ABSTRACT
Objectives: While cervical proprioception deficit has been suggested as a contributing factor to clinical consequences of chronic non-specific neck pain (CNSNP), the effect of addressing such impairments on postural control strategies has remained unexplored. The aim of this study was to compare the response of the postural control system to alteration of sensory afferents in CNSNP with asymptomatic individuals. Furthermore, we examined whether proprioceptive training would yield superior outcomes to routine physiotherapy for improvement of postural control, pain and disability. Methods: Center of pressure (CoP) variables of sixty CNSNP patients equally distributed in any of the proprioception-specific or conventional physiotherapy groups and 30 asymptomatic participants were evaluated under four standing conditions:1) normal, 2) foam, 3) cervical extension/eyes open and 4) cervical extension/eyes closed standing. Results: CoP anteroposterior range and anteroposterior and mediolateral velocity in patients were significantly higher than the control group under condition 2 (P<0.05). Patients also demonstrated lower anteroposterior lyapunov exponent under conditions 2 and 4 (P<0.05). Both interventions significantly decreased anteroposterior range and anteroposterior velocity(P<0.05). Anteroposterior lyapunov exponent also increased under condition 2 (P<0.05).. After the interventions, CoP anteroposterior range and anteroposterior velocity were significantly lower in the proprioceptive exercise group than the conventional physiotherapy group (P<0.05). Anteroposterior lyapunov exponent was also significantly higher in the proprioceptive exercise group (P<0.05).This while there was no significant difference between these patients and control group participants in any of the CoP variables after intervention. Conclusion: Our results rejected the hypothesis that impaired neck proprioception in the presence of CNSNP is compensated by overweighting other sources of sensory afferent information. The findings also revealed that while proprioceptive exercises successfully returned postural strategies of CNSNP patients to those in asymptomatic participants, they do not add to clinical recovery of these patients.
ABSTRACT
Background: In recent years, the biosorption of heavy metals by Lactobacillus strains has received attention from researchers. We aimed to remove of heavy metals lead and cadmium from L. fermentum 6b exopolysaccharide in 2021. Methods: Extracellular exopolysaccharide was first extracted from selected probiotic strain, and then the effect of variables such as pH, the extracted exopolysaccharide adsorbent dose, contact time, heavy metal concentration, and temperature on the adsorption rate was investigated. The adsorption isotherms of Langmuir and Freundlich were also examined. Pseudo-first and pseudo-second-order kinetics equations were also investigated for the desired surface adsorption. Results: The adsorption process at pH=6.5, contact time=80 min, pollutant concentration=100 mg.L-1, adsorbent dose (extracted exopolysaccharide) =1500 mg.L-1, temperature=35°C for cadmium; pH= 6, contact time=60 min, contaminant concentration of 100 mg.L-1, adsorbent dose (extracted exopolysaccharide) =1500 mg.L-1 temperature=of 35 °C for lead had optimum condition. The adsorption process corresponded to Freundlich isotherm with R2=0.958 and R2=0.988, and pseudo-second-order kinetic with R2=0.99 and R2=0.85 for cadmium and lead, respectively. Conclusion: The exopolysaccharide extracted from L. fermentum 6b isolate can have an acceptable removal potential for lead and cadmium heavy metals.
