Removal Of Challenge Research Articles

Sustainable large-scale Fe3O4/carbon for enhanced polystyrene nanoplastics removal through magnetic adsorption coagulation

The omnipresence of nanoplastics in natural water sources raises significant environmental and health concerns due to their challenging removal and potential to transport harmful pollutants. These particles pose threats to terrestrial and aquatic ecosystems, as well as human health, inducing inflammation and oxidative stress. In response, this study focused on an innovative Fe3O4/C nano-adsorbent, derived from discarded printer cartridge toner, for tackling the removal of polystyrene nanoplastics (PS-NPs) through magnetic adsorption coagulation (MAC) with polyaluminum chloride (PACl) as a coagulant. Extensive experimentation achieved a remarkable 99 % removal efficiency at a desirability function value of 0.868 under optimum conditions (pH = 8, adsorbent dosage 2.5 mg, contact time 2 min, PACl concentration 17.5 mg/L, PS-NPs concentration 75 mg/L) with an R2 = 0.9997, a CV% = 0.730 and an Adeq Precision = 122.837. The dominant removal mechanism involved adsorption bridging and electrostatic interaction between PS-NPs and Fe3O4/C in the presence of PACl. Findings covered adsorption kinetics, isotherms, and thermodynamics, adhering to the pseudo-second-order model (R2 = 0.996), Langmuir (R2 = 0.9912) isotherm and negative value of ΔG° (−8.899) as an endothermic adsorption process. The results demonstrated a maximum adsorption capacity of 523 mg/g, showcasing the effectiveness of the approach. Furthermore, the Fe3O4/C material exhibited robust reusability and stability, owing to its magnetite properties. The primary goal was to engineer a magnetic recoverable nano-adsorbent from discarded toner, contributing to cost reduction, streamlined coagulation processes, reduced coagulant consumption, and significantly improved micro/nanoplastics removal.

Surgical Detachment of the Anterior Hyaloid Membrane From the Posterior Lens Capsule

Purpose: To describe 2 techniques facilitating the potentially challenging removal of the anterior hyaloid during phakic pars plana vitrectomy. Methods: Observational surgical series describing the 2 techniques. The hydrodissection technique applies an injection of balanced salt solution into the anterior chamber to displace the anterior hyaloid posteriorly for facile removal. The bubble technique is a novel method that utilizes air bubbles to visualize the anterior vitreous, allowing closer placement of the vitrectomy cutter to facilitate anterior hyaloid removal. Results: Both techniques were successful for the safe, efficient removal of the anterior vitreous. Conclusion: Removal of the anterior vitreous in a phakic patient is a difficult maneuver which may lead to potential damage to the lens. The hydrodissection and bubble techniques may be used to efficiently and safely remove the anterior vitreous.

Vigilance Enhancement using Challenge Integration in a Naturalistic Surveillance Task

Vigilance Enhancement using Challenge Integration in a Naturalistic Surveillance Task

Vocal Folds Detect Ionic Perturbations on the Luminal Surface: An In Vitro Investigation

The homeostasis of fluid bathing the luminal surface of the vocal folds is important for phonation and laryngeal defense. Dehydration of the respiratory tract during mouth breathing can perturb the concentration of sodium and chloride ions in surface fluid. Exposure to dry air also increases the osmolarity of airway surface fluid. We hypothesized that viable vocal fold epithelium would detect changes in the ionic and osmotic composition of fluid on the luminal surface. Therefore, we examined bioelectric responses of vocal folds exposed to physiologically real, luminal ionic and osmotic challenges in vitro. The study used randomized factorial design with experimental and sham control groups. Fifty native ovine vocal folds were exposed to five challenges (ionic, osmotic, combined ionic-osmotic, and sham) on the luminal surface. Bioelectric measures of potential difference (PD), short-circuit current (I(SC)), and tissue resistance were assessed at prechallenge baseline, during challenge, and after removal of challenge. Ionic and combined ionic-osmotic challenges reduced PD and I(SC) (P<0.01). These reductions depended on the nature of the ionic challenge, were observed within 10 minutes, lasted for the duration of exposure, and were reversible after removal of the challenge. Conversely, sham or osmotic challenge did not alter bioelectric parameters over time (P>0.05). Viable ovine vocal fold epithelia detect ionic perturbations to the luminal surface. This sensitivity to luminal ionic challenge may be necessary to maintain the homeostasis of surface fluid.