Search

The consumption of water and food contaminated by pathogens is a major cause of numerous diseases and deaths globally. To control pathogen contamination and reduce the risk of illness, a system is required that can quickly detect and monitor target pathogens. We developed a simple and reproducible strategy, termed three-way junction (3WJ)-induced transcription amplification, to detect target nucleic acids by rationally combining 3WJ-induced isothermal amplification with a light-up RNA aptamer. In principle, the presence of the target nucleic acid generates a large number of light-up RNA aptamers (Spinach aptamers) through strand displacement and transcription amplification for 2 h at 37 °C. The resulting Spinach RNA aptamers specifically bind to fluorogens such as 3,5-difluoro-4-hydroxybenzylidene imidazolinone and emit a highly enhanced fluorescence signal, which is clearly distinguished from the signal emitted in the absence of the target nucleic acid. With the proposed strategy, concentrations of target nucleic acids selected from the genome of Salmonellaenterica serovar Typhi (S. Typhi) were quantitatively determined with high selectivity. In addition, the practical applicability of the method was demonstrated by performing spike-and-recovery experiments with S. Typhi in human serum. [ABSTRACT FROM AUTHOR]

A levelized cost of energy (LCOE) is a methodology for comparing power generation costs in the transition to renewable energy (RE). However, the major limitation of evaluating RE based on the LCOE is that it does not consider indirect costs, such as the environmental and curtailment effect. This paper proposes the real LCOE (rLCOE) approach that accounts for indirect and direct generation costs. The mathematical approach to estimating indirect costs is derived from economic theory. The indirect effects, which quantify all benefits generated due to RE, is related to the variability of the share RE in the energy generation mix. The rLCOE enhances the accuracy of the economic comparison of power generation costs and the derivation of the optimal quantities of RE because external effects are incorporated into the LCOE principles. This approach has taken into account electricity demand, fuel prices, and environmental costs for each energy source to adequately compare generation costs. Simulations have been performed to demonstrate the application of the rLCOE approach in the Korean power market. Here, the unit variation of costs with the RE share were analyzed. The results show that indirect cost savings of an additional unit of RE begin to fall in scenario 3 in contrast to the result of LCOE approach indicating higher generation costs with RE share, especially, the proportion of RE in the generation mix is higher than 20%. Thus, the optimal power generation can be evaluated using the rLCOE approach. [ABSTRACT FROM AUTHOR]