Objective:To investigate the effect of triply periodic minimal surfaces (TPMS) structure and ceramic volume fraction on the mechanical properties of polymer-infiltrated ceramic network (PICN) composite and reveal its strengthening and toughening mechanism.Methods:In this study, TPMS structures with gyroid (G), primitive (P), diamond (D), and ceramic volume fraction (40%, 55%, 70%, 85%) were designed. Porous zirconia scaffolds were prepared using stereolithography technology, and resin was infiltrated into the scaffolds through a vacuum. Then, the PICN composites were obtained after curing. The bending strength, elastic modulus and fracture toughness of PICN were tested using an electronic universal testing machine, with commercial PICN as the control group. The micromorphology of PICN was observed through stereomicroscope and scanning electron microscope. The cytocompatibility of PICN was verified by using cell counting kit, live/dead cell staining and phalloidin staining.Results:The bending strength values of PICN with different ceramic volume fractions ranged from 82.0 MPa to 376.0 MPa, and they gradually increased as the ceramic volume fraction rised. The elastic modulus values of PICN with different ceramic volume fractions ranged from 12.1 GPa to 56.1 GPa. The fracture toughness values of PICN with different ceramic volume fractions ranged from 1.7 MPa·m 1/2 to 6.5 MPa·m 1/2. The bending strength of 85G PICN reached 306.0 MPa, and it had the highest fracture toughness (6.5 MPa·m 1/2) and an appropriate elastic modulus between that of the control group and that of enamel. Under scanning electron microscopy, it could be observed that the cracks branch and deflect at the interface and eventually terminate within the resin phase. After co-culture with PICN, the survival rate of mouse fibroblasts exceeded 80%, indicating that PICN had no cytotoxicity. Conclusions:The PICN composite with TPMS structure can satisfy the mechanical properties and cytocompatibility of dental prosthesis.

Objective:To investigate the effect of triply periodic minimal surfaces (TPMS) structure and ceramic volume fraction on the mechanical properties of polymer-infiltrated ceramic network (PICN) composite and reveal its strengthening and toughening mechanism.Methods:In this study, TPMS structures with gyroid (G), primitive (P), diamond (D), and ceramic volume fraction (40%, 55%, 70%, 85%) were designed. Porous zirconia scaffolds were prepared using stereolithography technology, and resin was infiltrated into the scaffolds through a vacuum. Then, the PICN composites were obtained after curing. The bending strength, elastic modulus and fracture toughness of PICN were tested using an electronic universal testing machine, with commercial PICN as the control group. The micromorphology of PICN was observed through stereomicroscope and scanning electron microscope. The cytocompatibility of PICN was verified by using cell counting kit, live/dead cell staining and phalloidin staining.Results:The bending strength values of PICN with different ceramic volume fractions ranged from 82.0 MPa to 376.0 MPa, and they gradually increased as the ceramic volume fraction rised. The elastic modulus values of PICN with different ceramic volume fractions ranged from 12.1 GPa to 56.1 GPa. The fracture toughness values of PICN with different ceramic volume fractions ranged from 1.7 MPa·m 1/2 to 6.5 MPa·m 1/2. The bending strength of 85G PICN reached 306.0 MPa, and it had the highest fracture toughness (6.5 MPa·m 1/2) and an appropriate elastic modulus between that of the control group and that of enamel. Under scanning electron microscopy, it could be observed that the cracks branch and deflect at the interface and eventually terminate within the resin phase. After co-culture with PICN, the survival rate of mouse fibroblasts exceeded 80%, indicating that PICN had no cytotoxicity. Conclusions:The PICN composite with TPMS structure can satisfy the mechanical properties and cytocompatibility of dental prosthesis.

OBJECTIVE:To study the genetic diversity of germplasm resources of Duchesnea indica from Hunan. METHODS:The random amplified polymorphic DNA(RAPD)reaction system of germplasm resources was established and RAPD-PCR was ad-opted to detect the expressions of 24 groups of D. indica from Hunan(including 21 wild and 3 cultivated varietos in different geo-graphical distribution). Agarose gel electrophoresis was used to analyze the results and calculate allele number (Na),effective al-lele number (Ne) the polymorphism points percentage (PPB),Nei’s gene diversity index (H) and Shannon’s information index (I). RESULTS:Totally 14 polymorphic primers were screened and 90 electrophoresis bands were amplified,including 81 polymor-phic bands with Na of 1.900 0,Ne of 1.540 1,PPB of 90.0%,H of 0.312 8 and I of 0.467 5. CONCLUSIONS:The genetic diver-sity of D. indica from Hunan is rich,and there were differences in genetic background between the cultivated species and wild spe-cies;clustering results show significant correlation with geographic distribution.

AIM: To compare the volatile oils of Lonicera macranthoides Hands-Mazz. from three plantation. METHODS: The volatile oil of L. macranthoides Hands-Mazz. was studied by GC-MS. RESULTS and CONCLUSION: The volatile oil in three different samples contained 26 kinds of same components: such as Linaiool, Geraniol, a-Terpineol, 1-Octen-30ol,3-Henen-1-ol and so on. The content of Linaiool was the highest which was 15.17%, 28.85% and 31.88% in L. macranthoides Hands-Mazz. from Longhui County, Xupu County and Xinning County.

OBJECTIVE:To improve and optimize the extraction process of DNA from medicinal lily. METHODS: A new feasible DNA extraction method was available by modifying and optimizing the traditional CTAB extraction method. RESULTS:The OD260/OD280 of the total DNA extracted by the modified CTAB method ranged from 1.6 to 2.0 with clear electrophoresis strip, and its content and purity were all up to the standards for RAPD analysis.CONCLUSION: A simple and feasible extraction process of DNA from medicinal Lily was found out and the content and purity of the DNA extracted in this method can meet the requirements for gene engineering.