African swine fever virus(ASFV)I177L gene deletion vaccine is one of the key directions of African swine fever(ASF)live attenuated vaccine research and development.In order to effec-tively distinguish between the wild-type ASFV strain and the I177L gene-deleted strain,specific primers and probes were designed based on ASFV B646L and I177L genes,respectively.After screening and optimization,a duplex real-time PCR method was developed that can simultaneously detect these two genes.The results showed that ASFV B646L and I177L genes were detected spe-cifically and simultaneously by the method developed without cross-reactions with porcine circovir-us type 2,Seneca virus A,classical swine fever virus,foot-and-mouth disease virus,porcine respira-tory and reproductive syndrome virus.The detection limits of the duplex real-time PCR for recom-binant plasmids pUC57-B646L and pUC57-I177L were 1×103 copies/mL.The intra-and inter-as-say coefficients of variation were less than 4％,respectively.Detection of 122 pork and pork prod-ucts using the duplex real-time PCR developed and the real-time PCR recommended by WOAH showed that the coincidence rates of the two methods for B646L gene detection was 100％with two amplification curves appeared in the positive results of the established methods.The method established in this study can be used for the detection of ASFV I177L gene deletion strains,which provides technical support for ASF surveillance and epidemiological investigation.

Objective To investigate the prevalence of temporomandibular disorders(TMD) symptoms,psychological distress and sleep quality in a population of Chinese university students,and discuss the relationship between psychological distress,sleep quality and TMD symptoms.Methods A total of 898 stomatological university students from 5 Chinese universities(342 males and 556 females with a mean age of 20.5 years) were included in the study.Self-reported TMD symptoms using diagnostic criteria for temporomandibular disorders symptom questionnaire were collected.Depression,anxiety and stress scales-21(DASS-21) and Pittsburgh sleep quality index(PSQI) were used to measure psychological distress and sleep quality.Results 61.9％ (556/898) of the stodents had TMD symptoms.The most common symptoms were pain and clicking of joint,with a prevalence of 42.3％ (380/898) and 34.2％ (307/898),respectively.The prevalence of depression,anxiety,stress and sleep quality among the students who had TMD symptoms was 33.5％(186/556),63.1％(351/556),29.5％(164/556) and 30.2％(243/556),respectively,which was significantly higher than those who had no TMD symptoms(24.3％ [83/342],48.5％ [166/342],21.6％[74/342] and 21.9％[75/342])(P＜0.05).Stepwise logistic regression analysis demonstrated that anxiety (OR 1.57,95％CI 1.14-2.15) and female(OR 1.57,95％CI 1.19-2.08) were possible risk indicators for TMD symptoms(P＜0.05).Conclusions Chinese university students reported a high prevalence of TMD symptoms,which may have a correlation with psychological distress symptoms such as anxiety.