Design and validation of a surgical guide for the retrieval of foreign body instruments in jaw / 解剖学报

Objective To design and validate a novel surgical guide for retrieval of foreign body in jaw. Methods Firstly, a surgical guide based on cone beam computed tomography and trephine technique was designed to remove broken dental instrument fragments. Its feasibility and accuracy were assessed by removing broken dental instrument in goat mandible, and then it was successfully applied in clinical cases. The linear and angular discrepancies between actual and planned columnar bone with imaginary fragment was analyzed. The euclidean distance was measured at the hex and apex of the columnar bone and the angle of axis deviation was also calculated. We obtained seven parameters (cdh, cda, hdh, hda, vdh, vda, and ad) to describe deviations. Results Mean central deviation at the hex and apex was (0.51 ± 0.14) mm and (0.62 ± 0.19) mm, respectively. Accompanying mean values were as follow: horizontal deviation at the hex was (0.48 ± 0.16) mm, horizontal deviation at the apex was (0.52 ± 0.22) mm, vertical deviation at the hex was (0.17 ± 0.09) mm, vertical deviation at the apex was (0.29 ± 0.13) mm, and angular deviation of (5.38 ± 3.43) degrees. In a clinical case, the guide successfully located and removed the fracture file. Conclusion This study reveals that this kind novel surgical guide could aid to locate and remove the foreign body in jaw.

Screening of Lomefloxacin Aptamers Based on Polydopamine Nanospheres / 分析化学

Screening aptamers using nano-materials ( such as graphene oxide, gold nanoparticle, carbon nano-tube, etc. ) that can quench fluorescence and absorb single stranded DNA using hydrogen bond, π-πbond, charge transfer, and other non-covalent ways to combine with ssDNA, but without other conformational DNA, can excellently separate specific aptamers from non-specific ones. In this case, we can shorten the cycle numbers, enhance the success rate, and reduce the labour intensity of systematic evolution of ligands by exponential enrichment ( SELEX) . Especially for small molecular target, due to its difficulty in immobilization and small size, it is difficult to use traditional methods such as SPR-SELEX or affinity-SELEX for screening. In this experiment, polydopamine nanospheres ( MNPs@PDAs) were used to screen the Lomefloxacin. Also, we used magnetic separation technique to screen small molecular target rapidly. The interaction between aptamer candidates and the target could be monitored by recovery ratio of ssDNA and the whole MNPs@PDAs-SELEX process was performed through seven-round selection. As a result, we successfully obtained the aptamer named AF-3 which could recognize the lomefloxacin with high affinity (KD=(17. 57±0. 5) nmol/L). This screening method based on MNPs@PDAs makes it a promising reagent in the efficient aptamers selection of other targets.