Objective To define a suitable threshold setting for gross tumor volume (GTV)when using 18F-fluoro-deoxyglucose positron emission tomography and computed tomogram (PET/CT) for radiotherapy planning in Nasopharyngeal carcinoma(NPC).Methods Sixteen NPC patients respectively received PET/CT and MRI scan before their radiation treatment.All of the images were transferred to the radiotherapy planning system (TPS).MRI/CT-based primary GTV was defined as GTVf.Biological target volumes (BTVs) were derived from PET/CT-based GTVs of primary tumors.The BTVs were defined as the volumes when adjusting different percentage of the maximal standardized uptake value (SUVmax).GTVfs were compared with BTVs.The suitable threshold level (sTL) could be determined when BTV value and its morphology using a certain threshold level were observed to be the fittest GTVf.The suitable standardized uptake value (sSUV) was calculated as the sTL multiplied by the SUVmax.Results Our result demonstrated no single sTL or sSUV method could achieve an optimized volumetric match with the GTVf.The sTL was [20.93％±6.51％(15％-40％)],whereas the sSUV was [2.27±0.48(1.56-3.25)].The sTL was inversely correlated with the SUVmax sTL =-0.144ln(SUVmax) + 0.5548 (R2 =0.85,F =78.57,P＜0.01.The sSUV showed a linear correlation with the SUVmax sSUV =0.104(SUVmax) + 1.0398,(R2=0.75,F=41.88,P＜0.01).The sTL was not associated with the value of GTVf.Conclusions In PET/CT-based BTV for NPC,SUVmax threshold method is feasible.sTL is not a fixed value,which is correlated with the SUVmax instead of the value of tumor.

Abstract： Objective To analyze the first epidemic spread of the novel coronavirus Delta variant in China based on public security forensic perspective, investigate its transmission characteristics, contributing factors, and epidemiologic research experience, and provide a reference for the prevention and control of the epidemic caused by the novel coronavirus variant. Methods Based on the information that public security forensic experts obtained from front-line epidemiologic research, the gender, age, place of residence, transmission route and infectivity of the coronavirus disease 2019 （COVID-19） confirmed cases, asymptomatic infected persons and their close contacts in Guangzhou caused by the novel coronavirus Delta variant were analyzed. The basic reproduction number （R₀） during this epidemic in Guangzhou was calculated. Results Among the 153 cases infected with novel coronavirus Delta variant in the epidemic, 63 cases were male and 90 cases were female, their age ranging from 1 to 92 years, with a median age of 49 years. The main route of transmission was close contact, including dining together, co-living, and close contact in the same residential building. There were 31 cases of family clusters, 25 of which were in Liwan District. The epidemic lasted from May 26 to May 29, and the R₀ remained above 4.0. After May 30, R₀ began to decline and remained below 1.0 from June 7. Conclusion The novel coronavirus Delta variant is highly infectious, the crowd is generally susceptible to infection and family cluster cases are easy to occur. So, it is necessary to precisely prevent and control this strain. Public security forensic experts have both medical literacy and criminal investigation capabilities, they can play a more professional role in epidemic prevention and control.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; COVID-19 ; Child ; Child, Preschool ; China/epidemiology* ; Epidemics ; Female ; Humans ; Infant ; Male ; Middle Aged ; SARS-CoV-2 ; Young Adult

This study was to investigate the protective effect of paeoniflorin (PF) on hydrogen peroxide-induced injury. Firstly, "SMILES" of PF was searched in Pubchem and further was used for reverse molecular docking in Swiss Target Prediction database to obtain potential targets. Injury-related molecules were obtained from GeenCards database, and the predicted targets of PF for injury treatment were selected by Wayne diagram. For mechanism analysis, the protein-protein interactions were constructed by String, and the KEGG analysis was conducted in Webgestalt. Then, cell viability and cytotoxicity assay were established by CCK8 assay. Also, the experimental cells were allocated to control, model (200 μmol·L