An enhanced gold immunochromatographic assay ( GICA ) with simplicity, rapidity and high sensitivity was developed to detect imidaclothiz by using the high affinity between biotin and streptavidin. The 13-nm AuNPs were double-labeled with anti-imidaclothiz antibody and biotinylated DNA, and the 41-nm AuNPs were labeled with streptavidin to prepare an enhanced gold immunochromatographic test strip for imidaclothiz. The working conditions of the strip were systematically optimized, and the sensitivity, specificity, precision and accuracy were assessed by testing the cross-reactivity ( CR) , spiked recovery and validation with high performance liquid chromatography ( HPLC) . Under the optimal conditions, the detection could be completed in 10 min with visual result, and the limit of detection ( LOD ) was 25 ng/mL. The analysis showed no cross-reactivity with analogues of imidaclothiz except for imidacloprid. The detection results of GICA agreed with the spiked concentrations of imidaclothiz at spiked levels of 0 . 05 , 0 . 5 and 5 μg/g in river water, rice, cucumber, tomato, pear, cabbage and apple samples. The detection results of GICA for imidaclothiz in unknown concentration river water and pear samples were consistent with that of HPLC.

Objective:To analyze differences in peripheral blood T-cell receptor(TCR)genes in patients with viral pneumo-nia by single cell sequencing,and to explore its possible pathogenesis.Methods:Data in NCBI database was obtained,and case and control groups were set up for experiments.Single cell sequencing data was analyzed of by R language in RStudio software,tables and images were plotted,and finally conclusions were drawn.Results:There was a significant difference in TCRs between case and healthy control groups.Frequency of use of V and J gene fragments of TCR α and β chains were analyzed,in which frequency of use of TRAV1-2,TRAV29/DV5,TRAJ33,TRAJ48,TRBV20-1,TRBV2,TRBJ2-3 and TRBJ1-1 genes were significantly higher in case group than in control group(P<0.05).Further V-J gene combination analysis showed that the most frequent use of α-chain V-J pairs in case group was TRAV1-2-J33,most frequent use of β-chain V-J pairs was TRBV20-1-J2-1,most frequent use of αβ double-chain V-J pairs was TRAV30-J24-TRBV3-1-J2-7.Conclusion:Peripheral blood TCR genes are significantly altered in patients with viral pneu-monia,which may be related to immunopathogenesis of virus.

Objective:Using single cell sequencing to analyze the characteristics of the immune repertoire of SARS-CoV-2 pa-tients at different infection stages,and to explore the possible pathogenesis.Methods:Obtaining data in the NCBI database,and healthy control,progression and convalescence groups were set up.Analysis of single cell sequencing data by RStudio,Origin,Hipliot and Excel software.Results:TCR plays an important role in antigen recognition and virus clearance.Characteristics of the three immune repertoires are very different.The number of clones exceeded 26.92%.The length distribution of α chain CDR3 was con-centrated on 14 amino acids,while β-chain was concentrated on 15 amino acids.The frequency of gene fragments in V and J regions were different,and the frequency of TRAV13-1,TRAJ20,TRBV20-1 and TRBJ2-1 were statistically significant(P<0.05).Further V-J gene combination analysis showed that there were significant differences in the frequency of single chain V-J between the control group and the progression group,the control group and the rehabilitation group(P<0.05).The highest frequency of αβ double chain V-J in the control group was TRAV19-J34-TRBV4-1-J2-1,the highest frequency of αβ double-stranded V-J in the progression group was TRAV12-1-J30-TRBV19-1-J2-1,and the highest frequency of αβ double chain V-J in the convalescence group was TRAV12-2-J52-TRBV7-9-J1-5.Conclusion:This study analyzes the global characteristics of T cells in the immune repertoire,which is helpful to understand the pathogenesis of SARS-CoV-2 patients,timely and effective treatment of patients in the early stages of infection.

Objective: Comparing the benefit of Abidor, lopinavir/ritonavir and recombinant interferon α-2b triple combination antiviral therapy and lopinavir/ritonavir and interferon dual combination antiviral therapy to hospitalized novel coronavirus pneumonia 2019 in Zhejiang province. Methods: A multi-center prospective study was carried out to compare the effect of triple combination antiviral therapy with dual combination antiviral therapy in 15 medical institutions of Zhejiang Province. All patients were treated with recombinant interferon α-2b (5 million U, 2 times/d) aerosol inhalation. 196 patients were treated with abidol (200 mg, 3 times/d) + lopinavir / ritonavir (2 tablets, 1 time/12 h) as the triple combination antiviral treatment group. 41 patients were treated with lopinavir / ritonavir (2 tablets, 1 time/12 h) as the dual combination antiviral treatment group. The patients who received triple combination antiviral therapy were divided into three groups: within 48 hours, 3-5 days and > 5 days after the symptom onset. To explore the therapeutic effects of triple combination antiviral drugs and dual combination antiviral drugs, as well as triple combination antiviral drugs with different antiviral initiate time. SPSS17.0 software was used to analyze the data. Results: The time of virus nucleic acid turning negative was (12.2 ± 4.7) days in the triple combination antiviral drug group, which was shorter than that in the dual combination antiviral drug group [(15.0 ± 5.0) days] (t = 6.159, P < 0.01 ). The length of hospital stay [12 (9, 17) d] in the triple combination antiviral drug group was also shorter than that in the dual combination antiviral drug group [15 (10, 18) d] (H = 2.073, P < 0.05). Comparing the antiviral treatment which was started within 48 hours, 3-5 days and > 5 days after the symptom onset of triple combination antiviral drug group, the time from the symptom onset to the negative of viral shedding was 13 (10,16.8), 17 (13,22) and 21 (18-24) days respectively (Z = 32.983, P < 0.01), and the time from antiviral therapy to the negative of viral shedding was (11.8±3.9) , (13.5±5.1) and (11.2±4.3) d. The differences among the three groups were statistically significant (Z=32.983 and 6.722, P<0.01 or<0.05). Conclusions The triple combination antiviral therapy of Abidor, Lopinavir/Litonavir and recombinant interferon α-2b showed shorter viral shedding time and hospitalization time compared with the dual combination antiviral therapy. The earlier the time to initiate triple antiviral treatment, the shorter the time of virus shedding.