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1.
Turk J Med Sci ; 49(4): 1054-1067, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31293146

RESUMO

Background/aim: This study aims to explore the mirror neuron system (MNS) involvement using mu (8­12 Hz)/beta (15­25 Hz) band suppression in an action observation-execution paradigm. Materials and methods: Electrophysiological (EEG) data from 16 electrodes were recorded while 8 participants observed video clips of a hand squeezing a spring. Specifically, the effect of anticipated execution on observation was studied. For this purpose, a fully actuated finger exoskeleton robot was utilized to synchronize observation and execution and to control the execution condition for the partici-pants. Anticipatory effect was created with a randomized robot accompany session. Results: The results showed that the observational condition (with or without anticipation) interacted with hemisphere at central chan-nels near somatosensory cortex. Additionally, we explored the response of MNS on the kinetics features of visual stimuli (hard or soft spring). Conclusion: he results showed an interaction effect of kinetics features and hemisphere at frontal channels corresponding nearly to the ventral premotor cortex area of the brain. The activation of mirror neurons in this area plays a crucial role in observational learning. Based on our results, we propose that specific type of visual stimuli can be combined with the functional abilities of the MNS in the ac-tion observation based treatment of hand motor dysfunction of stroke patients to have a positive additional impact.


Assuntos
Antecipação Psicológica/fisiologia , Exoesqueleto Energizado , Aprendizagem/fisiologia , Neurônios-Espelho/fisiologia , Estimulação Luminosa , Adulto , Eletroencefalografia , Humanos , Masculino , Reabilitação do Acidente Vascular Cerebral , Gravação de Videoteipe
2.
Exp Brain Res ; 236(2): 497-503, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29230518

RESUMO

This study aimed to explore the relationship between action observation (AO)-related corticomotor excitability changes and phases of observed action and to explore the effects of pure AO and concurrent AO and motor imagery (MI) state on corticomotor excitability using TMS. It was also investigated whether the mirror neuron system activity is muscle-specific. Fourteen healthy volunteers were enrolled in the study. EMG recordings were taken from the right first dorsal interosseous and the abductor digiti minimi muscles. There was a significant main effect of TMS timing (after the beginning of the movement, at the beginning of motor output state, and during black screen) on the mean motor evoked potential (MEP) amplitude. Mean MEP amplitudes for AO combined with MI were significantly higher than pure AO session. There was a significant interaction between session and TMS timing. There was no significant main effect of muscle on MEP amplitude. The results indicate that corticomotor excitability is modulated by different phases of the observed motor movement and this modulation is not muscle-specific. Simultaneous MI and AO enhance corticomotor excitability significantly compared to pure AO.


Assuntos
Potencial Evocado Motor/fisiologia , Retroalimentação Sensorial/fisiologia , Imaginação/fisiologia , Neurônios-Espelho/fisiologia , Córtex Motor/fisiologia , Análise de Variância , Eletromiografia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Estimulação Magnética Transcraniana
3.
Toxics ; 11(11)2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37999590

RESUMO

In light of the global health crisis triggered by the COVID-19 pandemic, numerous experts have deemed the utilization of hand sanitizers imperative as a precautionary measure against the virus. Consequently, the demand for hand sanitizers has experienced a substantial surge. Since the beginning of 2020, the utilization of alcohol-free hand sanitizers has been increasingly favored due to the potential risks associated with alcohol poisoning, flammability, as well as the adverse effects on skin lipid dissolution, dehydration, and sebum reduction, which can lead to severe cases of eczema and norovirus infections. In this study, we developed an aqueous hand sanitizer that does not contain alcohol. The sanitizer consists of naturally occurring, food-grade organic acids, including lactic, citric, and azelaic acids. Additionally, food-grade ammonium sulfate and a small amount of povidone-iodine (PVPI) were included in the formulation to create a synergistic and potent antibacterial effect. The effectiveness of the hand sanitizer was evaluated against four common foodborne pathogens, namely Clostridium botulinum, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus, via in vitro testing. The organic acids exhibited a synergistic inhibitory function, resulting in a 3-log reduction in CFU/mL. Furthermore, the presence of povidone-iodine and ammonium sulfate enhanced their antibacterial effect, leading to a 4-log reduction in CFU/mL. The hand sanitizer solution remained stable even after 60 days of storage. During this period, the detection of additional triiodide (I3-) ions occurred, which have the ability to release broad-spectrum molecular iodine upon penetrating the cell walls. This alcohol-free hand sanitizer may offer extended protection and is anticipated to be gentle on the skin. This is attributed to the presence of citric and lactic acids, which possess cosmetic properties that soften and smoothen the skin, along with antioxidant properties.

4.
Polymers (Basel) ; 14(6)2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35335530

RESUMO

Waterborne polyurethane dispersions can be designed to generate highly functional and environmentally friendly polymer systems. The use of water as the main dispersion medium is very advantageous for the environment and the introduction of linear and aliphatic polyols such as polyether and polyesters in the formulations can make them highly biocompatible and susceptible to biodegradation. In this study, we fabricated biodegradable, flexible and transparent plastic films by hybridizing a waterborne aliphatic polyester polyurethane (PU) suspension with polyvinylpyrrolidone (PVP) using mechanical homogenization in water. Films were cast containing different concentrations of PVP. The hybrids containing 50 wt.% PVP (PU/PVP_50/50) were hydrophobic, stretchable, highly transparent and ductile beyond 100% strain compared to highly brittle PVP. The mechanical properties of the PU/PVP_50/50 film remained stable after repeated immersion wet-dry cycles, each lasting 2 days, and the dried films recovered their mechanical properties after each cycle. Based on a 28-day biochemical oxygen demand (BOD) test, the hybrid PU/PVP_50/50 film underwent extensive biodegradation. This simple but effective process can be very suitable in producing biodegradable ductile films with very good transparency that can serve a number of applications such as agricultural mulches, food and pharmaceutical packaging and biomedical field.

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