BACKGROUND:Clear aligners,due to their special material properties,are more prone to the"roller coaster effect"during the process of extracting the maxillary first premolar and closing the gap by retracting the anterior teeth,tilting and moving the teeth,leading to deepening of the anterior overjet and opening of the posterior teeth.There are fewer related studies at present concerning whether the thickness or stiffness of the aligner can be changed to reduce the"roller coaster effect"and better control the orthodontic tooth movement,.OBJECTIVE:To analyze the differences in tooth movement control ability of clear aligners of different thicknesses and stiffness when internally retracting maxillary anterior teeth by means of the three-dimensional finite element method.METHODS:Cone beam CT data of patients with convex profile were imported into Mimics and other software to simulate clinical cases.Three-dimensional finite element models were constructed to remove the first premolars,including the maxilla,teeth,and periodontal ligaments,while the diaphragms of clear aligners with thicknesses of 0.50 mm and 0.75 mm were assembled.Four sets of working conditions were created by loading the material properties of two Young's modulus of 1 000 MPa and 2 000 MPa.According to the clinical design to close of the extraction gap,and analyze the distribution of periodontal ligament stress,the displacement trend and the initial displacement of the teeth after loading and calculating in Workbench 2023 R1 software.RESULTS AND CONCLUSION:(1)The Von-Mises stress distribution pattern of periodontal ligament was consistent among the four working conditions,with the maximum value mainly distributed at the cervical part of teeth.The thicker diaphragm of the aligner,the higher the Von-Mises stress;the higher Young's modulus of the aligner,the higher the Von-Mises stress.(2)Under the four working conditions,the overall displacement trend of the maxillary dentition was that the crowns of the anterior teeth moved towards the lingual side and the roots towards the labial side,while the crowns of the posterior teeth moved towards the proximal-medial side and the roots towards the distal-medial side,and it was observed that the crown-root displacements of the teeth were in the opposite direction in all the conditions,and that the displacement of the crowns was greater than the displacement of the roots.Except for canines,the thicker the aligner diaphragm,the lower the R/C value(root-crown displacement ratio);the higher the modulus of elasticity of the aligner diaphragm,the lower the R/C value.(3)The results showed that when the maxillary anterior teeth were internally retracted using invisible aligners,the teeth showed a tendency to tilt and move without incisor torque compensation being designed;the greater the thickness of the aligner and the elastic modulus,the greater the control of the teeth,and the tendency of the teeth to tilt and move decreased;and the cuspids had to be controlled by other auxiliary means.

BACKGROUND:Clear aligners,due to their special material properties,are more prone to the"roller coaster effect"during the process of extracting the maxillary first premolar and closing the gap by retracting the anterior teeth,tilting and moving the teeth,leading to deepening of the anterior overjet and opening of the posterior teeth.There are fewer related studies at present concerning whether the thickness or stiffness of the aligner can be changed to reduce the"roller coaster effect"and better control the orthodontic tooth movement,.OBJECTIVE:To analyze the differences in tooth movement control ability of clear aligners of different thicknesses and stiffness when internally retracting maxillary anterior teeth by means of the three-dimensional finite element method.METHODS:Cone beam CT data of patients with convex profile were imported into Mimics and other software to simulate clinical cases.Three-dimensional finite element models were constructed to remove the first premolars,including the maxilla,teeth,and periodontal ligaments,while the diaphragms of clear aligners with thicknesses of 0.50 mm and 0.75 mm were assembled.Four sets of working conditions were created by loading the material properties of two Young's modulus of 1 000 MPa and 2 000 MPa.According to the clinical design to close of the extraction gap,and analyze the distribution of periodontal ligament stress,the displacement trend and the initial displacement of the teeth after loading and calculating in Workbench 2023 R1 software.RESULTS AND CONCLUSION:(1)The Von-Mises stress distribution pattern of periodontal ligament was consistent among the four working conditions,with the maximum value mainly distributed at the cervical part of teeth.The thicker diaphragm of the aligner,the higher the Von-Mises stress;the higher Young's modulus of the aligner,the higher the Von-Mises stress.(2)Under the four working conditions,the overall displacement trend of the maxillary dentition was that the crowns of the anterior teeth moved towards the lingual side and the roots towards the labial side,while the crowns of the posterior teeth moved towards the proximal-medial side and the roots towards the distal-medial side,and it was observed that the crown-root displacements of the teeth were in the opposite direction in all the conditions,and that the displacement of the crowns was greater than the displacement of the roots.Except for canines,the thicker the aligner diaphragm,the lower the R/C value(root-crown displacement ratio);the higher the modulus of elasticity of the aligner diaphragm,the lower the R/C value.(3)The results showed that when the maxillary anterior teeth were internally retracted using invisible aligners,the teeth showed a tendency to tilt and move without incisor torque compensation being designed;the greater the thickness of the aligner and the elastic modulus,the greater the control of the teeth,and the tendency of the teeth to tilt and move decreased;and the cuspids had to be controlled by other auxiliary means.

Objective To investigate the biomechanical characteristics of orthodontic tooth movement at different alveolar bone heights and provide a theoretical reference for orthodontic clinical treatment.Methods Four groups of mandibular dentition finite element models were established:the normal alveolar bone height,and 1/3,1/2,and 2/3 reductions in height.The lingual,distal,and intrusion movements of the mandibular central incisor were simulated under different loads.The distribution and variations in periodontal stress and tooth displacement were analyzed.Results Under three movements,the degree of stress concentration in the cervical area of the tooth and the periodontal equivalent force increased as the alveolar bone height decreased and the orthodontic force increased.Meanwhile,the displacement at each observation point and the crown-root displacement difference increased,and the tendency for inclination movement of the teeth aggravated.When the alveolar bone height was reduced to 2/3,the orthodontic force under lingual and distal movement increased to 150 g and that under intrusion movement increased to 100 g.The periodontal equivalent force increased to the maximum value,and the tendency of tooth inclination movement was most significant.Conclusions A reduction in the alveolar bone height aggravates the stress concentration at the top of the alveolar ridge and the tendency for inclination movement of the teeth.For orthodontic patients with an inferior periodontal condition,the orthodontic force should be reduced according to the alveolar bone height to ensure a safe and effective orthodontic treatment.

Objective To observe the effect of preoperative muscle strength training combined with postoperative BIODEX balance function training in improving the motor function of patients with total hip arthroplasty (THA). Methods A total of 110 patients with THA from January 2021 to December 2022 were selected as research objects, and were divided into observation group and control group by the simple randomization method, with 55 cases in each group. The control group received conventional postoperative rehabilitation training, while the observation group was treated with muscle strength training and BIODEX balance function training. Imaging indicators (acetabular abduction angle, anterior inclination angle, proportion of acetabular cup in safe zone, and centering rate of femoral prosthesis) at 5 days after surgery were compared between two groups; the joint motor function (Harris score for hip joint), balance ability [Berg Balance Scale (BBS)] and daily activity ability [Activities of Daily Life Scale (ADL)] before treatment and one month after treatment were compared between the two groups. Results There were no significant differences in acetabular abduction angle, anterior inclination angle, proportion of acetabular cup in safe zone and centering rate of femoral prosthesis between the two groups at 5 days after surgery (P>0.05); after one month of treatment, the Harris score for hip joint, the BBS score and ADL score in both group increased significantly, and the scores in the observation group were significantly higher than those in the control group (P < 0.05). Conclusion Preoperative muscle strength training combined with postoperative BIODEX balance function training shows a significant therapeutic effect, which can effectively improve the hip motor function and enhance the balance control ability in patients with THA.

Objective To explore the application effect of advanced lung rehabilitation programs in patients un-dergoing high flow nasal cannula oxygen therapy(HFNC).Methods Convenience sampling method was used to se-lect 40 HFNC patients admitted to the respiratory department,ICU,coronary heart disease monitoring unit,and other departments of a tertiary A comprehensive hospital in Tianjin from January to June 2023 as the experimental group,and 40 HFNC patients admitted from June to December 2022 as the control group.Both groups of patients received HFNC treatment during hospitalization and continued at home,while the experimental group adopts the information-motivation-behavioral skills(IMB)model as the theoretical basis,implements advanced pulmonary rehabili-tation during the stable condition period,discharge preparation period,and home rehabilitation period,and imple-ments compliance management of home pulmonary rehabilitation through cloud follow-up,and the control group re-ceived routine lung rehabilitation and home follow-up.The degree of respiratory distress,6-minute walking distance,exercise self-efficacy,quality of life were compared between the 2 groups before intervention,2 months and 6 months after intervention,and compliance with home pulmonary rehabilitation was compared between the 2 groups 6 months after intervention.Results The repeated measures analysis of variance showed that there was an interaction effect between time and the 2 groups in terms of difficulty in breathing,6-minute walking distance,exercise self-ef-ficacy,and quality of life(P＜0.05).Simple effect analysis showed that after 2 and 6 months of intervention,the ex-perimental group performed better than the control group in the respiratory distress,6-minute walking distance,exer-cise self-efficacy,and quality of life(P＜0.05).Within 6 months of intervention,the compliance of home pulmonary rehabilitation in the experimental group was better than that in the control group,and the difference was statistically significant(P＜0.05).Conclusion The application of advanced pulmonary rehabilitation programme based on IMB can improve respiratory symptoms and improve exercise self-efficacy and adherence to pulmonary rehabilitation,en-hance activity endurance and improve quality of life.

Objective To investigate the biomechanical characteristics of orthodontic tooth movement at different alveolar bone heights and provide a theoretical reference for orthodontic clinical treatment.Methods Four groups of mandibular dentition finite element models were established:the normal alveolar bone height,and 1/3,1/2,and 2/3 reductions in height.The lingual,distal,and intrusion movements of the mandibular central incisor were simulated under different loads.The distribution and variations in periodontal stress and tooth displacement were analyzed.Results Under three movements,the degree of stress concentration in the cervical area of the tooth and the periodontal equivalent force increased as the alveolar bone height decreased and the orthodontic force increased.Meanwhile,the displacement at each observation point and the crown-root displacement difference increased,and the tendency for inclination movement of the teeth aggravated.When the alveolar bone height was reduced to 2/3,the orthodontic force under lingual and distal movement increased to 150 g and that under intrusion movement increased to 100 g.The periodontal equivalent force increased to the maximum value,and the tendency of tooth inclination movement was most significant.Conclusions A reduction in the alveolar bone height aggravates the stress concentration at the top of the alveolar ridge and the tendency for inclination movement of the teeth.For orthodontic patients with an inferior periodontal condition,the orthodontic force should be reduced according to the alveolar bone height to ensure a safe and effective orthodontic treatment.

OBJECTIVE To establish characteristic HPLC chromatograms for Jubei mixture, and to simultaneous determine its six components by HPLC-ELSD. METHODS An HPLC specific chromatogram of the Jubei mixture was established. The chromatographic column was Agilent ZORBAX-C18(250 mm×4.6 mm, 5 μm), gradient elution was conducted with acetonitrile(A)-0.1% phosphoric acid aqueous solution(B) as the mobile phase, the flow rate was 1.0 mL·min-1, and the column temperature was 30℃, the detection wavelength was 250 nm. An HPLC-ELSD method was established and the chromatography was accomplished on a Waters T3 C18(250 mm×4.6 mm, 5 μm) column, the mobile phase consisted of acetonitrile(A)-1% acetic acid aqueous solution(B) in a gradient mode, the flow rate was 1.0 mL·min-1, the column temperature was set at 30℃. RESULTS The characteristic chromatograms of the HPLC with baicalin as the reference peak was established, and eight common peaks were defined. The linear ranges of amygdalin, liquiritin, peimine, peiminine, platycodin D and ophiopogonin D were good within their own ranges(r ≥ 0.999). The average recovery were 99.1%, 98.6%, 100.9%, 97.7%, 98.9% and 98.0%, RSD were 0.4%, 1.0%, 1.1%, 1.2%, 0.7% and 1.3%, respectively. CONCLUSION The established methods can be used to qualitative identification and quantitative determination of Jubei mixture, can effectively used for evaluation and quality control of Jubei mixture.

Objective:To optimize the Manchester needs tool for injured children (MANTIC) scale , and evaluate its reliability and validity among injured children. Methods:The MANTIC scale was optimized through Delphi expert consultation and pre-tests. From March 2023 to June 2023 , a total of 317 injured children admitted in 7 level A tertiary hospitals in Zhejiang and Shandong provinces and their families were surveyed with general data, optimized MANTIC scale, and EuroQol 5-dimension health questionnaire for youth (EQ-5D-Y). Item analysis was conducted on the data of the 317 patients collected with optimized MANTIC scale through the test for homogeneity and value-based decision-making method and the content validity test of the scale was evaluated with item-level content validity index (I-CVI) and scale-level content validity index (S-CVI). It was evaluated with KMO test values and Bartlett′s test of sphericity to determine whether the scale was suitable for exploratory factors. The number of common factors was determined based on the K1 criterion and scree plot to further obtain the structural validity of the scale of the item load value. The correlation validity of the scale was evaluated with the correlation coefficient of the optimized MANTIC scale and EQ-5D-Y. The reliability of the scale was tested with Cronbach alpha coefficient and Guttman split-half reliability coefficient. Results:A total of 332 questionnaires were distributed, among which 317 valid ones were collected, with a response rate of 95.6%. The test of homogeneity in the item analysis showed that the correlation coefficient between each item and the total score of the scale was 0.40-0.80. The results of the value-based decision-making method showed that the critical ratio of high-and low-scored groups was 6.08-28.01. The quality of all the items met the retention requirements so that the reliability and validity tests could be continued. Validity test found that I-CVI was 0.83-1.00, consistent S-CVI was 0.83, and mean S-CVI was 0.95. In structural validity analysis, the KMO value was 0.96, and the Chi-square value of Bartlett′s test of sphericity was 10755.76 ( P<0.01). A total of 9 common factors were extracted with the K1 criterion (eigen value>1), and the scree plot indicated 9 common factors with a cumulative variance contribution rate of 73.46%. Factor extraction and rotation showed that the load value of each item of the scale ranged from 0.589 to 0.874. The correlation coefficient of the optimized MANTIC scale and EQ-5D-Y was r= 0.55 ( P<0.01).Reliability test showed that the Cronbach alpha coefficient of the total scale and all dimensions was 0.96 and 0.77-0.98, and the Guttman split-half reliability coefficient was 0.76 and 0.73-0.98. Conclusion:The optimized MANTIC scale can attain good reliability, validity, consistency and stability, and can reflect the concept to be expressed and the content to be evaluated, indicating that it can be used to evaluate the injury rehabilitation needs of injured children and their families throughout the entire treatment process.

Colonoscopy with polypectomy significantly reduces the incidence of colorectal cancer and cancer - related mortality. However, a pooled miss rate of 22% for polyps was documented. Aims: To explore the clinical application value of an artificial intelligence (AI)-based colorectal polyp diagnostic system for polyp detection. Methods: A total of 400 patients who underwent colonoscopy in the First Affiliated Hospital of Soochow University from September to November 2021 were selected according to the inclusion and exclusion criteria and were randomly divided into two groups: one group received routine colonoscopy, and the other group received AI system assisted colonoscopy. There were 200 cases in each group. The Boston Bowel Preparation Scale (BBPS) was used to evaluate bowel preparation quality. The primary outcome was polyp detection rate (PDR), and the secondary outcome was polyps per colonoscopy (PPC). Results: AI system significantly increased PDR and PPC (37.0% vs. 23.0%, 0.775 vs. 0.495, all P<0.05), especially for diminutive and small polyps (diminutive polyps: 23.0% vs. 13.0%, 0.410 vs. 0.295; small polyps: 16.0% vs. 8.0%, 0.255 vs. 0.095; all P<0.05). No significant difference in large polyp detection was observed between the two groups (all P>0.05). The bowel preparation quality was classified as“poor”(BBPS 0-5 points),“qualified”(BBPS 6-7 points) and“excellent”(BBPS 8-9 points). There were no significant differences in polyp detection between the two groups when the bowel preparation quality was“poor”or “excellent”(all P>0.05). PDR and PPC were significantly increased in AI group when the bowel preparation quality was “qualified”(33.0% vs. 20.0%, 0.670 vs. 0.450, all P<0.05). Conclusions: AI-based colorectal polyp diagnostic system can significantly improve PDR and PPC because of the significant increase in the number of diminutive and small polyps detected. In addition, when the bowel preparation is qualified, the AI system can play better for polyp detection.

Objective:To investigate the effect of treatment of spinal meningioma with microsurgical procedures.Methods:From January 2003 to March 2022, there were 120 patients who had spinal meningioma and treated in the Department of Neurosurgery, The First Affiliated Hospital of Sun Yat-sen University. Their clinical data were retrospectively analysed. Of the 120 patients, there were 90 females and 30 males, aged from 14 to 85 (average, 54) years old. According to McCormick Classification, 29 cases were in grade I, 59 cases were in grade II, 25 cases were in grade III, and 7 cases were in grade IV. They were all underwent microsurgery. Patients were followed up by outpatient service within 3 months after surgery, then reviewed by outpatient visits and telephone interviews. McCormick's classification method and MRI examination were used to analyse the neurological and imaging changes of the patients before and after the surgery.Results:A total of 113 patients had complete resection and 7 had the resection of most part of the spinal meningioma. No infection, cerebrospinal fluid leakage, other complications and death occurred. Three months after surgery, 95 patients achieved the improvement or even completely disappearance of symptoms (such as numbness, pain, limited movement, etc.). There were 23 patients who had the symptoms unchanged as what before the surgery. Two patients had the symptoms worsened after the surgery. At 3 months after surgery, 95 cases (79.2%) improved, 23 cases (19.2%) were stable, and 2 cases (1.6%) aggravated. According to McCormick classification method, 92 cases were in grade Ⅰ, 15 cases were in gradeⅡ, 10 cases were in grade Ⅲ, and 3 cases were in grade Ⅳ. MRI scans showed that the dural sac were well refluxed, and no recurrence was found.Conclusion:Microsurgery is safe and effective for removal of spinal meningioma, with significant improvement in symptoms with fewer complications.