Objective: To investigate the three-dimensional forces in real-time at different tips of the posteriors created by clear aligners on maxillary teeth during en-masse retraction of anteriors after 2 first premolars extraction treatment. Methods: Four groups of maxillary models with different tips of posteriors(T1-upright of posteriors, T2-posteriors with distal inclination of 5°, T3-posteriors with mesial inclination of 5°, T4-posteriors with mesial inclination of 10°) undergoing 0.25 mm en-masse retraction treatment using clear aligners were simulated on a multi-axis force/torque transducer measurement system. When each clear aligner was inserted, a computer connected to the transducer collected and recorded the three-dimensional force of every tooth in real-time. Each group included 12 aligners. Results: Incisors received smaller lingual and extrusive forces; canines received greater distal forces; smaller mesial forces were observed on the posteriors, and molars received greater buccal and extrusive forces in T2,compared with T1,which showed statistically significant differences(P<0.05). Incisors received smaller lingual and extrusive forces; canines received greater distal forces; greater mesial forces were observed on the posteriors, and molars received greater buccal and extrusive forces in T3 and T4,compared with T1,which showed statistically significant differences(P<0.05). Conclusion Posteriors with distal inclination contributed to the torque of the anterior and anchorage of posteriors. In group T2 posterior teeth experienced larger buccal forces and extrusive forces than in group T1. When the posteriors crown inclined mesially, the anterior teeth were more prone to lingual tip and caused overbite. The more mesially inclined the posterior teeth were, the more serious overbite was, and the posterior teeth were more prone to anchorage loss.

TNFR-Fc is an important fusion protein that has great potential in therapeutic and diagnostic applications. We developed an efficient fed-batch process for GS-CHO cells to produce TNFR-Fc. The rationale of this fed-batch process relies on the supply of sufficient nutrients to meet the requirements of cell metabolism. The optimal feed medium was designed through ration design. A metabolically responsive feeding strategy was designed and dynamically adjusted based on the residual glucose concentration determined off-line. In this process, the maximal viable cell density and antibody concentration reached above 9.4x10(6) cells/mL and 207 mg/L, respectively. Compared with the batch process, the newly developed fed-batch process increased the cell yield by 3.4 fold and the final antibody concentration by 3 fold. This fed-batch process would therefore facilitate the production of therapeutic antibody by GS-CHO cells.
Animals ; CHO Cells ; Cell Culture Techniques ; methods ; Cricetinae ; Cricetulus ; Culture Media ; Etanercept ; Glucose ; analysis ; Immunoglobulin G ; biosynthesis ; genetics ; Receptors, Tumor Necrosis Factor ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics