Intraoperative use of low-dose dexmedetomidine for the prevention of emergence agitation following general anaesthesia in elderly patients: a randomized controlled trial.

OBJECTIVE: To clarify the effect of an intraoperative low-dose dexmedetomidine infusion on emergence agitation following general anaesthesia in elderly patients. METHODS: Eighty elderly patients (> 64-years-old) following elective general anaesthesia for radical cancer surgeries were randomly allocated into two groups (n = 40 each): the dexmedetomidine group (Group D) and the normal saline group (Group C). Anaesthesia was maintained with continuous intravenous infusion of dexmedetomidine at - 0.2 µg kg-1 h-1 in Group D, and an equal volume of normal saline (0.5 ml kg-1 h-1) was given in Group C. All patients were observed for 30 min in the post-anaesthesia care unit (PACU), AFPS and NRS were recorded every 2 min, and the total doses of nalbuphine and fentanyl were calculated in the PACU. MAP and HR were recorded at the time of 10 min (T1), 20 min (T2), 30 min (T3) after dexmedetomidine or saline pumping, and before extubation (T4), immediately after extubation (T5), and 5 min after extubation (T6). We also documented some durations, including anaesthesia duration (D1), surgery duration (D2), duration from the end of surgery to extubation (D3), and emergence agitation duration (D4). RESULTS: The MAP in Group C was significantly higher than that in Group D (P < 0.05), and there were no significant changes between the two groups in HR and MAP within each time point and D1, D2, D3, and D4. The incidence of agitation, NRS score and total dose of nalbuphine and fentanyl were all lower in Group D than in Group C (P < 0.05). CONCLUSION: An intraoperative low-dose dexmedetomidine continuous infusion can reduce emergence agitation following general anaesthesia in elderly patients (> 64-years-old), remain stable in terms of haemodynamics, and not lead to delays in anaesthesia recovery time and extubation time.

Micro-bubbles enhanced removal of diesel oil from the contaminated soil in washing/flushing with surfactant and additives.

Diesel removal of contaminated soil by washing/flushing was enhanced with micro-bubbles and selected surfactants based on their solubilization properties and decontamination capacities. The influencing factors were studied to aim for increasing washing/flushing efficacy. The mixture solution of saponin and cyclodextrin increased the removal efficiency significantly compared to the single-agent solution flushing with an increasing range of 20%-31%. Meanwhile, micro-bubble enhancement increased over 20% of the diesel removal for the sandy soil flushing. As the flushing process may cause soil eroded, the TDS and soil solute in flushing solution were measured to evaluate the circulation time. The 90 min flushing time ensured the cleaning goal and reserved the soil solute by circulation flushing. The soil solute, especially the electron acceptor (NO3-) , was remained in the soil, which was highly demanded for residual diesel biodegradation of loam soil. It is concluded that mixed agents, circulation of flushing solution, and micro-bubbles increased the diesel removal, and the circulation flushing could be very promising in practical applications.

Simultaneously enhanced surfactant flushing of diesel contaminated soil column and qualified emission of effluent.

Seven surfactants were selected as candidate agents for in situ soil column flushing. Column flushing lacks the interaction between surfactants and contaminants, so efficiency is not easy to improve. Microbubbles generated in situ may adhere to the contaminant diesel. Thereafter, the bubbles were mobilized to lift the multi-system oil to the top layer. This process must be attributed to the increased column flushing efficiency of diesel removal. Compared with a single solution, using randomly methylated beta-cyclodextrin (RAMEB) and microbubble enhancement, the diesel removal of column flushing increased by 30.7%. Compared with the existing conditions (5.25 × 10-4 cm s-1), the hydraulic conductivity of loam soil (3.74 × 10-3 cm s-1) increased by 7.1 times after the continued operation of the two processes. The oil layer was collected for further reuse. After three treatments, the effluent for the RAMEB was more than 85%. The collected effluent was treated with a synthetic absorbent and then qualifiedly discharged with a TOC value of only 2.6 mg L-1. By combining surfactant flushing with microbubbles and other equipment, not only can the reaction time be effectively saved, but organic pollutants could be concentrated and reused in the soil, so no additional treatment was required.

Enhancement of auxiliary agent for washing efficiency of diesel contaminated soil with surfactants.

We used five types of surfactants assisted with sodium salts, including sodium tartrate (ST), sodium chloride (SC), and humic acid sodium (HAS) as auxiliary agents for soil washing to remove diesel from contaminated soil. Decontamination enhancement of diesel polluted soil washing with biosurfactant and H2O2 was examined, which showed higher effectiveness for newly contaminated soil. An increase in temperature and sodium salt addition exhibited a profound enhancement in diesel removal from aged contaminated soils. Compared to ST and SC, HAS exhibited a higher removal efficiency with saponin washing for aged diesel contaminated soil by lowering surface tension, shifting zeta potential, and increasing the number of micelles. Phytotoxicity experiments showed no significant inhibition of germination of lettuce, arugula, and cucumber with 0.2 g L-1 saponin incubation. Conversely, there was a promotion on the root extension of lettuce and cucumber except for arugula. Similarly, the addition of 2% HAS (wight of saponin) improved on root growth of lettuce, arugula, and cucumber, increasing by 25%, 5%, and 22% at the period of 14 d, respectively. Because of excellent removal efficiency and non-toxicity, enhanced wash with saponin and HAS might be considered in the future design of full-scale remediation processes of diesel contaminated soil.

Enzyme-catalysed biodegradation of carbon dots follows sequential oxidation in a time dependent manner.

Carbon dots (CDs) have recently garnered significant attention owing to their excellent luminescence properties, thereby demonstrating a variety of applications in in vitro and in vivo imaging. Understanding the long-term metabolic fate of these agents in a biological environment is the focus of this work. Here we show that the CDs undergo peroxide catalysed degradation in the presence of lipase. Our results indicate that differently charged CD species exhibit unique degradation kinetics upon being subjected to enzyme oxidation. Furthermore, this decomposition correlates with the relative accessibility of the enzymatic molecule. Using multiple physico-chemical characterization studies and molecular modelling, we confirmed the interaction of passivating surface abundant molecules with the enzyme. Finally, we have identified hydroxymethyl furfural as a metabolic by-product of the CDs used here. Our results indicate the possibility and a likely mechanism for complete CD degradation in living systems that can pave the way for a variety of biomedical applications.

[Strengthening Effects of Sodium Salts on Washing Kerosene Contaminated Soil with Surfactants].

The impact of sodium salt on kerosene contaminated soil washing with surfactants was investigated. The results indicated that sodium silicate greatly enhanced the washing efficiency of SDS. Sodium tartrate can largely enhance the washing efficiency of SDBS and Brij35. Sodium salts can enhance the washing efficiency on kerosene contaminated with TX-100. No significant differences were observed between different sodium salts. Sodium salt of humic acid and sodium silicate had similar enhancement on kerosene contaminated soil washing with saponin. Sodium humate can be a better choice since its application can also improve soil quality. The enhancement of sodium silicate on kerosene contaminated soil washing with Tw-80 increased with the increase of Tw-80 dosage. However, the impact of sodium chloride and sodium tartrate was opposite to sodium silicate. Sodium salts can reduce surface tension and critical micelle concentration of ionic surfactants to enhance the washing. Sodium salts can also reduce re-adsorption of oil to soil with nonionic surfactants to enhance the washing. Kerosene contamination can increase the contact angle of soil, which indicated the increase of hydrophilicity of soil. Washing with surfactants can reduce the hydrophilicitiy of soil according to contact angle measurement, which indicated that kerosene contaminated soil remediation with surfactant can also benefit nutrient and water transportation in the contaminated soil.