BACKGROUND:Sema3A is a power secretory osteoprotective factor.However,studies about Sema3A-modified dental pulp stem cells(Sema3A-DPSCs)are rare. OBJECTIVE:To explore the osteogenic differentiation ability of Sema3A-DPSCs and their regulatory effect on the osteogenic differentiation of the pre-osteoblast cell line MC3T3-E1. METHODS:First,Sema3A-DPSCs were constructed using a lentivirus infection system carrying the Sema3A gene.Control lentivirus-treated DPSCs(Vector-DPSCs)were used as controls.Sema3A-DPSCs or Vector-DPSCs were co-cultured with proosteoblast line MC3T3-E1 at the ratio of 1∶1 and 1∶3 for 24 hours.Finally,the Sema3A-DPSCs,Vector-DPSCs and their co-cultured cells with MC3T3-E1 were cultured for osteogenic induction and differentiation.Osteogenic gene expression was detected by alkaline phosphatase staining,alizarin red staining and real-time quantitative RT-PCR to evaluate osteogenic differentiation ability. RESULTS AND CONCLUSION:(1)Sema3A mRNA and protein expression levels in Sema3A-DPSCs were significantly up-regulated.The level of secreted Sema3A in cell supernatant was up-regulated.(2)Compared with the Vector-DPSCs,mRNA expressions of osteogenic genes alkaline phosphatase,Runt-related transcription factor 2,osteocalcin and Sp7 transcription factors in Sema3A-DPSCs were up-regulated;the activity of alkaline phosphatase was enhanced,and the formation of mineralized nodules increased.(3)There were no obvious differences in proliferation between Sema3A-DPSCs and Vector-DPSCs.(4)Compared with MC3T3-E1/Vector-DPSCs co-culture system,the expression of MC3T3-E1 osteogenic genes was up-regulated,and the total alkaline phosphatase activity was enhanced and more mineralized nodules were formed in the MC3T3-E1/Sema3A-DPSCs co-culture system.(5)The results suggest that overexpression of Sema3A can enhance the osteogenic differentiation of DPSCs.Overexpression of Sema3A in DPSCs can promote osteogenic differentiation of MC3T3-E1 in the DPSCs/MC3T3-E1 co-culture system.

BACKGROUND:The reciprocal force generated by the molar distalization with clear aligners can lead to anchorage loss.The effect of arch shapes and missing second premolars on anchorage has not been reported. OBJECTIVE:To analyze the effect of arch shapes and missing second premolars on anchorage during molar distalization with clear aligners using the finite element method. METHODS:Cone-beam CT data from an adult male were acquired from the database to establish the maxilla-upper dentition-periodontium-rectangular attachment-clear aligner model.The distal movement amount designed on the bilateral second molars was set to 0.25 mm.First,there were two groups in the study:second premolar bilateral presence and absence groups.Then,four subgroups in each group were created:tapered arch,ovoid arch,square Class Ⅱ Division 1 arch,and Class Ⅱ Division 2 arch groups.The Ansys software was used to calculate the displacement of the anchorage tooth and the stress of the periodontal ligament. RESULTS AND CONCLUSION:Mesial tipping and extrusion of first molars and premolars,labial inclination and intrusion of anterior teeth occurred during the upper second molar distalization with clear aligners.When the bilateral second premolars were missing,the mesial displacement of first molars increased significantly while that of first premolars and anterior teeth decreased in all groups.The square Class Ⅱ Division 1 arch group showed the least anterior labial inclination,while the tapered arch group showed the most.There was no significant difference between the ovoid arch group and the tapered arch group.Moreover,the magnitude of tipping in the square Class Ⅱ Division 2 arch group was slightly higher than that in the Class Ⅱ Division 1 arch group.The stress of the periodontal ligament of the anchorage teeth was concentrated on the cervical and apical regions of the teeth.And the lowest stress level was detected in the square arch group.Compared with the other groups,the stress on the labial cervical area of the periodontal ligaments was also significantly relieved in the square arch group.To conclude,the square arch is more favorable in terms of anterior anchorage control and periodontal ligament stress distribution.Anterior labial inclination efficiency can be increased in cases of Class Ⅱ Division 2 by designing the anterior labial inclination in conjunction with molar distalization.If the second premolar is missing during molar distalization,it is not conducive to opening up the space in the area of the missing tooth.

BACKGROUND:The thin alveolar bone in the lower anterior region increases the risk of labial bone resorption when intruding the teeth with clear aligners.The effect of sagittal overcorrection design on the labiolingual control of mandibular anterior teeth intrusion has not been fully investigated. OBJECTIVE:To explore the effect of overcorrection on the changes in the displacement and stress of the mandibular anterior teeth,especially the cervical and apical regions. METHODS:Through a male volunteer cone-beam CT data,the three-dimensional reconstruction of the mandible and teeth was conducted in the MIMICS and GEOMAGIC software.Moreover,the models of periodontal ligaments,attachments,and appliances were created in the SOLIDWORKS software.First,the study was divided into canine intrusion group and incisor intrusion group.Then,the overcorrection(0°,1°,2°)was designed on the bilateral mandibular central and lateral incisors.A total of six models were established.The models were assembled and imported into the ANSYS software to analyze and calculate the displacement and stress level. RESULTS AND CONCLUSION:(1)In the canine intrusion group,canines intruded and tipped lingually while incisors extruded and tipped lingually.In the incisor intrusion group,canines extruded and tipped lingually while incisors intruded and tipped lingually.(2)Without overcorrection,the incisors necks moved lingually while apexes moved labially.With overcorrection,the incisors tended to be upright,followed by labial tilt.The least cervical and apical displacements were detected under 1° overcorrection.(3)With overcorrection,the incisal cervical stress concentration area shifted from labial to lingual in the canine intrusion group,whereas the stress concentration area shifted from lingual to labial in the incisor intrusion group.(4)The incisors tended to tilt lingually when intruding the mandibular anterior teeth with clear aligners.The sagittal overcorrection design was conductive to maintain the stable position of incisors.However,the amount of overcorrection should be moderate.Excessive overcorrection might increase the labial inclination tendencies of incisors.

Objective To study the differences in features of event-related potentials(ERPs)and target detection accuracy between five brain regions(frontal,temporal,central,parietal,and occipital)in target detection tasks based on rapid serial visual presentation(RSVP)brain computer interface(BCI)under six target concealment conditions.Methods Twelve participants were selected for the study,whose scalp electroencephalogram(EEG)signals were collected under the six concealment conditions using a NeuroScan SynAmps2 EEG acquisition system.The ERP waveforms,P300 amplitudes and latencies,among other things,were compared across the five brain regions.The hierarchical discriminant component analysis(HDCA)algorithm was used to classify the EEG signals while the differences in classification accuracy were probed across the five brain regions.Results(1)Under the six concealment conditions,target images elicited distinct ERP waveforms in all the five brain regions;(2)For P300 amplitudes,the temporal region exhibited the smallest values;(3)Regarding P300 latencies,the parietal and central regions showed longer durations than other brain regions(except for small camouflage and small occlusion conditions);(4)In terms of classification accuracy,the parietal and central regions outperformed other brain regions(except for the large camouflage condition).Conclusion The selection of parietal and central channels can offer a new perspective for enhancing the performance in concealed target detection based on RSVP-BCI,and is expected to spark new ideas for the design of miniaturized,simple and wearable BCI devices.

Objective To explore an overcorrection quantization method and related influencing factors through analyzing relationships between the achieved and preset intrusion values of mandibular anterior teeth with clear aligners.Methods Twenty pa-tients receiving Invisalign were recruited.The relative intrusion values in the ClinCheck software were recorded as the preset intrusion.The achieved intrusion values were measured through the digital model superimposition.Statistical analysis was conducted to assess the differences and linear relationships between the preset and achieved intrusion values,and investigate the effect of related factors such as intrusion amounts on the intrusion efficiency.Results For the mandibular anterior teeth,the mean intrusion efficiency was 62.2%,with the highest in the central incisors and the lowest in the canines.The intrusion amounts,incisors labial inclinations,and canine at-tachment types affected the intrusion efficiency.The differences between the preset and achieved values were significant,and the linear relationship existed.The formula of the intrusion overcorrection for the mandibular anterior teeth is"Z=(W-0.110)/0.533-W".Z re-presents the overcorrection and W represents the ideal intrusion.Conclusion The preset intrusion values in the treatment protocol could not be fully achieved.Moreover,correction should be designed in cases of mandibular canine intrusion,large amountsof intru-sion,orlingually inclined incisors.Compared to the optimized attachments,the vertical rectangular attachments on the mandibular ca-nines could improve the efficiency.

Objective To explore the effect of melatonin(MT)-modified PEEK implant assisted by polydopamine(PDA)coating on osteointegration in osteoporotic rats.Methods MT was adhered to PEEK implants with PDA coating as carrier.The physicochemical properties of the materials were analyzed by SEM image,water contact angle,FTIR and protein adsorption experiment.OVX-rBMSCs were inoculated on the surface of PEEK sheet and cultured.The cytoskeleton was stained and cell adhesion morphology was observed.Cell proliferation activity was evaluated by CCK-8 assay;key enzyme activities for osteogenic differentiation were analyzed by ALP stai-ning,and expression levels of osteoblast-related genes COL-1,Runx2,OPN,OCN,BMP-2 and ALP were detected by quantitative real-time PCR.In addition,implants were implanted into the femur of osteoporotic rats and bone volume on the implant surface was de-tected and quantified by Micro-CT.Results MT was successfully loaded on PEEK;the cell adhesion was better,and the proliferation activity and osteogenic differentiation ability were significantly higher than those of control group(P＜0.01).In the rat osteoporosis mod-el,there was more new bone formation around the modified PEEK implant(P＜0.01).Conclusion MT-modified PEEK implants have excellent biocompatibility and improve osteointegration in an osteoporotic environment.

Objective:To investigate the mechanism of long non-coding RNA taurine up-regulated gene 1(lncRNA TUG1)in acute pancreatitis(AP).Methods:The mouse pancreatic acinar cell line(MPC-83)was cultured in vitro,and treated with lipopoly-saccharide(LPS,10 μg/ml)and cerulein(Caerulein,100 nmol/L)for 3 h to establish the AP model.The experiment was divided into control group,AP group,AP+sh-NC group,AP+sh-TUG1 group,AP+sh-TUG1+inhibitor-NC group,and AP+sh-TUG1+miR-31-5p inhibitor group.Quantitative real-time PCR(qRT-PCR)was performed to measure the expression levels of lncRNA TUG1 and miR-31-5p in cells;CCK-8 method was performed to measure cell viability;flow cytometry was performed to measure apoptosis;ELISA was performed to measure the levels of IL-1β and tumor necrosis factor α(TNF-α)in the cell supernatant;and dual-luciferase reporter gene experiments was performed to verify the targeting relationship between lncRNA TUG1 and miR-31-5p.The AP mouse model was constructed,and after corresponding intervention,qRT-PCR was performed to determine the lncRNA TUG1 and miR-31-5p expres-sion levels in pancreatic tissue;the serum inflammatory factors IL-1β,TNF-α contents and amylase(AMY)and lipase(Lipase)activities were determined by kits;HE staining was performed to observe histopathological changes of pancreas;TUNEL was per-formed to detect apoptosis in pancreatic tissue.Results:In MPC-83 cells co-treated with Caerulein and LPS,the lncRNA TUG1 level,apoptosis rate,IL-1β and TNF-α levels were increased,while miR-31-5p level and cell viability were decreased(all P<0.05);knock-down of lncRNA TUG1 up-regulated miR-31-5p,increased cell viability,decreased IL-1β and TNF-α levels,and inhibited cell apop-tosis(all P<0.05);down-regulation of miR-31-5p expression attenuated the inhibitory effect of lncRNA TUG1 knockdown on cellular inflammatory responses.miR-31-5p was a direct target of lncRNA TUG1.Knockdown of lncRNA TUG1 expression in vivo was able to up-regulate the expression of miR-31-5p in pancreatic tissue of AP mice,reduce the levels of IL-1β and TNF-α,reduce cell apoptosis,and improve pancreatic tissue damage.Conclusion:Knockdown of lncRNA TUG1 may improve AP by up-regulating the expression level of miR-31-5p and inhibiting the inflammatory response.

In recent years, clear aligner technology has been maturing and is rapidly gaining popularity in the orthodontic market for its aesthetic and removable properties. However, despite the background of its large-scale clinical application, mechanical properties of clear aligners need to be studied in depth. This paper reviews the factors influencing mechanical properties of clear aligners and the current status of research to provide evidence-based guidance for clinical application.

Objective:To analyze the morbidity characteristics of new occupational diseases in Taian City from 2006 to 2021 and provide scientific evidence for local prevention and treatment of occupational diseases.Methods:In March 2022, the data of newly diagnosed occupational diseases in Taian City from 2006 to 2021 were obtained from Information Monitoring System for Occupational Diseases and Health Hazards. A descriptive analysis was performed for the distribution of onset age, working years, types of occupational diseases, region, industries, enterprise scale, enterprise economic type and the epidemic trend of occupational diseases.Results:1362 cases of occupational diseases in 29 species of 9 categories were reported in Taian City from 2006 to 2021, including 1311 males and 51 females. The M ( P25, P75) of onset age and working age were 53 (47, 64) and 24.08 (16.56, 29.25) respectively. The top three categories of occupational diseases were occupational pneumoconiosis and other respiratory diseases (1128 cases, 82.82%), occupational otolaryngology and oral diseases (107 cases, 7.86%), and occupational chemical poisoning (70 cases, 5.14%) in sequence. Coal worker's pneumoconiosis, noise deafness, silicosis, poisoning of manganese and its compounds and cataract were the top five species of occupational diseases, which accounted for 69.60% (948/1362), 7.64% (104/1362), 5.58% (76/1362), 3.38% (46/1362) and 2.94% (40/1362) of the total cases of occupational diseases.There were significant differences among the composition of occupational diseases categories reported annually ( P<0.001), but the number of occupational pneumoconiosis and other respiratory diseases was the highest on each year. The number of occupational diseases showed a decreasing trend with the year, and the optimal fitting curve was an growth curve. The number of newly diagnosed occupational diseases was predicted to be 172 cases from 2022 to 2026. Occupational pneumoconiosis and other respiratory diseases was the main disease in 6 counties. The occupational diseases cases were mainly distributed in Feicheng County and Xintai County, with 520 cases and 504 cases respectively, accounting for 75.18% of occupational diseases cases. The coal mining and washing industry had the largest number of occupational diseases cases, accounting for 73.05% of all occupational diseases cases. 91.85% of occupational diseases cases came from large and medium-sized enterprises. The economic type of enterprises with the most occupational diseases was state-owned enterprises, accounting for 74.52% of occupational diseases cases. Conclusion:The predominant occupational diseases in Taian City are occupational pneumoconiosis and other respiratory diseases, occupational otolaryngology and oral diseases, occupational chemical poisoning. And the prevention and control of occupational diseases should be strengthened in key industries such as coal mining and washing industry, key enterprises such as state-owned large and medium-sized enterprises.

Objective:To analyze the morbidity characteristics of new occupational diseases in Taian City from 2006 to 2021 and provide scientific evidence for local prevention and treatment of occupational diseases.Methods:In March 2022, the data of newly diagnosed occupational diseases in Taian City from 2006 to 2021 were obtained from Information Monitoring System for Occupational Diseases and Health Hazards. A descriptive analysis was performed for the distribution of onset age, working years, types of occupational diseases, region, industries, enterprise scale, enterprise economic type and the epidemic trend of occupational diseases.Results:1362 cases of occupational diseases in 29 species of 9 categories were reported in Taian City from 2006 to 2021, including 1311 males and 51 females. The M ( P25, P75) of onset age and working age were 53 (47, 64) and 24.08 (16.56, 29.25) respectively. The top three categories of occupational diseases were occupational pneumoconiosis and other respiratory diseases (1128 cases, 82.82%), occupational otolaryngology and oral diseases (107 cases, 7.86%), and occupational chemical poisoning (70 cases, 5.14%) in sequence. Coal worker's pneumoconiosis, noise deafness, silicosis, poisoning of manganese and its compounds and cataract were the top five species of occupational diseases, which accounted for 69.60% (948/1362), 7.64% (104/1362), 5.58% (76/1362), 3.38% (46/1362) and 2.94% (40/1362) of the total cases of occupational diseases.There were significant differences among the composition of occupational diseases categories reported annually ( P<0.001), but the number of occupational pneumoconiosis and other respiratory diseases was the highest on each year. The number of occupational diseases showed a decreasing trend with the year, and the optimal fitting curve was an growth curve. The number of newly diagnosed occupational diseases was predicted to be 172 cases from 2022 to 2026. Occupational pneumoconiosis and other respiratory diseases was the main disease in 6 counties. The occupational diseases cases were mainly distributed in Feicheng County and Xintai County, with 520 cases and 504 cases respectively, accounting for 75.18% of occupational diseases cases. The coal mining and washing industry had the largest number of occupational diseases cases, accounting for 73.05% of all occupational diseases cases. 91.85% of occupational diseases cases came from large and medium-sized enterprises. The economic type of enterprises with the most occupational diseases was state-owned enterprises, accounting for 74.52% of occupational diseases cases. Conclusion:The predominant occupational diseases in Taian City are occupational pneumoconiosis and other respiratory diseases, occupational otolaryngology and oral diseases, occupational chemical poisoning. And the prevention and control of occupational diseases should be strengthened in key industries such as coal mining and washing industry, key enterprises such as state-owned large and medium-sized enterprises.