Objective To evaluate the risk of disease of Vibrio parahaemolyticus in aquatic products of raw food animals for population in guangzhou,and determine risk management points. Methods VP quantitative detection was carried out in aquatic products of raw food animals sold in Guangzhou from 2009 to 2022.sQMRA was applied to assess Vibrio parahaemolyticus risk of aquatic products of raw food animals. According to stratified analysis based on the pollution of Vibrio parahaemolyticus and evaluation results,carry out risk management and analysis. Results Among the 98 samples were detected positive of VP from 1 343 samples from 2009 to 2022 , with an overall positive rate of 7.30%.The number of Vibrio parahaemolyticus infection cases caused by eating aquatic products of raw food animals in Guangzhou was 3012. If the proportion of raw food is reduced , the number of Vibrio parahaemolyticus infection cases will be significantly reduced. The number of cases caused by eating raw fash will be reduced from 2128 to 217.The detection rate of Vibrio parahaemolyticus in raw fresh water products was much higher than that in marine products. The probability of infection in the population was higher. The number of cases caused by eating raw fash was the highest.The detection rate of Vibrio parahaemolyticus was higher in raw crustaceans and molluscs. The incidence of Vibrio parahaemolyticus infection cases caused by eating raw fash in the four quarters varied from high to low as such sequence ,4.93×10^-5 in the three quarters , 2.53×10^-5 in the second quarter , 2.40×10^-5 in the first quarter ,1.77×10^-5 in the fourth quarter . Conclusion The risk of disease of Vibrio parahaemolyticus in aquatic products of raw food animals was higher. The public health education should be done well. Aquatic products should be cooked thoroughly before eating . Reduce the intake of raw aquatic products and avoid cross contamination. Focus on the risks of summer and autumn seasons and seafood such as crustaceans and molluscs. Concentrate on scientific research on Vibrio parahaemolyticus pollution of fresh water products.

Objective To understand phthalic acid esters pollution of daily consumed food in Guangzhou City，and evaluate the hazard of phthalic acid esters exposure in residents dietary. Methods Detected the content of phthalic acid esters in 10 types of food by gas chromatography-mass spectroscopy（GC-MS）methods .It combined with a survey on dietary nutrients intake of Guangzhou residents was conducted．Hazard index on the dietary exposure assessment of chemicals in food was applied. Results It showed that the highest levels of DBP，DEHP and DIBP，from the mixed diet samples in Guangzhou were 1.256，1.418，0.576 mg/kg respectively；and the exposure level of DBP，DEHP and DIBP were 2.431、5.981、2.408μg/kg.d ;HQ was respectively 0.243、0.125、0.025. HI was 0.393. Conclusion The dietary contamination of phthalic acid esters for Guangzhou was kept at a low level.But the pollution of 3 kinds of mixed samples such as meats，eggs，aquatic and products may be a certain risk of health that should attract more attention.

Objective: To explore the biomechanical characteristics of short implants with different diameters in mandibular molars with severe jaw absorption, and to provide theoretical basis for the application of short implants in mandibular molar area. Methods: CBCT data of patient were imported into Mimics and 3-Matic, and the finite element model of mandibular second molar repaired with short implant with diameter of 5.5 mm or 6.5 mm and length of 7 mm was established. The data were imported into three-dimensional finite element analysis software Marc Mentat, and high or low density bone was set up. An axial or buccal load of 150 N was applied to simulate clinical situation. A total of 8 models were established. Cortical bone stress, cancellous bone strain and implant displacement were calculated and analyzed. Results: The cortical bone stress was concentrated in the neck of implant, and the cancellous bone strain was mainly distributed in the apical area of implant. The maximum values of cortical bone stress, cancellous bone strain and implant displacement were higher in buccal loading model than those in axial loading model, and they were higher in low density bone model than those in high density bone model under the same conditions. When the 5.5 mm diameter implant was loaded in buccal direction and the surrounding bone density was low, the maximum strain of cancellous bone was greater than the upper limit of physiological absorption of bone tissue 3 000 μstrain. Conclusion The application of short implants in mandibular molars with insufficient vertical bone mass is a feasible restoration scheme. But for patients with low bone mineral density, large diameter short implants can be appropriately selected, and the occlusal area and the cusp inclination can be appropriately reduced, so as to reduce the lateral force and obtain the stability and success of the implant in the short and long term.