84% of the trials. In an additional 6% of the trials, the grasp type and/or size were different from the optimal ones, but they were still good enough for the grasp to be successful. If the control task was simplified by decreasing the number of possible commands, the classification accuracy increased (e.g., 93% for guessing the grasp type only).</p> <p>Conclusions</p> <p>The original outcome of this research is a novel controller empowered by vision and reasoning and capable of high-level analysis (i.e., determining object properties) and autonomous decision making (i.e., selecting the grasp type and size). The automatic control eases the burden from the user and, as a result, the user can concentrate on what he/she does, not on how he/she should do it. The tests showed that the performance of the controller was satisfactory and that the users were able to operate the system with minimal prior training.</p

Feedback-Mediated Upper Extremities Exercise: Increasing Patient Motivation in Poststroke Rehabilitation

Purpose. This proof-of-concept study investigated whether feedback-mediated exercise (FME) of the affected arm of hemiplegic patients increases patient motivation and promotes greater improvement of motor function, compared to no-feedback exercise (NFE). Method. We developed a feedback-mediated treatment that uses gaming scenarios and allows online and offline monitoring of both temporal and spatial characteristics of planar movements. Twenty poststroke hemiplegic inpatients, randomly assigned to the FME and NFE group, received therapy five days a week for three weeks. The outcome measures were evaluated from the following: (1) the modified drawing test (mDT), (2) received therapy time—RTT, and (3) intrinsic motivation inventory—IMI. Results. The FME group patients showed significantly higher improvement in the speed metric (P<0.01), and smoothness metric (P<0.01), as well as higher RTT (P<0.01). Significantly higher patient motivation is observed in the FME group (interest/enjoyment subscale (P<0.01) and perceived competence subscale (P<0.01)). Conclusion. Prolonged endurance in training and greater improvement in certain areas of motor function, as well as very high patient motivation and strong positive impressions about the treatment, suggest the positive effects of feedback-mediated treatment and its high level of acceptance by patients

New Way of Synthesis of Basic Bismuth Nitrate by Electrodeposition from Ethanol Solution: Characterization and Application for Removal of RB19 from Water

A new method of synthesis was developed for the preparation of sorbent basic bismuth nitrate [Bi6O5(OH)(3)](NO3)(5)center dot 2H(2)O (BBN-EtOH). This electrochemical method includes electrodeposition from an acidic Bi(III) solution in 96% ethanol at a constant current density of 150.0 mA cm(-2). Final product was obtained by thermal treatment at 200 degrees C. Characterization of BBN-EtOH was conducted by employing XRD, FTIR, SEM-EDX as well as BET, and its pI was also determined. The analysis showed that the material obtained is pure [Bi6O5(OH)(3)](NO3)(5)center dot 2H(2)O. Morphologically, it is composed of aggregates which were formed of several smaller particles of various shapes and sizes, some smaller than 100 nm. Electrochemically synthesized sorbent (BBN-EtOH) was used for the removal of the textile dye Reactive Blue 19 (RB19) from deionized water and model solution of river water, and it showed considerably superior sorption performance compared to other inorganic sorbents synthesized by conventional methods reported in the literature. Kinetic study suggests that the sorption process is both under reaction and diffusion control. Equilibrium of the sorption process was attained in several minutes, i.e., the sorption process is very fast. The sorption equilibrium data were well interpreted by the Langmuir, Sips and Brouers-Sotolongo isotherm. The maximum sorption performance was achieved at pH 2.0, and according to the Langmuir isotherm, it is 1344.99 mg g(-1)

Reslizumab versus placebo for poorly controlled, severe eosinophilic asthma: Meta-analysis

Background/Aim. Reslizumab is humanized monoclonal antibody produced by recombinant DNA technology which binds to circulating interleukin-5 (IL-5) and down-regulates the IL-5 signaling pathway. Reslizumab is indicated for the add-on maintenance treatment of patients 18 years and older with severe eosinophilic asthma phenotype whose symptoms were inadequately controlled with inhaled corticosteroids. The aim of this meta-analysis was to assess the efficacy and safety of reslizumab compared to placebo in patients suffering from inadequately controlled, moderateto- severe asthma with elevated blood eosinophil counts. Methods. Our meta-analysis was based on systematic search of literature and selection of high-quality evidence according to pre-set inclusion and exclusion criteria. The effects of reslizumab and placebo were summarized using Review Manager (RevMan) 5.3.5 and heterogeneity was assessed by the Cochrane Q test and I² values. Several types of bias were assessed and publication bias shown by Funnel plot and Egger’s regression. Results. The meta-analysis included 5 randomized, placebo-controlled clinical trials. Reslizumab 3.0 mg/kg produced substantial improvements in forced expiratory volume in 1. second (FEV 1) (mean difference 0.15 [0.10, 0.21]) and in forced vital capacity (FVC) (mean difference 0.21 [0.09, 0.32]) over the 15 or 16-week treatment period, substantial decrease versus placebo in Asthma Control Questionnaire (ACQ) score (mean difference -0.28 [-0.41, -0.16]), and substantial increase vs. placebo from baseline in Asthma Quality of Life Questionnaire (AQLQ) total score (mean difference 0.24 [0.06, 0.43]). Also, reslizumab 3.0 mg/kg caused less adverse events versus placebo (OR 0.67 [0.51, 0.88]), especially asthma worsening (OR 0.53 [0.36, 0.77]) or bronchitis (OR 0.42 [0.24, 0.74]). Conclusion. On the basis of published clinical trials reslizumab could be considered as an effective and safe therapeutic option for severe, poorly controlled eosinophilic asthma for the time being. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 175007

Effects of system parameters and inorganic salts on the photodecolourisation of textile dye Reactive Blue 19 by UV/H2O2 process

The photodecolourisation of textile dye Reactive Blue 19 (RB 19), an anionic anthraquinone dye of the reactive class, was investigated using UV radiation in the presence of H2O2 in a batch photo-reactor with low-pressure mercury lamps. The effects of the system parameters: initial pH, initial dye concentration, concentration of peroxide and radiation intensity, as well as the presence of salts, (NaCl, Na2SO4, NaNO3, NaH2PO4) on dye decolourisation was examined. Increasing the initial pH resulted in an increase in decolourisation efficiency. Results showed that with an increase of dye concentration from 10 to 100 mg∙ℓ–1, the efficiency of the process decreases. The highest decolourisation rates were noted at H2O2 concentrations of approximately 30 mmol∙ℓ–1. The increase of radiation intensity from 730 to 1 950 μW∙cm–2, linearly increases decolourisation efficiency. The inorganic ions investigated have inhibiting effects on RB 19 decolourisation by the UV/H2O2 process with inhibition intensities in the following order: H2PO4– > NO3– > SO42– > Cl–. This study has shown that the UV/H2O2 process is a promising technology for degradation of RB 19 in water and wastewater

Heterogeneous photocatalytic degradation of anthraquinone dye Reactive Blue 19: optimization, comparison between processes and identification of intermediate products

Treatment of textile wastewater using heterogeneous photocatalysis began in the the last decade and attracted the attention of researchers due to its versatile application. The variety of applications of TiO2 as a photocatalyst was due toits numerous positive properties, such as low operating temperature, biologically inert nature, low energy consumption, water insolubility, availability and photoactivity, low toxicity, high chemical stability, suitable flat band potential, narrow bandgap and the fact that it is environmentally benign. Heterogeneous UV-TiO2 photocatalysis is capable of removing organic pollutants from textile wastewater; this has been widely studied, with the technology also having been commercialized in many developing countries. Decolorization of anthraquinone dye Reactive Blue 19 (RB 19) by heterogeneous advanced oxidation processes TiO2/UV/H2O2, TiO2/UV/KBrO3 and TiO2/UV/(NH4)2S2O8 was studied under different conditions and in the presence of electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate ((NH4)2S2O8). Decolorization was very fast for all three processes, and complete dye decolorization was achieved in 10 min. The effect of various ions (Cl–, SO42– and HCO3–) on RB 19 decolorization was also studied. The optimal condition for the decolorization of the dye were determined to be: TiO2 concentration 1 g∙dm–3, electron acceptor concentration 30.0 mmol∙dm–3, dye concentration 50.0 mg∙dm–3, UV intensity 1 950 μW∙cm–2, at temperature 25 ± 0.5°C. In addition, experiments were performed and compared in three different matrices. In the surface water and dyebath effluent water, the removal efficiency for RB 19 was lower than that achieved in the deionized water because of the interference of complex constituents in the surface water and effluent. LC-MS analysis was carried out and the detected intermediates were compared with the previously published data for anthraquinone dyes