The development and primary application of a deep learning convolutional neural network in the field of revision total hip arthroplasty CT segmentation / 中华骨科杂志

Objective:To develop a preoperative CT image segmentation algorithm based on artificial intelligence deep learning technology for total hip arthroplasty (THA) revision surgery, and to verify and preliminarily apply it.Methods:A total of 706 revision cases with clear CT data from April 2019 to October 2022 in Chinese PLA General Hospital were retrospectively analyzed, including 520 males, aged 58.45±18.13 years, and 186 females, aged 52.23±16.23 years. All of them were unilateral, and there were 402 hips on the left and 304 hips on the right. The transformer_unet convolutional neural network was constructed and trained using Tensorflow 1.15 to achieve intelligent segmentation of the revision THA CT images. Based on the developed three-dimensional planning system of total hip arthroplasty, an intelligent planning system for revision hip arthroplasty was preliminarily constructed. Dice overlap coefficient (DOC), average surface distance (ASD) and Hausdorff distance (HD) parameters were used to evaluate the segmentation accuracy of transformer_unet, full convolution network (FCN), 2D U-shaped Net and Deeplab v3 +, and segmentation time was used to evaluate the segmentation efficiency of these networks.Results:Compared with the FCN, 2D U-Net, and Deeplab v3+ learning curves, the transformer_unet network could achieve better training effect with less training amount.The DOC of transformer_unet was 95%±4%, the HD was 3.35±1.03 mm, and the ASD was 1.38±0.02 mm; FCN was 94%±4%, 4.83±1.90 mm, 1.42±0.03 mm; 2D U-Net was 93%±5%, 5.27±2.20 mm, and 1.46±0.02 mm, respectively. Deeplab v3+ was 92%±4%, 6.12±1.84 mm, 1.52±0.03 mm, respectively. The transformer_unet coefficients were better than those of the other three convolutional neural networks, and the differences were statistically significant (all P<0.05). The segmentation time of transformer_unet was 0.031±0.001 s, FCN was 0.038±0.002 s, 2D U-Net was 0.042±0.001 s, Deeplab v3+ was 0.048±0.002 s. The segmentation time of transformer_unet was less than that of the other three convolutional neural networks, and the difference was statistically significant ( P<0.05). Based on the results of previous studies, an artificial intelligence assisted preoperative planning system for THA revision surgery was initially constructed. Conclusion:Compared with FCN, 2D U-Net and Deeplab v3+, the transformer_unet convolutional neural network can complete the segmentation of the revision THA CT image more accurately and efficiently, which is expected to provide technical support for preoperative planning and surgical robots.

Effects of fluoride exposure on proliferation, apoptosis and osteogenic differentiation of mouse bone marrow mesenchymal stem cells / 中华地方病学杂志

Objective:To investigate the effects of fluoride exposure on proliferation, apoptosis and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in mice.Methods:BMSCs were isolated and cultured from femur bone marrow of C57BL/6 mice (6 - 8 weeks). The cells in passage 3 were used to detect the surface markers of stem cells by flow cytometry. The cells were cultured in media with a final fluoride concentration of 0.0, 0.1, 1.0, 5.0, 10.0, 15.0, 20.0 and 40.0 mg/L, respectively. The effects of different fluoride concentrations on BMSCs cell proliferation (CCK8 method), apoptosis (flow cytometry analysis), osteogenic differentiation ability [alizarin red and alkaline phosphatase (ALP) staining] were detected. Western blot was applied to detect the levels of apoptosis-related proteins [poly ADP-ribose polymerase (PARP)], mitogen-activated protein kinase (MAPK) pathway member proteins [extracellular regulated protein kinase 1/2 (ERK1/2), c-Jun amino-terminal kinase (JNK), p38 and phosphorylated ERK, JNK, p38 (p-ERK, p-JNK, p-p38)], osteogenic differentiation-related protein [Runt-related transcription factor 2 (Runx2), ALP] and Wnt/β-catenin pathway member proteins [glycogen synthase kinase-3β (GSK3β), phosphorylated GSK3β (p-GSK3β) and β-catenin]. Immunocytofluorescense staining was applied to evaluate the expression levels of p-GSK3β and β-catenin. The two pathways (MAPK and Wnt/β-catenin) were blocked by SP600125 and DKK-1, respectively, to testify their involvement in mechanisms of apoptosis and osteogenic differentiation.Results:The mouse BMSCs were successfully isolated and cultured. Flow cytometry analysis showed that the mesenchymal stem cell surface biomarkers (CD73, CD90 and CD105) were positively expressed. The comparison of cell proliferation at three time points (24, 48 and 72 h) in each concentration group was statistically significant ( F = 65.36, 160.04 and 365.32, P < 0.001), and the comparison of early apoptosis (24 h) in each concentration group was statistically significant ( F = 214.04, P < 0.001); compared with the 0.0 mg/L group, the cell proliferation in 15.0, 20.0 and 40.0 mg/L groups decreased, and the early apoptosis rate in 10.0, 15.0 and 20.0 mg/L groups increased ( P < 0.05). When cells were treated with 15.0 mg/L fluoride for 0 - 24 h, the p-JNK/JNK ratio was higher at 2, 4, 8, 12, 18 and 24 h compared with that at 0 min ( P < 0.05); compared with the fluoride group (15.0 mg/L), the early apoptosis rate of cells after SP600125 block decreased ( P < 0.05), and the protein expression levels of PARP and p-JNK decreased ( P < 0.05). After osteogenic induction, compared with the 0.0 mg/L group, in 0.1 and 1.0 mg/L groups ALP staining was enhanced and the number of calcified nodules increased, and the protein expression levels of Runx2 and ALP in the 0.1 and 1.0 mg/L groups were higher ( P < 0.05). After osteogenic induction, compared with the 0.0 mg/L group, the p-GSK3β/GSK3β ratio and β-catenin protein level were significantly higher in the 0.1 and 1.0 mg/L groups ( P < 0.05); and compared with the fluoride group (1.0 mg/L), addition of DKK-1 significantly decreased the protein expression levels of p-GSK3β and β-catenin and reduced the nuclear entry of β-catenin, and ALP staining decreased and the number of calcified nodules decreased. Conclusions:High concentration of fluoride (> 10.0 mg/L) inhibits the proliferation and promotes apoptosis of BMSCs, while low concentration of fluoride (0.1, 1.0 mg/L) promotes osteogenic differentiation. The MAPK/JNK pathway and the classical Wnt pathway are involved in the above cellular processes, respectively.

Determination of Impurities Including Polymers in Latamoxef Sodium by HPSEC / 中国药师

Objective:To establish a high performance size-exclusion chromatography ( HPSEC) method for the determination of impurities including polymers in latamoxef sodium. Methods:The analysis was performed on a Zenix SEC-150 column(7. 8 mm × 300 mm, 3 μm)with the mobile phase of 0. 005 mol·L-1 phosphate buffer solution [0. 005 mol·L-1 disodium hydrogen phosphate-0. 005 mol·L-1 sodium dihydrogen phosphate (61∶39), pH 7. 0] at a flow rate of 0. 8 ml·min-1. The detection wavelength was set at 254 nm. The column tempretrue was 25℃ and the injection volume was 10μl. Results:The impurities including polymers in latamoxef so-dium were completely separated from latamoxef. The linear range of latamoxef was 0. 98-97. 73 μg·ml-1(r=0. 999 9). The limit of quantitation of latamoxef was 2. 9 ng, and the detection limit was 1. 0 ng. The linear range of the total impurities was 0. 45-2. 8 mg· ml-1(r=0. 999 5). Conclusion: The established method is accurate, rapid and reproducible, and suitable for the determination of impurities including polymers in latamoxef sodium.

Comparison of extraction versus non-extraction orthodontic treatment results--a preliminary study / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study was to make a comparison between extraction and non-extraction orthodontic treatment results concerning teeth alignment, occlusal relation, facial profile and treatment interval.</p><p><b>METHODS</b>39 extraction-non-extraction borderline cases were selected by 5 orthodontic specialists through reviewing their pre-treatment records. 5 specialists were then asked to rank the results by marking the post-treatment record of each case. And then the samples were divided into different groups according to extraction, non-extraction and extraction pattern by reviewing case history.</p><p><b>RESULTS</b>No statistically significant difference was found in teeth alignment, overbite and overjet, midline symmetry, lateral occlusal relation and treatment intervals. However, the post-treatment facial profile of extraction groups obtained higher marks from 5 specialists (P = 0.001).</p><p><b>CONCLUSION</b>While both extraction and non-extraction treatment can achieve comparable results in teeth alignment and occlusal relation with equivalent time interval in borderline cases, extraction treatment, whatever extraction of four first premolars or second premolars is performed, can achieve better facial profile.</p>

Preliminary study of treatment mechanism and stability in deep overbite malocclusion with hyperdivergent and hypodivergent skeletal pattern / 北京大学学报(医学版)

40? or 40?)comprised 10 cases and the hypodivergent group (MP-SN

Three-dimensional measurement of tooth inclination in cases with successful treatment / 北京大学学报(医学版)

Objective:This study aimed to observe the differences of tooth inclinations among post treatment good cases of different malocclusions and untreated normal occlusions in order to give references on clinical adjusting of tooth inclinations. Methods:157 post treatment good cases were chosen and tooth inclinations were measured on post treatment casts using YM 2115 three dimensional measurement instrument. The measurement results were compared with those of untreated normal occlusions. Results:The inclination values of upper and lower incisors of Class Ⅰ groups are most close to those of untreated normal occlusions, which of upper central and lateral incisors are 9.6? and 8.7?, and of lower central and lateral incisors are 1.1? and-1.1?. In Class Ⅱ groups, lower incisors are markedly proclined (5.6? and 2.1?) and upper incisors are similar with untreated normal occlusions. In Class Ⅲ groups, upper incisors are markedly proclined (15.2? and 12.1?) and lower incisors are markedly retroclined (-3.7? and-4.9?). Conclusion:In order to achieve normal overjet and overbite, it is necessary to adjust the inclinations of upper and lower incisors when treated Class Ⅱ and Class Ⅲ malocclusions only by the method of orthodontic treatment.

Dentoalveolar compensation for vertical craniofacial pattern after orthodontic treatment / 实用口腔医学杂志

Objective: To investigate dentoalveolar compensation for vertical craniofacial pattern after orthodontic treatment. Methods:157 post-treatment cases with normal incisor relationships and various vertical craniofacial patterns were studied. Computerized post-treatment cephalometric analysis was performed to evaluate vertical craniofacial pattern and dentoalveolar parameters. Incisor torques were measured from study models. Correlation analysis was performed between skeletal and dental measurements.Results:①There was negative correlation between post-treatment upper central incisor torque and MP-SN angle(P