Nanomaterials providing sustained release profiles are highly desired for efficacious drug delivery. Advanced nanotechnologies are useful tools for creating elaborate nanostructure-based nanomaterials to achieve the designed functional performances. In this research, a modified coaxial electrospinning was explored to fabricate a novel core-sheath nanostructure (nanofibers F2), in which a sheath drug-free gliadin layer was successfully coated on the core ketoprofen (KET)-gliadin nanocomposite. A monolithic nanocomposite (nanofibers F1) that was generated through traditional blending electrospinning of core fluid was utilized as a control. Scanning electron microscopy demonstrated that both nanofibers F1 and F2 were linear. Transmission electron microscopy verified that nanofibers F2 featured a clear core-sheath nanostructure with a thin sheath layer about 25 nm, whereas their cores and nanofibers F1 were homogeneous KET-gliadin nanocomposites. X-ray diffraction patterns verified that, as a result of fine compatibility, KET was dispersed in gliadin in an amorphous state. In vitro dissolution tests demonstrated that the thin blank nanocoating in nanofibers F2 significantly modified drug release kinetics from a traditional exponential equation of nanofibers F1 to a zero-order controlled release model, linearly freeing 95.7 ± 4.7% of the loaded cargoes over a time period of 16 h.
Aiming at the three-dimensional defects detection of high-voltage cables joint, a method based on iterative residual fitting is proposed. The three-dimensional point cloud data was obtained by reconstructing the laser line projected onto the surface of the high-voltage cable joint. In order to remove noise generated by reconstruction which is located above or below the curve, a simple and effective strategy that the noise can be filtered by the gradient change in the neighborhood is adopted. Then a continuous iterative residual fitting method is proposed to effectively reduce the interference of the defect area on the curve fitting accuracy, thereby obtaining the accurate equation expression of the cable surface curve. By comparing the residual value of the high-voltage cable surface points relative to the fitting curve, the points of the defect area are marked. Finally three-dimensional defect area is extracted through segmentation and clustering. Experiments have verified the effectiveness of this method. Compared with the cylindrical fitting method, it can be seen that both the center deviation and the deviation in the length, width and height of extracted defects are better than the cylindrical fitting method. The recognition rate of concave and convex defects of the proposed method are 96.29% and 93.20% respectively .
Microplastics (MPs), a new type of pollutant, pose a significant threat to the environment at high concentrations. One of the primary sources of MPs in the ocean is river runoff, highlighting the need to investigate the spatial and temporal variations of MPs in rivers that flow into the sea, as well as their contributing factors. In this study, we analyzed MPs distribution and their influence factors in the Lincheng River, China. The Lincheng is the second largest river in Zhoushan island that directly flows into the ocean. MPs in the river water and sediments were detected during the wet season (July 2021), the dry season (November 2021) and the typhoon season (September 2021), and MPs were present in all reaches of the river. The abundance of MPs in the river was moderate compared to other studies, with the river water exhibiting a concentration of 15 ± 2.64 n/L and the sediment containing 318.24 ± 49.53 n/kg of MPs. In surface water, the most commonly found MP was blue man-made cellulose (CE), while the sediment contained mostly fragments of polypropylene (PP) and polypropylene polyethylene blends (PP + PE) in blue and green colors. The abundance of MPs showed significant seasonal differences, with higher abundance during the wet season compared to the dry season and typhoon period. Furthermore, local construction activities may contribute to higher MP abundance. To explore the influence factors of MPs, the Basin Development Index (BDI) was proposed, and a positive correlation between BDI and MP abundance was founded. This correlation indicates that the increase in land use for construction highly contributes to the MP pollution. In conclusion, future long-term monitoring of the abundance of MPs in the Lincheng River is necessary.
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