Hydroxyapatite (HA) is an important component of human bone and bone tissue engineering scaffolds. A plethora of bone tissue engineering scaffolds have been synthesized so far, including nano-HA/chitosan/gelatin (nHA/CG) scaffolds; and for seeding cells, stem cells, especially induced pluripotent stem cells (iPSCs), have been a promising cell source for bone tissue engineering recently. However, the influence of different HA nano-particle morphologies on the osteogenic differentiation of human iPSCs (hiPSCs) from human gingival fibroblasts (hGFs) is unknown. The purpose of this study was to investigate the osteogenic differentiation of hiPSCs from hGFs seeded on nHA/CG scaffolds with 2 shapes (rod and sphere) of nHA particles. Firstly, hGFs isolated from discarded normal gingival tissues were reprogrammed into hiPSCs. Secondly, hiPSCs were seeded on rod-like nHA/CG (rod-nHA/CG) and sphere-shaped nHA/CG (sphere-nHA/CG) scaffolds respectively and then cell/scaffold complexes were cultured in vitro. Scanning electron microscope, hematoxyline and eosin (HE) staining, Masson's staining, and quantitative real-time polymerase chain reaction techniques were used to examine hiPSC morphology, proliferation, and differentiation on rod-nHA/CG and sphere-nHA/CG scaffolds. Finally, hiPSCs composited with 2 kinds of nHA/CG were transplanted in vivo in a subcutaneous implantation model for 12 weeks; pure scaffolds were also transplanted as a blank control. HE, Masson's, and immunohistochemistry staining were applied to detect new bone regeneration ability. The results showed that sphere-nHA/CG significantly increased hiPSCs from hGF proliferation and osteogenic differentiation in vitro. hiPSCs and sphere-nHA/CG composities generated large bone, whereas hiPSCs and rod-nHA/CG composities produced tiny bone in vivo. Moreover, pure scaffolds without cells almost produced no bone. In conclusion, our work provided a potential innovative bone tissue engineering approach using clinically discarded gingival tissues and sphere-nHA/CG scaffolds.

According to the agronomic requirements of garlic sowing, the garlic morphology is studied and a garlic seed metering mechanism with excellent seeding performance is designed. Based on this design, a new garlic seeding machine with an adjustable-size seeding device is developed to realize efficient single-seed metering and seeding of different varieties of garlic. Further, the design scheme of the garlic seeder prototype is established, with the key components of the garlic seeding being designed on the basis of the garlic seeding mechanism. To achieve garlic single-seed metering for different varieties of garlic, the optimal adjustment size of the garlic seed metering device is determined through discrete element simulation analysis. A field experiment confirms the effectiveness of applying the proposed garlic planter to field sowing in terms of the metrics of missing seed and multiple seed rates. The results of the discrete element simulation test reveal that an adjustment size of 40 mm yields the best single-seed metering performance. At an operating speed of 15–35 rpm, the metering device can achieve more than an 80% qualification rate of single-seed metering, with a unit speed of 0.628–1.465 m/s. Thus, the developed garlic seeding device meets the requirements of precision sowing in China and can effectively realize the mechanized planting of garlic.

The radial forearm free flap (RFFF) is one of the commonly used flaps in the repair of head and neck soft tissue defects, especially small and medium-sized defects. The free skin grafts from abdomen are usually used to repair the RFFF donor site wound. This study aims to design a novel V-shaped RFFF, hoping that it might facilitate the direct closure of the forearm donor site wound. From August to December in 2019, 20 patients with oral cancers received radical surgeries, and Vshaped RFFFs were designed to repair the soft defects and the forearm donor site wound was directly closed. The patients were followed up for 6 months to assess the final outcome of repair. The results showed that the pre-designed V-shaped RFFF met the needs of soft tissue defect repair, with the size ranging from 24 cm 2 to 30 cm 2 . Fifteen patients with tongue cancers and four with buccal cancers had satisfactory repair results, and only one patient with buccal cancer had mild limitation of mouth opening. There were 3 patients with a small area of ischemia. The mean postoperative hospital stay was 13.85 AE 1.09 days. In 5 patients, wrist tilt motility decreased compared with that before surgery. The postoperative influence score of wrist exercise on daily life was 2.75 AE 0.44 points. In conclusion, the V-shaped RFFF can meet the needs of small and medium-sized defect repair. This novel design can directly close the forearm donor site wound, which avoids surgical trauma to secondary donor site, and significantly reduces related complications.

Aiming at the problems of low single-seed rate, high rate of missing seeds, high rate of multiple seeds, and low rate of upright seeds in the mechanized sowing of garlic seeds, this paper proposes a structural design scheme of a type hole wheel garlic seed metering device based on the characteristics of garlic species. Based on the agronomic requirements of garlic planting and the characteristics of garlic species, the mechanism of the hole wheel structure to improve the seed filling performance of the seed metering device was clarified, a structural parameter design of the key components of the device was established through theoretical calculations, and a single-factor simulation test was conducted using the Engineering Discrete Element Modelling (EDEM) software. Using the Design-Expert 11 data analysis software, a mathematical regression model of each test factor and test index was established, and the test factors were analyzed. The parameters were optimized, and the following was found to be the optimum parameter combination: seeding wheel speed of 30 rpm, profile hole depth of 18 mm, and adjustment length of the profile hole of 41 mm. The EDEM simulation test results showed a single-seed rate of 91.67% and a missing seed rate of 4.17%. The bench test results showed a single-seed rate of 89.2%, a missing seed rate of 5.0%, and a multiple seed rate of 5.8%. The field test results showed a single-seed rate of 88.44%, a multiple seed rate of 4.11%, a missing seed rate of 7.44%, a breakage rate of 1.11%, and an upright rate of 62.36%. The errors between the bench test/field test and the discrete element simulation test results were 2.7% and 3.5%, respectively, which were consistent with the simulation results, thus meeting the requirements of single-seed sowing using the garlic seed metering device.