A series of soy protein isolate (SPI)-modified waterborne polyurethane (WPU) composite films were fabricated from WPU and SPI by a process involving blending, solution casting, and evaporation. The effects of SPI content on the structure and physical properties of the composite films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermogravimetry (DTG), scanning electron microscopy (SEM), water absorption measurement, water contact angle measurement, and tensile testing. The results showed that the water absorption, hydrophilicity, and tensile strength in the dry state of the composite films increased with an increase of SPI content. The effects of SPI content on the cytocompatibility and biodegradability of the composite films were investigated by in vitro cell culture and in vivo implantation experiments. Cell culture experiments revealed that the composite films exhibited improved cytocompatibility and SPI promoted the adhesion, growth, and proliferation of cells. The in vivo implantation experiments illustrated that the composite films had improved biodegradability after modification with SPI. These results indicated that SPI-modified WPU composite films had great potential as biomaterials.

Lavas erupted at ocean island hotspots such as Hawaii have diverse geochemical signatures. These ocean island basalts are thought to be derived from many sources with different chemical compositions within Earth's mantle and contain components of more primitive, less degassed material, as well as several recycled oceanic crustal components. Furthermore, the recycled oceanic crustal components display vastly different ages. The various components may be derived from different mantle reservoirs that are entrained and carried to the surface by mantle plumes, but it is unclear how individual plumes could successively sample each of these reservoirs or why the recycled oceanic crust would have variable ages. Here we use high-resolution numerical simulations to investigate the interaction between mantle plumes, subducted oceanic crust and a more primitive lower mantle reservoir. In our simulations, some subducted oceanic crust is entrained directly into mantle plumes, but a significant fraction of the crust-up to 10%-enters the more primitive reservoirs. As a result, mantle plumes entrain a variable combination of relatively young oceanic crust directly from the subducting slab, older oceanic crust that has been stirred with ancient more primitive material and background, depleted mantle. Cycling of oceanic crust through mantle reservoirs can therefore reconcile observations of different recycled oceanic crustal ages and explain the chemical complexity of hotspot lavas.