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Preprint in English | medRxiv | ID: ppmedrxiv-22274949


The SARS-CoV-2 pandemic has profoundly impacted communities across the globe, requiring accurate and accessible diagnostic technologies in support of public health mitigation efforts. As testing has evolved throughout the course of the pandemic, varying sample preparation methodologies have been employed. Herein we perform a comparison of three commercial sample preparation methods: two mechanical homogenization workflows and one enzymatic digestion approach for the detection of SARS-CoV-2 from biomarker genes in 20 human saliva pools. SARS-CoV-2 variants of concern were also identified on the University of Tennessee, Knoxville campus during the spring semester of 2021 utilizing the commercial PerkinElmer PKamp VariantDetect SARS-CoV-2 RT-PCR Assay kit. Two hundred and ten (210) human saliva pools were selected and analyzed for the presence of SARS-CoV-2 variants of concern providing insight into the utility of these various commercial workflows for integration into current public health SARS-CoV-2 surveillance measures.

Journal of Renewable and Sustainable Energy ; 13(2), 2021.
Article in English | Scopus | ID: covidwho-1220093


The COVID-19 pandemic has had a significant negative influence on energy consumption in 2020. On April 7, 2020, in response to the rapid spread of the infection, the Japanese government imposed a state of emergency. This action impacted energy consumption, energy production, and electricity prices. This study compares the impact of a reduction in load demand on renewable energy in the Japan public power grid under a state of emergency declaration (April to May 2020). Using publicly available data, comparisons are made for Kyushu, Tokyo, Kansai, and Hokkaido and assessed in relation to epidemic severity and geographical distribution. The results can be summarized as follows. (1) The consumption profiles and amounts of power consumption reduction are different in different areas. Tokyo shows the largest share of reduced load, followed by Kansai, Kyushu, and Hokkaido. The load reduction was mainly seen during the day, which reflects the differences in people's activities relative to the same period in 2019. (2) Different means of power dispatch, including power generators, energy storage systems, and transmission lines are used and compared in terms of responses to the changes in electricity consumption profile. (3) The overall fall in total load demand and the change in load sequence affected the integration and curtailment of photovoltaic power generation and consequentially caused the electricity price to drop. This paper clarifies the effects of COVID-19 on the public power grids of Japan. Further, it establishes the impact on policymakers in relation to the development of renewable energy. © 2021 Author(s).

Preprint in English | medRxiv | ID: ppmedrxiv-20153106


ObjectivesThe prevalence of antibodies to SARS-CoV-2 among blood donors in China remains unknown. To reveal the missing information, we investigated the seroprevalence of SARS-CoV-2 antibodies among blood donors in the cities of Wuhan, Shenzhen, and Shijiazhuang of China. DesignCross-sectional study SettingThree blood centers, located in the central, south and north China, respectively, recruiting from January to April 2020. Participants38,144 healthy blood donors donated in Wuhan, Shenzhen and Shijiazhuang were enrolled, who were all met the criteria for blood donation during the COVID-19 pandemic in China. Main outcome measuresSpecific antibodies against SARS-CoV-2 including total antibody (TAb), IgG antibody against receptor-binding domain of spike protein (IgG-RBD) and nucleoprotein (IgG-N), and IgM. Pseudotype lentivirus-based neutralization test was performed on all TAb-positive samples. In addition, anonymous personal demographic information, including gender, age, ethnicity, occupation and educational level, and blood type were collected. ResultsA total of 519 samples from 410 donors were confirmed by neutralization tests. The SARS-CoV-2 seroprevalence among blood donors was 2.29% (407/17,794, 95%CI: 2.08% to 2.52%) in Wuhan, 0.029% (2/6,810, 95%CI: 0.0081% to 0.11%) in Shenzhen, and 0.0074% (1/13,540, 95%CI: 0.0013% to 0.042%) in Shijiazhuang, respectively. The earliest emergence of SARS-CoV-2 seropositivity in blood donors was identified on January 20, 2020 in Wuhan. The weekly prevalence of SARS-CoV-2 antibodies in Wuhans blood donors changed dynamically and were 0.08% (95%CI: 0.02% to 0.28%) during January 15 to 22 (before city lockdown), 3.08% (95%CI: 2.67% to 3.55%) during January 23 to April 7 (city quarantine period) and 2.33% (95%CI: 2.06% to 2.63%) during April 8 to 30 (after lockdown easing). Female and older-age were identified to be independent risk factors for SARS-CoV-2 seropositivity among donors in Wuhan. ConclusionsThe prevalence of antibodies to SARS-CoV-2 among blood donors in China was low, even in Wuhan city. According to our data, the earliest emergence of SARS-CoV-2 in Wuhans donors should not earlier than January, 2020. As most of the population of China remained uninfected during the early wave of COVID-19 pandemic, effective public health measures are still certainly required to block viral spread before a vaccine is widely available.