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 explore the differentially expressed mRNAs and related biological processes and pathways in fractional low-dose ionizing radiation (LDIR)-induced senescence of normal human bronchial epithelial (HBE) cells by high-throughput mRNA sequencing and bioinformatics techniques. Methods Senescence-associated β-galactosidase staining and senescence-associated secretion phenotype gene mRNA and protein expression levels were measured at 24 and 48 h after irradiating HBE cells 7 times at doses of 0, 50, 100, and 200 mGy, respectively. The differentially expressed genes were screened by high-throughput sequencing for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Results The senescence-positive area of fractional low-dose irradiated HBE cells increased in a dose-dependent manner (P < 0.05). The mRNA levels and protein expression of transforming growth factor-β1(TGF-β1) and matrix metalloproteinase-9(MMP-9) genes were increased in the 100 mGy × 7 and 200 mGy × 7 groups at 24 and 48 h after the end of irradiation compared with the control group. High-throughput sequencing showed that there were 882, 475, and 1205 differentially expressed mRNAs in each dose group compared with the control group. GO analysis showed that the differentially expressed mRNAs in each dose group were mainly enriched in biological processes such as cell cycle regulation, regulation of nitrogen compound metabolic process, regulation of cell division and response to stimulus. KEGG analysis showed that the differentially expressed mRNAs were mainly enriched in the pathways of cell cycle, cell senescence, and ferroptosis. Conclusion Fractional LDIR induced senescence in HBE cells, and differentially expressed mRNA-associated biological processes and pathways in senescent cells are related to cell cycle and cell senescence.

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.

Enhanced Recovery After Surgery (ERAS) is a standardized perioperative care plan aimed at optimizing perioperative management through a series of evidence-based interventions. In recent years, guidelines related to ERAS in gynecologic oncology have been successively updated. The International ERAS Society published guidelines on the application of ERAS in gynecologic oncology in 2016 and 2019. With the advancement of evidence-based research, these guidelines were further updated in 2023. This paper interprets the key points of the 2023 updated guidelines for the use of ERAS in gynecologic oncology patients, aiming to enhance perioperative management.

OBJECTIVES: Digital subtraction angiography (DSA) is the current gold standard for diagnosing spinal dural arteriovenous fistulas (SDAVF). However, DSA is invasive and associated with risks such as ionizing radiation and iodine contrast allergy. Contrast-enhanced magnetic resonance angiography (CE-MRA) with high temporal/high spatial resolution allows dynamic multiphase contrast-enhanced imaging with excellent detail. This study aims to evaluate the diagnostic value of spinal CE-MRA with high temporal/high spatial resolution for SDAVF. METHODS: Clinical data were retrospectively collected from patients who underwent both conventional spinal MRI and high temporal/high spatial resolution CE-MRA at Xiangya Hospital between January 1, 2021, and January 1, 2024, and who subsequently underwent DSA or surgery within 90 days. Two experienced radiologists independently reviewed all conventional MRI and CE-MRA images. The sensitivity and specificity of conventional MRI and CE-MRA for diagnosing SDAVF were calculated against the gold standard DSA findings. Kappa statistics were used to evaluate the consistency of MRI and CE-MRA compared to DSA. The diagnostic value was further assessed by calculating the area under curve (AUC) of the receiver operating characteristic (ROC). RESULTS: A total of 60 patients were included, of whom 47 were diagnosed with SDAVF and 13 were not. Conventional MRI had 3 false negatives and 1 false positive; CE-MRA had 2 false positives and 0 false negative. The sensitivity and specificity of conventional MRI were 93.62% and 92.31%, respectively. CE-MRA demonstrated 100% sensitivity and 84.62% specificity. The main cause of false positives was the misidentification of posterior spinal arteries as feeding arteries. CE-MRA clearly displayed most feeding arteries, and the accuracy of fistula localization was 74.47% (35/47). Kappa values for conventional MRI and CE-MRA were 0.814 and 0.896, respectively (both P<0.001), indicating good agreement, with CE-MRA outperforming conventional MRI. The AUCs for diagnosing SDAVF were 0.930 for conventional MRI and 0.923 for CE-MRA (both P<0.05). CONCLUSIONS Spinal CE-MRA with high temporal/high spatial resolution is a reliable, non-invasive imaging technique with high sensitivity for diagnosing SDAVF. It can clearly visualize feeding arteries and provides valuable preoperative diagnostic and localization information to support DSA or surgical planning.
Humans ; Central Nervous System Vascular Malformations/diagnosis* ; Male ; Female ; Retrospective Studies ; Middle Aged ; Magnetic Resonance Angiography/methods* ; Angiography, Digital Subtraction/methods* ; Aged ; Adult ; Sensitivity and Specificity ; Contrast Media ; Magnetic Resonance Imaging/methods*

The small G-protein Rac1 is the main regulatory factor of the actin cytoskeleton. Rac1 cycles between the inactive GDP-bound form and the active GTP-bound form. Rac1 not only promotes viral replication and infection, but also regulates the actin cytoskeleton rearrangement, adhesion, and invasion of glioma cells. In addition, Rac1 is implicated in human diseases such as tumors and epilepsy. This article reviews the latest research on the small G-protein Rac1 in virology, cell biology, and human pathology. It is found that the existence of Rac1 is closely related to the replication and infection of viruses, that is, inhibiting the existence of Rac1 can effectively reduce the replication and transportation of viruses, providing new ideas for the development of various therapeutic drugs targeting Rac1.
Humans ; rac1 GTP-Binding Protein/genetics* ; Virus Replication ; Glioma/pathology* ; Actin Cytoskeleton/metabolism* ; Animals

Taking the current situation and problems of medical humanities education as the background, the concept of narrative medicine was used to sort out and integrate various course materials of medical humanities, explore the multi-link linkage mode of medical humanities education, and organically integrate medical humanities courses scattered in medical education activities such as medical ethics, health law, doctor-patient communication, and health policy science with teaching stages, teaching resources, and teaching methods, forming vivid narrative medical materials throughout the entire process of medical humanities education, and improving teaching efficiency by sharing and optimizing resources. Through questionnaire analysis, it was found that there are many unsatisfactory aspects of medical humanities education. Further analysis of the issues focuses on the contradiction between learning willingness and time allocation, the lack of synchronization between teaching and social development, the lack of integration between courses, and insufficient innovation in teaching methods. Based on these, countermeasures were put forward to integrate narrative medical materials of medical humanities courses and build a platform for the application and communication of narrative medical materials.