ABSTRACT
Objective To compare the measurement differences between the skull 3D printed model and the real specimen under different CT scan slice thicknesses, and to explore the effect of slice thickness on the accuracy of the 3D printed model. Methods Eight normal skull specimens (marked as Nos. f-8) (group N) were used for CT scanning with different slice thicknesses, specifically 0.625 mm (group A),1.25 mm (group B) , and 2.5mm (group C) ,3.75 mm (group D) , and 5 mm (group E) , and then earned out 3D reconstruction and 3D printing respectively, and compared the anatomical reduction degree of the foramen magnum diameter, anterior clinoid distance, and butterfly wing distance of the 3D printed skull model. Results The reduction degree of anatomical structure of 3D printed skull model decreased with the increase of CT slice thickness. There was no significant difference in the accuracy of 3D model among groups A, B and C (P >0.05 ) . There was a high correlation between group A, B and C and group N ( P < 0 .05 ).The size indexes and statistical values of group A, B and C were similar. Conclusion CT slice thickness has a significant effect on the accuracy and reduction of the 3D printed skull model. The 3D printed model with thin slice data (0.625 mm,1.25 mm,2.5 mm) has higher accuracy and less difference.
ABSTRACT
Objective To explore the possibility of adipose-derived stem cells (ADSCs) to differentiate into fibroblasts, and to provide an effective way for the effective solution of skin tissue engineering seed cells. Methods Primary ADSCs were obtained from inguinal fat of ten healthy adult SD rats,weighing 280-320 g,and cultured in vitro and purified. When primary ADSCs expansion to the 3rd passages,the following experiments were performed alkaline phosphatase test on the 16th day after osteogenesis induction,staining of alizarin red mineralized nodules on day 23 after osteogenesis induction, oil red O staining on day 12 after adipogenic induction; Flow cytometry detection of cell surface markers; Addition of conditioned medium to induce differentiation into fibroblasts,Photograph the changes of cell morphology on the 2nd, 4th, 6th, and 8th days after induction,MTT to detect cell viability at various time points;Scanning electron microscopy on day 6 and day 8 after induction;Immunocytochemical staining on day 8 after induction,detect the expression of vimentin, the main marker of fibroblasts. Results Primary ADSCs grew in long spindles, showed strong positive expression of alkaline phosphatase (ALP) after osteogenesis induction,and alizarin red staining showed red mineralized nodules;Aggregation of intracellular red-stained lipid droplets after adipogenic induction were found;Flow cytometry showed positive expression of mesenchymal stem cell-related marker CD90,and hematopoietic stem cell marker CD45 was negative. Morphology of ADSCs started to change on day 2 after induction into fibroblasts. On the 4th day after induction, the cells were in the shape of water droplets or short rods. On the 6th day after induction, the cells were protruded polygonal or triangular. Cells crowded and covered the bottom of the bottle on day 8 after induction,becoming slender fibrous. MTT test showed that the cell viability was significantly lower on the second day after induction than in the control group. There were no significant differences in cell viability on the 4th, 6th, and 8th days after induction compared with the control group. Scanning electron microscopy showed that the cells were triangular on the 6th day after induction, and the surface had more cilia. On the 8th day after induction, the cells were slender and fibrous, with small protrusions, and the surface cilia were dense. Vimentin was positively expressed in most cells on the 8th day after induction. Conclusion ADSCs can have the morphological characteristics of fibroblasts after induced differentiation in vitro; that can express fibroblasts marker protein.
ABSTRACT
In order to explore the genetic mutations of the H9N2 subtype avian influenza viruses isolated in Shandong, sixteen avian influenza virus subtype H9N2 were isolated from different areas of Shandong Province. The complete HA fragments of the viruses were amplified by RT-PCR and the sequences were analyzed on homology and heredity evolution after the cloning and sequencing of the products. The results showed that the amino acid motif of cleavage sites for all the sixteen virus in the HA gene were RSSR decrease GLF, which was consistent with the characterization of the LPAIV. Seven to nine potential glycosylation sites were found during the analysis and the receptor binding sites were relatively conservative except the 198 site. The Leucine(L) at the amino acid position 234 in the HA genes of all isolates indicated the potential of binding with SAalpha,2-6 receptor of mammals. Homology analysis showed that the homology of HA nucleotide and amino acid sequences was 96.3%-99.9% and 97.1%-99.6% for different strains. They belonged to a branch of the A/Duck/Hong Kong/Y280/97 in the phylogenetic tree.