ABSTRACT
Objective To develop a novel gold immunochromatographic double antibody sandwich assay for the detection of SARS-CoV-2 antigen, and to evaluate the performance of major reagents. Methods Potassium carbonate, large colloidal gold and SARS-CoV-2 antibody were used to prepare colloidal gold antibody markers, SARS-CoV-2 antibody concentration was optimized to prepare the binding pad, SARS-CoV-2 antibody and goat anti-mouse IgG were coated on nitrocellulose membrane as detection line and quality control line, according to the process requirements to assembly the assay. The minimum detection limit, cross-reactivity, accelerated stability test and clinical evaluation of the antigen detection reagent were determined. Results The minimum detection limit of SARS-CoV-2 inactivated virus was 3. 3×10~2 TCID50/ml, and no cross-reaction was found in the samples containing 10 common pathogens. The results of 37 °C high temperature accelerated test for 28 d showed high stability of the reagent. The sensitivity, specificity and total coincidence rate were 92. 00%, 100. 00% and 98. 67% and the Kappa value of concordance test was 0. 939, P＜0. 01. Conclusion The developed antigen detection assay has high sensitivity and specificity, which is also simple to operate in a short time. It can be used as a rapid detection method for large-scale screening of novel coronavirus.
ABSTRACT
The dried root of Glehnia littoralis is a traditional Chinese herbal medicine mainly used to treat lung diseases and plays an important role in fighting coronavirus disease 2019 pneumonia in China. This study focused on the key enzyme gene GlPS1 for furanocoumarin synthesis in G. littoralis. In the 35S:GlPS1 transgenic Arabidopsis study, the Arabidopsis thaliana-overexpressing GlPS1 gene was more salt-tolerant than Arabidopsis in the blank group. Metabolomics analysis showed 30 differential metabolites in Arabidopsis, which overexpressed the GlPS1 gene. Twelve coumarin compounds were significantly upregulated, and six of these coumarin compounds were not detected in the blank group. Among these differential coumarin metabolites, isopimpinellin and aesculetin have been annotated by the Kyoto Encyclopedia of Genes and Genomes and isopimpinellin was not detected in the blank group. Through structural comparison, imperatorin was formed by dehydration and condensation of zanthotoxol and a molecule of isoprenol, and the difference between them was only one isoprene. Results showed that the GlPS1 gene positively regulated the synthesis of coumarin metabolites in A. thaliana and at the same time improved the salt tolerance of A. thaliana.
Subject(s)
COVID-19ABSTRACT
The COVID-19 virus has swept the world and brought great impact to various fields, gaining wide attention from all walks of life since the end of 2019. At present, although the global epidemic situation is leveling off and vaccine doses have been administered in a large amount, confirmed cases are still emerging around the world. To make up for the missed diagnosis caused by the uncertainty of nucleic acid polymerase chain reaction (PCR) test, utilizing lung CT examination as a combined detection method to improve the diagnostic rate becomes a necessity. Our research considered the time-consuming and labor-intensive characteristics of the traditional CT analyzing process, and developed an efficient deep learning framework named CSGBBNet to solve the binary classification task of COVID-19 images based on a COVID-Seg model for image preprocessing and a GBBNet for classification. The five runs with random seed on the test set showed our novel framework can rapidly analyze CT scan images and give out effective results for assisting COVID-19 detection, with the mean accuracy of 98.49 ± 1.23%, the sensitivity of 99.00 ± 2.00%, the specificity of 97.95 ± 2.51%, the precision of 98.10 ± 2.61%, and the F1 score of 98.51 ± 1.22%. Moreover, our model CSGBBNet performs better when compared with seven previous state-of-the-art methods. In this research, the aim is to link together biomedical research and artificial intelligence and provide some insights into the field of COVID-19 detection.