Objective:To construct a recombination plasmid containing a kanamycin resistance gene,the upstream and downstream fragment of luxS of Streptococcus mutans so that luxS can be knock out by transforming the plasmid into S.mutans later.Methods:Kanamycin resistance gene,the upstream and downstream of luxS were cloned respectively by using plasmid pEGFP-N1 and DNA of Streptococcus mutans as template.Then the genes were ligated into Multiple Cloning Site(MCS) of vector pMD19-T in certain order and transformed into E.coli Competent Cells.Finally transformants were selected for resistance to kanamycin and ampicillin.Results:Kanamycin resistance gene and the upstream and downstream of luxS were successfully ligated into accurate enzyme digestion site of vector pMD19-T,and restriction digests analysis and sequencing result was correct.Conclusion:LuxS gene knock-out of Streptococcus Mutans recombinant plasmid is constructed and built a base of constructing Streptococcus Mutans luxS mutans in the future.

Vital pulp therapy aims to maintain healthy pulp tissue as much as possible to improve the long-term survival of teeth. It has limited indications and uncertain curative effects. The pathological changes in inflamed pulp are the histological basis for the determination of treatment strategies and the treatment outcome; however, pulp sensitivity testing cannot reflect the actual histological status of the pulp. With the development of basic and clinical research on vital pulp therapy, the innovation of modern diagnostic and therapeutic technology and capping material, vital pulp therapy can be used as a treatment of teeth on which it was previously thought pulpectomy was necessary. Based on the evidence-based literature, this paper analyzes and summarizes the pathological changes of pulpitis and clinical research on the treatment of pulpitis. Vital pulp therapy can be a treatment for mature teeth with carious exposure and symptoms of irreversible pulpitis if comprehensive applications, including laser Doppler flowmetry, tissue oxygen monitoring, magnetic resonance imaging and microscopy, are used to determine the degree of pulp retention and if infection control and the use of biocompatible capping material are emphasized. In the future, it will be necessary to improve the success rate of vital pulp therapy for the treatment of pulpitis through research on the mechanism of pulp repair and regeneration, the precise diagnosis of pulpitis, and the development of pulp capping materials.

Objective To investigate the characteristics and influencing factors of mental health status of permanent residents in Yichang, Hubei Province. Methods A total of 9 576 permanent residents aged 18 years and older from Yichang City were selected by a multistage random sampling method between June and October 2022. The PHQ-9 was used to assess the residents’ depressive symptoms, the GAD-7 was used to assess their anxiety symptoms, the ISI was used to assess their insomnia status, and the PCL-5 was used to assess their stress status. The influence factors of depression and anxiety were analyzed using χ2 test and logistic regression. Results A total of 9 122 valid questionnaires were completed. The detection rate of depression, anxiety, insomnia, and stress symptoms were 29.98%, 19.03%, 11.97% and 1.58%, respectively. Gender, education level, monthly family income, self-rated health status, mental health literacy level, total GAD-7 score, total ISI score, and total PCL-5 score were the main factors that caused residents' anxiety symptoms, while gender, education level, self-rated health status, total PHQ-9 score, total ISI score, and total PCL-5 score were the main factors that caused residents' anxiety symptoms. Conclusion The prevalence of depression and anxiety is high among the permanent residents in Yichang, while the situation of insomnia and stress is relatively good. Measures such as improving the level of mental health literacy can be taken to improve mental health level of residents in Yichang.