Exploring the Influence of Chemical Conditions on Nanoparticle Graphene Oxide Adsorption onto Clay Minerals.

High concentrations of graphene oxide (GO), a nanoparticle substance with rapid manufacturing development, have the ability to penetrate the soil surface down to the mineral-rich subsurface layers. The destiny and distribution of such an unusual sort of nanomaterial in the environment must therefore be fully understood. However, the way the chemistry of solutions impacts GO nanoparticle adsorption on clay minerals is still unclear. Here, the adsorption of GO on clay minerals (e.g., bentonite and kaolinite) was tested under various chemical conditions (e.g., GO concentration, soil pH, and cation valence). Non-linear Langmuir and Freundlich models have been applied to describe the adsorption isotherm by comparing the amount of adsorbed GO nanoparticle to the concentration at the equilibrium of the solution. Our results showed fondness for GO in bentonite and kaolinite under similar conditions, but the GO nanoparticle adsorption with bentonite was superior to kaolinite, mainly due to its higher surface area and surface charge. We also found that increasing the ionic strength and decreasing the pH increased the adsorption of GO nanoparticles to bentonite and kaolinite, mainly due to the interaction between these clay minerals and GO nanoparticles' surface oxygen functional groups. Experimental data fit well to the non-linear pseudo-second-order kinetic model of Freundlich. The model of the Freundlich isotherm was more fitting at a lower pH and higher ionic strength in the bentonite soil while the lowest R2 value of the Freundlich model was recorded at a higher pH and lower ionic strength in the kaolinite soil. These results improve our understanding of GO behavior in soils by revealing environmental factors influencing GO nanoparticle movement and transmission towards groundwater.

Inspiratory muscle training for recovered COVID-19 patients after weaning from mechanical ventilation: A pilot control clinical study.

BACKGROUND: To the best of our knowledge, no studies have evaluated the effects of inspiratory muscle training (IMT) on recovered COVID-19 patients after weaning from mechanical ventilation. Therefore, this study assessed the efficacy of IMT on recovered COVID-19 patients following mechanical ventilation. METHODS: Forty-two recovered COVID-19 patients (33 men and 9 women) weaned from mechanical ventilation with a mean age of 48.05 ±â€Š8.85 years were enrolled in this pilot control clinical study. Twenty-one patients were equipped to 2-week IMT (IMT group) and 21 matched peers were recruited as a control (control group). Forced vital capacity (FVC%), forced expiratory volume in 1 second (FEV1%), dyspnea severity index (DSI), quality of life (QOL), and six-minute walk test (6-MWT) were assessed initially before starting the study intervention and immediately after intervention. RESULTS: Significant interaction effects were observed in the IMT when compared to control group, FVC% (F = 5.31, P = .041, ηP2 = 0.13), FEV1% (F = 4.91, P = .043, ηP2 = 0.12), DSI (F = 4.56, P = .032, ηP2 = 0.15), QOL (F = 6.14, P = .021, ηP2 = 0.17), and 6-MWT (F = 9.34, P = .028, ηP2 = 0.16). Within-group analysis showed a significant improvement in the IMT group (FVC%, P = .047, FEV1%, P = .039, DSI, P = .001, QOL, P < .001, and 6-MWT, P < .001), whereas the control group displayed nonsignificant changes (P > .05). CONCLUSIONS: A 2-week IMT improves pulmonary functions, dyspnea, functional performance, and QOL in recovered intensive care unit (ICU) COVID-19 patients after consecutive weaning from mechanical ventilation. IMT program should be encouraged in the COVID-19 management protocol, specifically with ICU patients.