Tissue engineering technology provides a promising approach for cartilage repair, and in this strategy, scaffolds play a pivotal role in directing cartilage regeneration. Fish collagen (FC) is currently considered an alternative source of mammalian collagen (MC) for tissue engineering due to its excellent biocompatibility, suitable biodegradability, inert immunogenicity, rich sources, low price and lack of risk for the transmission of zoonosis. Here, we fabricated three types of electrospun nanofibrous membranes composed of FC and polycaprolactone (PCL) with three different FC/PCL ratios (9/1, 7/3, 5/5) and investigated the feasibility of using the membranes with chondrocytes in cartilage regeneration. Our results demonstrated that increases in the FC content were associated with improvements in biodegradability, absorption, and cell adhesion capacity, but weaker mechanical properties. In addition, all three nanofibrous membranes showed satisfactory biocompatibility as evidenced by supporting chondrocyte proliferation and cartilage formation in vitro. Furthermore, all three membranes seeded with chondrocytes formed mature cartilage-like tissue after 8 weeks of in vivo culture, but satisfactory homogeneous cartilage regeneration was only achieved with the F9P1 group. The current results demonstrated that the electrospun FC/PCL membrane is a promising scaffold for cartilage regeneration and that the F9P1 group might represent a relatively suitable ratio. The research models established in the current study provide detailed information for the regeneration of cartilage and other tissue based on electrospun FC/PCL membranes.
Functional hydrogel is becoming a frequently used material in various fields, especially in biological and medical applications. In order to overcome the barriers of low uniformity of structure and lack of energy dissipation effect in common hydrogel, in this work a strategy of doping plasmonic H x MoO 3 quantum dots into PNIPAM (poly (N‐isopropylacrylamide)) hydrogel to proceed its multifunctionalization is developed. This quantum dots‐induced tactic could effectuate the enhancement of photothermal conversion, mechanical property, adhesion, and self‐healing performance simultaneously. In particular, for adhesion performance, the toughness value could be elevated to over 2500 J m −2 efficiently. Further, the enhancement mechanism behind the extraordinary adhesion performance is studied, and it can be contributed to the synergistic effect of pore structure regulation and abundant hydrogen bond, which are both beneficial to the interaction between composite hydrogel and solid surface. Subsequently, based on its extraordinary adhesion and self‐healing performance, the applicability of H x MoO 3 /PNIPAM hydrogel as a MØ growth substrate is investigated on wound dressing, and the experimental result demonstrates its excellent MØ growth‐promoting activity.
Interfacial solar-driven evaporation technology shows great potential in the field of industrial seawater desalination, and the development of efficient and low-cost evaporation materials is key to achieving large-scale applications. Hydrogels are considered to be promising candidates; however, conventional hydrogel-based interfacial solar evaporators have difficulty in simultaneously meeting multiple requirements, including a high evaporation rate, salt resistance, and good mechanical properties. In this study, a Janus sponge-like hydrogel solar evaporator (CPAS) with excellent comprehensive performance was successfully constructed. The introduction of biomass agar (AG) into the polyvinyl alcohol (PVA) hydrogel backbone reduced the enthalpy of water evaporation, optimized the pore structure, and improved the mechanical properties. Meanwhile, by introducing hydrophobic fumed nano-silica aerogel (SA) and a synergistic foaming-crosslinking process, the hydrogel spontaneously formed a Janus structure with a hydrophobic surface and hydrophilic bottom properties. Based on the reduction of the evaporation enthalpy and the modulation of the pore structure, the CPAS evaporation rate reached 3.56 kg m-2 h-1 under one sun illumination. Most importantly, owing to the hydrophobic top surface and 3D-interconnected porous channels, the evaporator could work stably in high concentrations of salt-water (25 wt%), showing strong salt resistance. Efficient water evaporation, excellent salt resistance, scalable preparation processes, and low-cost raw materials make CPAS extremely promising for practical applications.
This paper proposes an approach based on graph isomorphism to find the correspondence in relational matching. We describe a pseudo-automorphism group as Pseudo-aut (G) of a graph G, which is a set of all pseudo-automorphisms of G. We discuss some properties of the Pseudo-aut(C n ) and the relationships between various elements, establish the relationship between the pseudo-isomorphic and the perfect matching. From these we reach some important conclusions: the Petersen graph is a special element of the Pseudo-aut(C 5 ); the composition of the Petersen graph is just one of its origins; there exists a Hamiltonian graph of order 12, which is 3-connected, 3-regular, non-planar, non-bipartite, and its girth is 5.
By using finite element method (FEM), nanofibers' deposition behavior including the orientation and alignment of nanofibers that are approaching to fiber collectors was simulated and systematically investigated in term of the effects of electrostatic field. Based on the simulation results, we have experimentally demonstrated that Poly (epsiv-caprolactrone) (PCL) nanofibers with various disired patterns and ordered architectures can be prepared using predesigned fiber collectors. When cultured with mouse osteoblastic cell line (MC3T3-E1), it was found that the cells grew and elongated along the fiber orientation directions, and the results cellular organization and distribution mimicked the topological structures of the PCL nanofiber scaffolds. These results indicated that electrospun nanofiber scaffolds with tailored architechtures and patterns hold potential for engineering functional tissues or organs, where an ordered cellular organization is essential.
The Yangtze River model was constructed to study the flood evolution in the middle and lower reaches of Yangtze River. To automatically measure and dynamically track the water level in the river model, water level meter was designed. An optical scale with 1um resolution was used as a position detection sensor; the optical scale output signals were processed and then were counted by the reversible counter T2 of the AT89S52 microcontroller. Water surface detection probe was designed based on the water with low electrical conductivity, and the probe was fixed on the sliding rule of the optical scale; a stepper motor was used to drive the probe slid up and down. When probe downward contacted the water surface, the counter value was read and the height of water level was displayed. A water level measuring network was constructed with a number of water level meters based on the MODBUS protocol and RS485. The water level measuring network has been used on the Yangtze River model and achieved the expected results.
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