Leveraging Cas13a's trans-cleavage on RNA G-quadruplexes for amplification-free RNA detection.

In this study, we investigated Cas13a's efficacy in trans-cleaving RNA G-quadruplexes (rG4s) as an alternative to ssRNA reporters in CRISPR-Cas13a diagnostics. Our findings demonstrate enhanced efficiency due to the structural arrangement of rG4s. Implementing a simplified CRISPR-Cas13a system based on rG4, we identified SARS-CoV-2 infections in 25 patient samples within 1 hour without target pre-amplification.

A Novel Data Augmentation Method for Improving the Accuracy of Insulator Health Diagnosis.

Performing ultrasonic nondestructive testing experiments on insulators and then using machine learning algorithms to classify and identify the signals is an important way to achieve an intelligent diagnosis of insulators. However, in most cases, we can obtain only a limited number of data from the experiments, which is insufficient to meet the requirements for training an effective classification and recognition model. In this paper, we start with an existing data augmentation method called DBA (for dynamic time warping barycenter averaging) and propose a new data enhancement method called AWDBA (adaptive weighting DBA). We first validated the proposed method by synthesizing new data from insulator sample datasets. The results show that the AWDBA proposed in this study has significant advantages relative to DBA in terms of data enhancement. Then, we used AWDBA and two other data augmentation methods to synthetically generate new data on the original dataset of insulators. Moreover, we compared the performance of different machine learning algorithms for insulator health diagnosis on the dataset with and without data augmentation. In the SVM algorithm especially, we propose a new parameter optimization method based on GA (genetic algorithm). The final results show that the use of the data augmentation method can significantly improve the accuracy of insulator defect identification.

Phosphine-Catalyzed [3 + 2] Cycloaddition Reaction of α-Diazoacetates and ß-Trifluoromethyl Enones: A Facile Access to Multisubstituted 4-(Trifluoromethyl)pyrazolines.

A novel phosphine-catalyzed [3 + 2] cycloaddition of α-diazoacetates and ß-trifluoromethyl enones has been developed that provides facile access to multisubstituted 4-(trifluoromethyl)pyrazolines in good to excellent yields at room temperature. In addition, a tandem [3 + 2] cycloaddition/Michael addition is also presented.