No abstract

The ongoing novel coronavirus (COVID-19) outbreak as a global public health emergency infected by SARC-CoV-2 has caused devastating loss around the world. Currently, a lot of diagnosis methods have been used to detect the infection. The nucleic acid (NA) testing is reported to be the clinical standard for COVID-19 infection. Evidence shows that a faster and more convenient method to detect in the early phase will control the spreading of SARS-CoV-2. Here, we propose a method to detect SARC-Cov-2 infection within two hours combined with Loop-mediated Isothermal Amplification (LAMP) reaction and nanopore Flongle workflow. In this approach, RNA reverse transcription and nucleic acid amplification reaction with one step in 30 minutes at 60-65°C constant temperature environment, nanopore Flongle rapidly adapter ligated within 10 minutes. Flongle flow cell sequencing and analysis in real-time. This method described here has the advantages of rapid amplification, convenient operation and real-time detection which is the most important for rapid and reliable clinical diagnosis of COVID-19. Moreover, this approach not only can be used for SARS-CoV-2 detection but also can be extended to other respiratory viruses and pathogens.

According to the electromagnetic (EM) wave scattering field of charged spherical particles, we derived the amplitude ratio and phase difference of the transverse components of the scattered electric field. We found that in the direction perpendicular to the incident direction of the EM waves, the amplitude ratio and phase difference are linearly dependent on the surface potential. For particulate systems, the surface electric potential and relative refractive index of a charged particle are mathematically expressed by amplitude ratio and phase difference, and a method to estimate the surface potential and the relative refractive index are proposed based on the observation of EM wave signals.

Abstract. The ratio of the receiving power to the transmitting power (RPR) of a well-designed radar system is determined by the absorption and scattering of materials coming into contact with radar waves along the propagating path of the radar wave. In atmospheric detection by a radar system, the RPR is mainly determined by the absorption and scattering of atmospheric particles.Particle properties, such as the charge carried by particles, will affect the RPR. Particle charging is common in a particle system. The present study investigated the effect of charges carried by atmospheric particles on the RPR. It was found that charges carried by 10 particles can increase the RPR, and the increment is related to the charges, particle size, radar emission frequency, and corresponding refractive index of the particles. As the emission frequency of the radar increases, the effect of the charges on the RPR decreases, and especially, the effect of charges on the RPR can be ignored for lidar used to detect sand particles. The number density of particles based on the RPR without considering charges carried by sand particles will be overestimated relative to that when considering charges carried by sand particles. The overestimation increases with the surface charge density, for the same type of radar. 15