RESUMO
The ability to rapidly and reliably screen for bacterial vaginosis (BV) during pregnancy is of great significance for maternal health and pregnancy outcomes. In this proof-of-concept study, we demonstrated the potential of carbon nanotube field-effect transistors (NTFET) in the rapid diagnostics of BV with the sensing of BV-related factors such as pH and biogenic amines. The fabricated sensors showed good linearity to pH changes with a linear correlation coefficient of 0.99. The pH sensing performance was stable after more than one month of sensor storage. In addition, the sensor was able to classify BV-related biogenic amine-negative/positive samples with machine learning, utilizing different test strategies and algorithms, including linear discriminant analysis (LDA), support vector machine (SVM), and principal component analysis (PCA). The biogenic amine sample status could be well classified using a soft-margin SVM model with a validation accuracy of 87.5%. The accuracy could be further improved using a gold gate electrode for measurement, with accuracy higher than 90% in both LDA and SVM models. We also explored the sensing mechanisms and found that the change in NTFET off current was crucial for classification. The fabricated sensors successfully detect BV-related factors, demonstrating the competitive advantage of NTFET for point-of-care diagnostics of BV.
Assuntos
Nanotubos de Carbono , Vaginose Bacteriana , Algoritmos , Análise Discriminante , Feminino , Humanos , Máquina de Vetores de Suporte , Vaginose Bacteriana/diagnóstico , Vaginose Bacteriana/microbiologiaRESUMO
The microbial mechanisms of carbon removal in subsurface flow wetlands were studied, in one wetland with plants and one without plants. Particular emphasis was given to the influence of plants in the treatment process. Wetlands without plants showed higher carbon removal than those with plants, 63% and 51%, respectively (p < 0.05). Molecular analysis of the bacterial diversity, growth rates and specific microbial activities showed that the two wetlands were different, especially towards the outlet of the two systems. Sulphate reducers and methanogens were found in both wetlands, and they are thought to be the main removers of soluble organic carbon in these two systems.