Search

The aim of this study was to develop a new nicotine transdermal patch: S‐(‐)‐Nicotine‐loaded nano flexible liposome hydrogel patch (S‐(‐)‐Nicotine‐NFL‐HGP), which combined liposome and hydrogel to achieve the long‐lasting and sustained release of S‐(‐)‐Nicotine for the treatment of nicotine withdrawal syndrome (NWS). The S‐(‐)‐Nicotine nanoscale flexible liposomes (S‐(‐)‐Nicotine‐NFL) were prepared using the thin film hydration method, and then combined with a three‐dimensional structured hydrogel to prepare S‐(‐)‐Nicotine‐NFL‐HGP. The initial bond strength (IBS) was (18 ± 2) s, the lasting bond strength (EBS) was (23.5 ± 3.4) s, and the appearance was pale yellow. The cumulative release rate of the patch was 64.8% within 48 h and the Higuchi equation of the drug release process was y = 9.47x1/2−1.13 (R2 = 0.99412). The cumulative transmittance per unit area of the patch after 48 h was (1047 ± 25.0) µg/cm2 and the dermal retention was (35.1 ± 4.2) µg/cm2. The Higuchi equation of the transdermal drug process showed the highest fit in the transdermal experiments with a long‐lasting and sustained release of S‐(‐)‐Nicotine. Stability study results showed that the IBS, EBS, appearance, and the performance of drug release of the patch were almost unchanged within 90 days, which had excellent stability. The patch prepared in this study has potential application prospects. [ABSTRACT FROM AUTHOR]

The ash deposition is a general problem that needs to be solved effectively for the rotary air preheater of the coal-fired boiler. Taking the rotary air preheater of a 600 MW power station as the object, the mesh model of the flue gas side of the air preheater, considering the influences of steam soot blowing, is established using the Gambit 2.4.6 software. Based on the SIMPLE algorithm, the velocity field and the temperature field in the air preheater under varied working conditions are simulated using the software of Ansys Fluent 2021R1, and the influences of the boiler load, the operation parameters of the steam soot blower, and the running and outage of the soot blower on the flue gas velocity distribution in the depth direction of the corrugated plates, the soot-blowing coverage area, the inlet flue gas velocity, and the inlet flue gas temperature of the corrugated plates are analyzed. Under the base working condition, the flue gas velocity on the axis of the steam nozzle first decreases rapidly with increasing the corrugated plate depth (Z < 1.0 m), and then it decreases slowly with an almost equal slope. The longitudinal flue gas velocity has a positive correlation with the boiler load. The longitudinal flue gas velocity obviously decreases when the boiler load is decreased, and its reduction increases as the corrugated plate depth increases. It is one reason that the ash deposition is prone to occur on the cold end surface of corrugated plates under the condition of low boiler load. The longitudinal flue gas velocity increases with the soot-blowing steam velocity increasing when the corrugated plate depth is less than 1.5 m, but after that, it is almost not affected by the change in soot-blowing steam velocity. The soot-blowing coverage area has a negative correlation with the boiler load but a slight positive correlation with the steam velocity of the soot blower on the whole. The inlet flue gas velocity of the corrugated plates has a positive correlation with the boiler load and the inlet steam velocity of the soot blower. The average inlet flue gas velocity decreases by 21.7% when the boiler load is reduced by 50%. For every 5 m/s variation in the inlet steam velocity, the inlet flue gas velocity changes by about 10–14% whether the steam soot blower is put into operation or not, which has an obvious effect on the inlet gas velocity of the corrugated plates. The inlet flue gas temperature of the corrugated plates is, respectively, positively correlated with the boiler load and the inlet steam temperature of the soot blower. When the boiler load is reduced from 100% BMCR to 50% BMCR, the average inlet flue gas temperature of the corrugated plates is reduced by 44.2 K; however, when the soot-blowing steam temperature varies by 20 K, the average inlet flue gas temperature of the corrugated plates varies by only about 1.8 K. It means that it is difficult to enhance the cold end flue gas temperature of the corrugated plates only by raising the soot-blowing steam temperature at low boiler load. Adding a soot blower using high-temperature steam or hot air at the outlet of the corrugated plates may be an option to solve the ash deposition of the corrugated plates. [ABSTRACT FROM AUTHOR]

In this study, a novel drug delivery system (MSN-PEG-Hypericin) was successfully fabricated using tetraethyl orthosilicate and 3-aminopropyltriethoxysilane as raw materials, and the PEGylation of the prepared aminated mesoporous silica and grafting of hypericin onto the carrier were further conducted to obtain MSN-PEG-Hypericin. The successful preparation of MSN-PEG-Hypericin was characterized by several physical-chemical techniques. Furthermore, the MSN-PEG-Hypericin system increased the ability of hypericin to generate reactive oxygen species (ROS) in vitro. The cytotoxicity assay and hemolysis analysis showed that MSN-PEG-Hypericin had good biocompatibility. For antibacterial studies, the irradiation time and incubation time of photodynamic therapy (PDT) for S. aureus and E. coli were respectively 8 min and 8 h, and the concentrations of hypericin were 2.5 and 5 μg/mL. The result of triphenyl tetrazolium chloride assay indicated that MSN-PEG-Hypericin had stronger photodynamic antibacterial activity than free hypericin, and S. aureus was more sensitive to PDT than E. coli, which was related to their cell structural differences. The antibacterial mechanism study indicated that the generated ROS could destroy the bacterial structures and cause bacterial death due to the leakage of the contents. The MSN-PEG-Hypericin system prepared in this study had potential application prospects in the antibacterial field. [ABSTRACT FROM AUTHOR]

Given the strong coupling relationship between the Seebeck coefficient and electrical conductivity, achieving a significant increase in the thermoelectric power factor (PF) remains a formidable challenge. Previous studies have demonstrated that the ErAs:InGaAs system has the potential to leverage the energy filtering (EF) effect to enhance the Seebeck coefficient while maintaining high electron concentrations. Here, we present a method that significantly enhances the thermoelectric PF of InGaAs through the dual effects of quantum confinement and EF effects. Density Functional Theory calculations further demonstrate that the alterations in the ErAs band structure induce the EF effect. The results show that the ErAs quantum dots:In0.53Ga0.47As composite films exhibit high electrical conductivity and high Seebeck coefficient in the intermediate temperature range, resulting in a fivefold increase in the PF at 515 K. Our research presents a prospective approach to leveraging the combined effects for the advancement of high-performance thermoelectric materials. [ABSTRACT FROM AUTHOR]