Objective: To evaluate a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and compare it with RT-PCR. Methods: We designed primers specific to the orf1ab and S genes of SARS-CoV-2. Total viral RNA was extracted using the QIAamp Viral RNA Mini Kit. We optimized the RT-LAMP assay, and evaluated it for its sensitivity and specificity of detection using real-time turbidity monitoring and visual observation. Results: The primer sets orf1ab-4 and S-123 amplified the genes in the shortest times, the mean (±SD) times were 18 ± 1.32 min and 20 ± 1.80 min, respectively, and 63 C was the optimum reaction temperature. The sensitivities were 2 Â 10 1 copies and 2 Â 10 2 copies per reaction with primer sets orf1ab-4 and S-123, respectively. This assay showed no cross-reactivity with 60 other respiratory pathogens. To describe the availability of this method in clinical diagnosis, we collected 130 specimens from patients with clinically suspected SARS-CoV-2 infection. Among them, 58 were confirmed to be positive and 72 were negative by RT-LAMP. The sensitivity was 100% (95% CI 92.3%e100%), specificity 100% (95% CI 93.7% e100%). This assay detected SARS-CoV-2 in a mean (±SD) time of 26.28 ± 4.48 min and the results can be identified with visual observation. Conclusion: These results demonstrate that we developed a rapid, simple, specific and sensitive RT-LAMP assay for SARS-CoV-2 detection among clinical samples. It will be a powerful tool for SARS-CoV-2 identification, and for monitoring suspected patients, close contacts and high-risk groups. C.

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The mechanisms of refractive index change in poly(methyl methacrylate) by frequency doubled femtosecond laser pulses are investigated. It is demonstrated that positive refractive index modificaton can be caused by a combination of depolymerization and crosslinking.

Inspired by nature, superhydrophobic surfaces have attracted increasing research interest owing to the wide range of applications such as fluid drag reduction, corrosion resistance, and self-cleaning [1][2][3][4]. Developments in designing and preparing superhydrophobic surfaces have shown promising anti-icing performance [5], creating an opportunity to prevent the wings of aircraft or electrical insulators from icing [6,7]. Today, superhydrophobic surfaces can be generated by techniques such as templating, colloidal assembly, physical vapour deposition, chemical vapour deposition, hydrothermal, electrochemical deposition, etching, plasma treatment, and laser processing [8,9]. Among these methods, laser processing is a