Objective To evaluate the clinical application of Straumman implant system in the upper anterior region.Methods 23 patients were implanted with 28 Straumman implants.Follow up of clinical observation and maitenance began after final crown restored.Bone resorption mesial and distal to the implant were recorded by periodical X-ray check.Soft tissue was observed and analyzed according to Jemet papilla index.Results Total survival rate of all the 28 implats was 100％.Alveolar bone resorptions between mesial part of the implant and distal part with loading after 0.5 year,1 year,2 years and 4 years had no stastical significance(t =0.689,0.686,0.694,0.705,all P ＞0.05).Interdental papillae around implant supported crown gained recovery after 2 years.Conclusion Optimal treatment result was gained through Straumman implants applied in the maxillarv anterior region with satifactory aesthetic expectation.Its further use was predictable and advisable.

Objective To explore the application value of magnetic resonance molecular functional imaging diffusion weighted imaging(DWI) in the identification of pancreatic carcinoma and mass-type pancreatitis of animal model.Methods Each 8 cases of laboratory pancreatic head transplantation tumor model,chronic mass-type pancreatitis model and normal rabbits were selected and performed the MR DWI molecular functional imaging,the b values were 333,667,1 000 s/mm2 respectively.The apparent diffusion coefficients(ADC) of pancreatic carcinoma model,mass-type pancreatitis model and normal pancreas under different b values were observed.Then the change situation of ADC values of pancreatic carcinoma model,mass-type pancreatitis model and normal pancreas under different b values and difference of ADC(DADC) was analyzed.Moreover the differences in molecular diffusion,tissue perfusion among various groups were observed.Results Throughout the study period,the mortality rate of pancreatic head transplantation tumor model was 50%;the mass-type pancreatitis model and 8 normal rabbits were normally survival.The ADC value of pancreatic carcinoma under the same b value was significantly lower than that of chronic inflammation and normal pancreas area.The ADC value in each group was decreased with the increase of b value,and there was significant difference in ADC value when the b value was 333 s/mm2(F=6.662,P=0.014),in the pairwise comparison among groups,the difference between pancreatic cancer and pancreatitis (t=6.773,P=0.003) and between pancreatic cancer and normal pancreas(t=5.883,P=0.016) had statistical significance (P<0.05).The b value was increased,DADC was smaller,the difference change of DADC between pancreatic cancer area and chronic pancreatitis mass area,between pancreatic cancer area and normal pancreatic head area had statistical significance (P<0.05).Conclusion Rationally selecting the molecular functional imaging DWI technology of b value can better distinguish pancreatic cancer from mass-type pancreatitis,which may be promoted and applied in the evaluation of animal pancreatic head cancer model.

Objective:To identify the genome-wide characteristics and variations of the novel coronavirus 2019(2019-nCoV) by combining high-throughput sequencing and bioinformatics techniques, to type and trace the virus.Methods:Pharyngeal swab sample of one 2019-nCoV infection case imported from Weihai city was selected for 2019-nCoV whole-genome sequence capture and NGS high-throughput sequencing. The obtained sequencing data were sequenced and analyzed using virus mutation analysis software, we classify viruses and build phylogenetic trees to track their potential sources.Results:The complete genome sequence of 2019-nCoV was obtained, with a total length of 29 808 bp and an average sequencing depth of 5 013.11×. A total of 51 nucleotide mutations were found in 8 coding regions (ORF1ab, S, ORF3a, E, M, ORF6, ORF7a and N). The result of virus typing showed that the virus belonged to Omicron BA.2. Evolutionary analysis showed that the virus sequence was in the same clade as the reference strains from Japan.Conclusions:The sequencing method and analysis result established in this study can be used for mutation analysis of 2019-nCoV and case tracing, which is of great significance for the prevention and control of COVID-19.