Histone acetylation and methylation can affect chromatin conformation and regulate a variety of biological activities.Abnormal histone acetylation and methylation modifications are related to the occurrence and development of a variety of oral diseases.Histone acetylation and methylation increase or decrease in an orderly manner to regulate the development of teeth.Fluoride ions can destroy the balance between histone acetylation and methylation,which may be related to the occurrence of dental fluorosis.In addition,histone acetylation and methylation are involved in the regula-tion of oral inflammatory diseases.In the inflammatory microenvironment,the expression of histone acetyltransferase GCN5 decreases,and the expression of Dickkopf 1(DKK1)decreases,activating the Wnt/β-catenin pathway and ulti-mately inhibiting the osteogenic differentiation of periodontal ligament stem cells.Enhancer of zeste homolog 2(EZH2)and H3K27me3 levels were decreased in inflamed dental pulp tissues and cells.EZH2 inhibition inhibited the expres-sion of interleukin(IL)-1b,IL-6 and IL-8 in human dental pulp cells under inflammatory stimulation.Histone acetyla-tion/methylation modifications can interact with multiple signaling pathways to promote the occurrence and development of oral tumors and are related to the high invasiveness of salivary gland tumors.Small molecule drugs targeting histone acetylation and methylation-related enzymes can regulate the level of histone methylation/acetylation and have shown po-tential in the treatment of oral and maxillofacial diseases.For example,the histone deacetylase inhibitor vorinostat can inhibit the secretion of inflammation-related cytokines;it also promotes the maturation of odontoblasts and the formation of dentin-related matrix,demonstrating its potential in pulp preservation.Understanding the role of histone acetylation/methylation modifications in the occurrence and development of oral diseases will help promote research on epigenetic modifications in oral diseases and provide new perspectives for disease diagnosis and treatment.

OBJECTIVE: To explore the feasibility of using the bidirectional local distance based medical similarity index (MSI) to evaluate automatic segmentation on medical images. METHODS: Taking the intermediate risk clinical target volume for nasopharyngeal carcinoma manually segmented by an experience radiation oncologist as region of interest, using Atlas-based and deep-learning-based methods to obtain automatic segmentation respectively, and calculated multiple MSI and Dice similarity coefficient (DSC) between manual segmentation and automatic segmentation. Then the difference between MSI and DSC was comparatively analyzed. RESULTS: DSC values for Atlas-based and deep-learning-based automatic segmentation were 0.73 and 0.84 respectively. MSI values for them varied between 0.29~0.78 and 0.44~0.91 under different inside-outside-level. CONCLUSIONS It is feasible to use MSI to evaluate the results of automatic segmentation. By setting the penalty coefficient, it can reflect phenomena such as under-delineation and over-delineation, and improve the sensitivity of medical image contour similarity evaluation.
Feasibility Studies ; Radiotherapy Planning, Computer-Assisted

In the process of tumor growth, with the proliferation and expansion of cancer cells, the reconstruction of extracellular matrix (ECM) of cancer tissues, the restriction of surrounding tissues and the flow of cancer tissue interstitial fluid, the special stress environment is formed in the tumor tissues. Significant differences are found in the mechanical environment and mechanical characteristics of different regions of tumor tissues, that is, mechanical heterogeneity. The reseach shows that the mechanical properties of tumor tissue invasion frontier areas are more significant and complex. In particular, the epithelial-mesenchymal transition (EMT) of tumor cells also prefers to concentrate on this area. The mechanical stress generated by the invasion front can induce EMT of tumor cells through TWIST1, TGF-β, WNT and other force signal transduction pathways, and promote tumor cell invasion. From the perspective of tumor biomechanics, this review focuses on the relationship between mechanical heterogeneity of tumor cells and EMT, so as to provide the theoretical basis for mechanoenvironment-targeted therapy of tumors.

Objective    To investigate the characteristics and prognostic value of cellular immune function in severe patients with coronavirus disease 2019 (COVID-19). Methods    A cohort study was conducted to collect the clinical data of 119 severe patients admitted to the Renmin Hospital of Wuhan University (Eastern District) including 60 males (50.4%) and 59 females (49.6%), with an average age of 60.9±14.2 years. The primary endpoint of follow-up was death in the hospital, and the disease outcome classification was the secondary endpoint of follow-up within 30 days after admission. We analyzed the correlation between cellular immune function and COVID-19 prognosis. Results     A total of 22 patients died during this process, and 47 patients were severe/critical during the follow-up period. The counts of CD3+, CD4+, CD8+, and CD19+ in the primary endpoint events were significantly different between the survival group and the death group (all P<0.05). The counts of CD3+, CD4+, CD8+, CD19+ in the secondary endpoint events were significantly different between the normal group and the severe/critical group (all P<0.05). The results of the receiver operating characteristic (ROC) curve showed that the area under the cellular immune function curve of dead patients and severe/critical patients had good predictive value (all P<0.05). Conclusion    Cell immune function has good clinical and prognostic value for COVID-19.

Objective To develop a willpower scale for Chinese civil pilots.Methods 695 civil aviation pilots were collected by stratified random sampling based method on different positions.Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to analyzed the data and tested the reliability and validity of scale.Results The scale consisted of 16 items and 4 dimensions (pressure resistance,self-control,insist and decisiveness).4 dimensions explained 59.978% of the total variance.The Cronbach's α coefficient of full scale was 0.800,and the Cronbach's α coefficient of each factors were from 0.715 to 0.783.Coefficient of stability of the scale was beyond 0.805 (P<0.01).The correlation coefficient among each dimensions were from 0.050 to 0.366 (P<0.01),and the coefficient between each dimensions and the total score were from 0.565 to 0.699(P<0.01) and criterion validity of the questionnaire was 0.655 (P<0.01).Confirmatory factor analysis showed that the fitting effect of the four factors model was optimal (GFI=0.909,IFI=0.948,TLI=0.934,CFI=0.946,RMSEA=0.054).Conclusion The scale meets the requirements of psychological surveying,and it can be used as an effective tool for willpower of Chinese civil pilots.

OBJECTIVE: To investigate the job satisfaction status and its influencing factors in civil aviation pilots in a domestic airline. METHODS: A total of 422 civil aviation pilots of an airline were selected by the stratified random sampling method and investigated by Civil Aviation Pilots' Job Satisfaction Scale. Their job satisfaction situation and influencing factors were analyzed. RESULTS: The total score of job satisfaction of research objects was( 3. 0 ± 0. 5). The median and the quartile of the work arrangement,physical environment,salary and relationship with colleague were 2. 0( 1. 2),2. 2( 1. 0),3. 4( 1. 0) and 4. 0( 1. 0) respectively. The results of ordered multivariate logistic regression analysis showed that the salary satisfaction in pilots with length of service over 10. 0 years was higher than that of pilots with service length over1. 0 year( P < 0. 05),while the satisfaction of physical environment and work arrangement in pilots with service length over10. 0 years were lower than those with service length over 1. 0 year( P < 0. 01). The salary satisfaction of captain and captain instructors were higher than that of pilots and copilots( P < 0. 05),while the satisfaction of physical environment and work arrangement captain and captain instructors were lower than that of pilots and copilots( P < 0. 05). The satisfaction of work arrangement in married pilots was lower than that of unmarried pilots( P < 0. 05). CONCLUSION: The marital status,service length and job title were the major influencing factors of job satisfaction in civil aviation pilots.

Objective To study the relationship between the DNA content of chondrocytes in the costal cartilage and postmortem interval in putrefactive rat cadavers.Methods Nuclear DNA wag visualized by modified Feulgen's staining method.DNA content of ehondrocytes in the costal cartilage was semi-quantita tively determined by a computerized image analysis system in rats within 35d postmortem.Results Staining intensity of the nuclei was gradually reduced within from 1d to 28d postmortem.The nuclej could not be detected at 35d.The DNA content of chondrocytes decreased time-dependently within 28 days after death as determined semi-quantitatively,which revealed a linear relationship between DNA content and postmortem interval.Conclusion DNA content of chondrocytes in the costal cartilage reduces time-dependently with the extension of postmortem interval.

[Objective] To study the correlation between kidney cell DNA degradation and postmortem interval within the span of 6-48 hour after the subject rats′ death.[Methods] To select 18 healthy mature female SD rats and equally divide them into 6 groups.To execute the rats with cervical spine articulation and put the rats under the incubator temperature of 25.1℃ (the average temperature of the 5 previous Decembers in Guangzhou prefecture).Sample kidney tissue from the rat separately 0 hour,6 hours,12 hours,24 hours,36 hours,48 hours,and 60 hours after the rats′ execution to prepare monoplast suspension,which is committed to comet assay.The comet images were captured by fluorescence CCD.Kinetic Comet 4.0 software was used to analyze images.Relevant data were collected by kinetic Comet 4.0 software and were subjected to Kruskal-Wallis test.[Results] Within the postmortem interval of 6-48 h,the number of SD rat kidney cell DNA fragments increased as the postmortem interval lengthens.So did the comet tail length.The Oliver tail moment and tail DNA of comet also showed sign of increase in positive proportion to the postmortem interval (their values corresponding to 60-hour-postmortem-interval were not obtainable.Kruskal-Wallis test indicated:the discrepancies of TL among the 6 groups were all significant (P ＜ 0.01).The difference of TM between 6 h group and 12 h group was not significant (P ＞ 0.05).The difference of TM between 24 h and 36 h was significant (P ＜ 0.05).The difference of TDNA among 6 h,12 h,and 36 h groups were not significant (P ＞ 0.05).The difference of TDNA between 36 h and 48 h was significant (P ＜ 0.05).[Conclusion] Degradation of nuclear DNA of the rat kidney cells increases as the postmortem interval lengthens and comet assay may provide important empirical evidence for determining the postmortem interval.

OBJECTIVE: To optimize the extraction process of Xiaozheng plaster, a traditional Chinese medicine. METHODS: Xiaozheng plaster was prepared by water extraction and alcohol precipitation method with stachydrine content in water and the yield of powdered extract as evaluation indexes. The orthogonal test was carried out to optimize the reasonable parameters of the extraction process. RESULTS: The optimal extraction process for the prescription was adding 12-fold of water and decocting for 90 minutes at each time for three times altogether with alcohol precipitation concentration at 45%. CONCLUSION: The extractive condition can be optimized through visual analysis and the preparation technology is feasible.

Objective To study the effect of psychological intervention on quarantined pilot students during the influenza A (H1N1) pandemic. Methods During quarantine,psychological intervention,including Critical Incident Stress Debriefing (CISD) and individual interview,are given to 37 pilot students who just went back from the epidemic area in USA. Psychological tests,including Self-Rating Anxiety Scale (SAS)test and Self-Rating Depression Scale (SDS)test on the 3rd day of quarantine,and Symptom Check List-90 (SCL-90) test before and after the quarantine,are carried out. Results Psychological health level of the quarantined students is higher than that of national college students. And the psychological health level of the students is improved after the quarantine. Conclusion Appropriate psychological intervention can transform critical incident into the resource of promoting growing up for students.