Regeneration and anti-migration of sand waves associated with sand mining in the Taiwan Shoal

Sand waves in the Taiwan Shoal are characterized by two distinct spatial scales. Giant sand waves have a length of2 kilometers with height between 5 m and 25 m, whilst small sand waves is less than 100-m long with height less than 5 m between giant sand wave peaks(crests). A series of five high-resolution multi-beam echo-sounding surveys between 2012 and 2020 in the middle of Taiwan Shoal indicated that artificial dredging on the giant sand waves had caused sand wave reform and evolution. Overall, the removal of giant sand waves significantly affected the migration of small sand waves adjacent to the dredging site, with the latter on both sides of the former appear to migrate towards the dredging pit. Moreover, in the dredging area, new sand waves emerged with wavelength much smaller than the original giant sand waves, while the convergent pattern of the small sand waves tends to store and form the giant sand waves, which might spread far beyond the survey period.

A Novel Method to Improve the Physical Property and Biocompatibility of Decellularized Heart Valve Scaffold with Sericin and Polydopamine

Cardiac valve replacement is an effective method to treat valvular heart disease.Artificial valves used routinely in clinic still have defects.In our study,we explored a novel method to modify the performance of Decellularized Heart Valve(DHV)scaffold.The decellularized porcine aortic valve was prepared using sequential hydrophile and lipophile solubilization method.The sericin was extracted from silk fibroin-deficient silkworm cocoon by lithium bromide method.First,DHV was immersed in sericin solution to produce the sericin–DHV composite scaffold.Then,we modified the DHV by making a Polydopamine(PDA)coating on the DHV first and then binding the sericin.The physical properties and biological compatibility of our composite scaffold were assessed in vitro and in vivo.Sericin were successfully prepared,combined to DHV and improved its biocompatibility.PDA coating further promoted the combination of sericin on DHV and improved the physical properties of scaffolds.The decay rate of our modified valve scaffold was decreased in vivo and it showed good compatibility with blood.In conclusion,our modification improved the physical properties and biocompatibility of the valve scaffold.The combination of PDA and sericin promoted the recellularization of decellularized valves,showing great potential to be a novel artificial valve.