ABSTRACT
Surface longwave downward radiation (LWDR) is a key factor affecting the surface energy balance. The daily LWDR and the diurnal variations of LWDR are of great significance for studies of climate change and surface processes. How to obtain LWDR at an averaged temporal scale from instantaneous LWDR is one of the longstanding problems in the field of radiation budget from remote sensing. In this paper, two temporal upscaling methods are introduced, namely, a method based on the diurnal variations of LWDR (diurnal variation based, DVB) and a method based on random forest regression (RFR). The results reveal that: (1) The DVB method has a global hourly and daily LWDR root-mean-square error (RMSE) of less than 21 W/m2 and 15 W/m2, respectively, and the RMSE of the daily LWDR based on RFR is less than 7 W/m2;(2) When compared with four existing statistical interpolation methods, the DVB method can not only ensure the accuracy, but also can overcome the problem of missing samples and/or an abnormal samples during upscaling;(3) Except for directly predict daily LWDR, the DVB methods can also obtain more accurate LWDR diurnal variations such as hourly, half-hourly etc. The RFR method enables high-efficiency and accurate estimation of daily averaged LWDR from instantaneous measurements. Compared with existing methods and products, the proposed methods are not only efficient, but also have a superior applicability and reliable accuracy. The proposed strategies provide new ideas for the community in estimating LWDR at continuous temporal scales from remotely sensed measurements.
ABSTRACT
The global pandemic of the COVID-19 has had a major impact on the entire human society, and human beings are facing challenges such as fiscal stimulus, financial stress, and debt restructuring. Before the emergence of specific therapeutic drugs and methods, large-scale population screening and isolation has become the most effective method for epidemic management. However, the new strain of coronavirus this time has shown a very high genetic variability, with a statistical mutation rate of more than 2. 3%c as of March 31st, 2022. So far, new highly infectious virus strains have been emerging, and the number of mutant strains officially warned by the World Health Organization has reached 7. Therefore, in the next virus prevention and control and research, we not only need to detect SARS-CoV-2, but also need to explore accurate and practical single nucleotide variation (SNV) genotyping techniques, especially for large-scale population screening. It is not only necessary to obtain information on the SRAS-CoV-2, but also to accurately and quickly distinguish variant strains with higher infectivity and virulence. This paper briefly introduces the infection and mutation mechanism of the virus, and focuses on the classification and review of the existing main SARS-CoV-2 SNV genotyping techniques, hoping to provide insight into the development of new detection technolooies. © 2022, China Biotechnology Press. All rights reserved.
ABSTRACT
The outbreak of coronavirus disease-19 (COVID-19) caused by novel coronavirus (severe acute respiratory syndrome coronavirus-2, SARS-CoV-2) has posed a serious threat to public health. Virus particles of SARS-CoV-2 are composed of outer envelopes and inner nucleocapsids. The nonstructural and structural proteins encoded by the genome play an important role in the whole life cycle of their adsorption, penetration, uncoating, synthesis of nucleic acids and proteins, assembly and liberation. Antiviral drugs can be developed to target the virus itself or key host molecules for virus infection. So far, antibody drugs targeting spike glycoprotein S and small molecule drugs targeting RNA polymerase have shown antiviral effects. They are currently more promising candidate drugs. However, their efficacy still needs to be proved by further clinical trials, and miracle antiviral drugs have not yet appeared. Considering the virus and host targets, the combination therapy of multi-targets and multidrugs, may achieve better therapeutic effect. In this paper, the structure and life cycle of SARS-CoV-2, the research progress in potential targets and drugs were reviewed to provide useful information for the development of anti-SARS-CoV-2 drugs.