Objective: This study investigated the effect of applying different torque values on the sagittal displacement tendency of mandibular incisors during intrusion using clear aligners, with the aim of providing a reference for achieving true vertical intrusion (intrusion without labiolingual movement) of mandibular incisors in clear aligner therapy. Methods: This study was approved by the institutional ethics committee. A volunteer with an incisor mandibular plane angle of 94° was selected. Using cone-beam computed tomography and intraoral scan data, a high-precision three-dimensional finite element model was established. An intrusion amount of 0.2 mm was set for the mandibular incisors, and four simulation groups were defined by applying 0°, 1°, 2°, and 3° of root labial torque. The displacement tendency of the incisors and the stress distribution within the periodontal ligament were analyzed. Results: When 0° of root labial torque was applied, the mandibular incisors exhibited intrusion accompanied by crown-labial, root-lingual inclination. When 1°-3° of root labial torque was applied, the mandibular incisors exhibited intrusion accompanied by the inclination gradually shifted from crown-labial, root-lingual towards crown-lingual, root-labial. Based on the line graph of sagittal displacement, the central incisors and lateral incisors approximated true vertical intrusion when 1.8° and 2.5° of root labial torque was applied, respectively. The mandibular canines consistently exhibited extrusion accompanied by labial crown inclination. Stress within the periodontal ligament of the incisors and canines was primarily concentrated at the root apex and cervical region. After applying root labial torque, the area of stress concentration in the incisors cervical periodontal ligament shifted from the labial side to the lingual side. The stress in the periodontal ligament at the cervical region of the canines is predominantly concentrated on the labial side. Conclusion Applying appropriate torque control during mandibular incisor intrusion with clear aligners facilitates true vertical intrusion, thereby enhancing the efficiency of the intrusion.

Objective:To observe the effect of old RBCs transfusion on cognitive function in rats and the improvement effect of mi -nocycline.Methods: Male SD rats at the age of 6 months were randomly divided into 4 groups.The RBCs were obtained from male rats by centrifuging the total blood and stored at 4℃.The rats of fresh RBCs group (group F) were transfused with the RBCs stored for 1 day.The rats of old RBCs group (group O) were transfused with the RBCs stored for 7 days.The rats of treatment group (group T) received 40 mg· kg-1 minocycline with intraperitoneal injection before the transfusion .The rats of the control group ( group C) were transfused with the normal saline .The brain levels of IL-1βand IL-6 were determined with Quantikine ELISA kits in 24 hours after the blood transfusion (n=6).The rats were subjected to Barnes maze tests after 1 week of the blood transfusion (n=10).Results:The brain levels of IL-1βand IL-6 in group O were higher than those in group C and F (P<0.05), which were lower in group T than those in group O(P<0.05).The rats of group O spent longer time finding the target box than those of group C and F in the Barnes maze (P<0.05), and the time was shorter in group T than that in group O (P<0.05).Conclusion: Old RBCs transfusion plays a role in neuro-inflammation and induces cognitive dysfunction in rats , which may be improved by minocycline .

The E (envelope) protein is the smallest structural protein in all coronaviruses and is the only viral structural protein in which no variation has been detected. We conducted genome sequencing and phylogenetic analyses of SARS-CoV. Based on genome sequencing, we predicted the E protein is a transmembrane (TM) protein characterized by a TM region with strong hydrophobicity and alpha-helix conformation. We identified a segment (NH2-_L-Cys-A-Y-Cys-Cys-N_-COOH) in the carboxyl-terminal region of the E protein that appears to form three disulfide bonds with another segment of corresponding cysteines in the carboxyl-terminus of the S (spike) protein. These bonds point to a possible structural association between the E and S proteins. Our phylogenetic analyses of the E protein sequences in all published coronaviruses place SARS-CoV in an independent group in Coronaviridae and suggest a non-human animal origin.
Amino Acid Sequence ; Base Sequence ; Cluster Analysis ; Codon ; genetics ; Gene Components ; Genome, Viral ; Membrane Glycoproteins ; metabolism ; Membrane Proteins ; genetics ; metabolism ; Molecular Sequence Data ; Phylogeny ; Protein Conformation ; SARS Virus ; genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Sequence Homology ; Spike Glycoprotein, Coronavirus ; Viral Envelope Proteins ; genetics ; metabolism