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

Removal of cationic pollutants from water by xanthated corn cob: optimization, kinetics, thermodynamics, and prediction of purification process

The removal of Cr(III) ions and methylene blue (MB) from aqueous solutions by xanthated corn cob (xCC) in batch conditions was investigated. The sorption capacity of xCC strongly depended of the pH, and increase when the pH rises. The kinetics was well fitted by pseudo-second order and Chrastil’s model. Sorption of Cr(III) ions and MB on xCC was rapid during the first 20 min of contact time and, thereafter, the biosorption rate decrease gradually until reaching equilibrium. The maximum sorption capacity of 17.13 and 83.89 mg g-1 for Cr(III) ions and MB, respectively was obtained at 40 °C, pH 5 and sorbent dose 4 g dm-3 for removal of Cr(III) ions and 1 g dm-3 for removal of MB. The prediction of purification process was successfully carried out and the verification of theoretically calculated amounts of sorbent was confirmed by using packed-bed column laboratory system with recirculation of the aqueous phase. The wastewater from chrome plating industry was successfully purified, i.e. after 40 min concentration of Cr(III) ions was decreased lower than 0.1 mg dm-3. Also, removal of MB from the river water was successfully carried out and after 40 min removal efficiency was about 94 %

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

Praćenje fotodegradacije nitrolakova FTIR spektroskopijom

The FTIR spectroscopy has been employed in this research work to monitor the process of nitrodope photodegradation, by measuring surfaces of bands typical of a nitro group. Nitric esters are subject to degradation, which is reflected on a quantitative ratio of the surfaces of the IR bands that originate from the nitric ester. The obtained results show that the length of the UV rays activity on the samples over time intervals of 240, 480 and 960 min. directly affects the spectrum appearance of the same sample before and after the radiation. The longer the UV rays activity time and the larger a mass proportion of nitrocellulose in the nitrodope is, the smaller the bands surface becomes i.e. the degree of degradation is higher. To confirm the degradation of nitrodope the degree of reticulation has also been examined by determining the König hardness.U radu je korišćena FTIR spektroskopija za praćenje procesa fotodegradacije nitrolakova, merenjem površina traka koje su karakteristične za nitro grupu. Nitratni estri podležu degradaciji što se odražava na kvantitativni odnos površina IR traka koje potiču od nitratnog estra. Dobijeni rezultati pokazuju da dužina dejstva UV zraka na uzorke u vremenskim intervalima od 240, 480 i 960 min., direktno utiče na izgled spektra istog uzorka pre i posle zračenja. Što je duže vreme dejstva UV zraka kao i maseni udeo nitroceluloze u nitrolaku površina traka se sve više smanjuje tj.stepen degradacije je veći. Za potvrdu degradacije nitrolakova praćen je i stepen umreženosti određivanjem tvrdoće po König-u

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

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)

A New Photocatalyst Bismuth Oxo Citrate: Synthesis, Characterization, and Photocatalytic Performance

A new photocatalyst bismuth oxo citrate was synthesized by facile precipitation process with calcination at 200 8C. The photocatalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fouriertransform infrared (FTIR) spectroscopy, N2 sorptometry, and elemental analysis. Morphologically, it is composed of polyhedral particles with different, irregular shapes and sizes. The specific surface area (SSA) of the photocatalyst was 8.92 m2 g-1. It showed very good photocatalytic performance and reusability. Total decolorization of Reactive Blue 19 (RB19) was achieved in less than 10 minutes, which is much faster in comparison with TiO2 P25. Also, bismuth oxo citrate showed higher photocatalytic activity than other photocatalysts based on bismuth compounds reported by other authors. Optimal photocatalysis parameters were pH 2 and photocatalyst dose of 250 mg dm-3. The decolorization rate was found to decrease as initial dye concentration increased. The photocatalytic data best fitted to L-H kinetic model with pseudo-first order reaction rate. Chrastil diffusion model showed that diffusion has not influence on the process. Water Environ. Res., 90, 719 (2018). © 2018 Water Environment Federation

Application of new biosorbent based on chemicaly modified Lagenaria vulgaris shell for the removal of copper(II) from aqueous solutions: Effects of operational parameters

In present study a low cost biosorbent derived from Lagenaria vulgaris plant by xanthation, was tested for its ability to remove copper from aqueous solution. The effect of contact time, initial pH, initial concentration of copper(II) ions and adsorbent dosage on the removal efficiency were studied in a batch process mode. The optimal pH for investigated metal was 5. A dosage of 4 g dm-3 of xanthated Lagenaria vulgaris biosorbent (xLVB) was found to be effective for maximum uptake of copper(II). The kinetic of sorption of metal was fast, reaching at equilibrium in 50 min. The kinetic data were found to follow closely the pseudo-second-order model. The adsorption equilibrium was described well by the Langmuir isotherm model with maximum adsorption capacity of 23.18 mg g-1 copper(II) ions on xLVB. The presence of sulfur groups on xLVB were identified by FTIR spectroscopic study. Copper removal efficiency was achieved at 81.35% from copper plating industry wastevater