Genome charaterization based on the Spike-614 and NS8-84 loci of SARS-CoV-2 reveals two major onsets of the COVID-19 pandemic (preprint)

The global COVID-19 pandemic has lasted for three years since its outbreak, however its origin is still unknown. Here, we analyzed the genotypes of 3.14 million SARS-CoV-2 genomes based on the amino acid 614 of the Spke (S) and the amino acid 48 of NS8 (nonstructural protein 8), and identified 16 linkage haplotypes. The GL haplotype (S_614G and NS8_48L) was the major haplotype driving the global pandemic and accounted for 99.2% of the sequenced genomes, while the DL haplotype (S_614D and NS8_48L) caused the pandemic in China in the spring of 2020 and accounted for approximately 60% of the genomes in China and 0.45% of the global genomes. The GS (S_614G and NS8_48S), DS (S_614D and NS8_48S) and NS (S_614N and NS8_48S) haplotypes accounted for 0.26%, 0.06%, and 0.0067% of the genomes, respectively. The main evolutionary trajectory of SARS-CoV-2 is DS[->]DL[->]GL, whereas the other haplotypes are minor byproducts in the evolution. Surprisingly, the newest haplotype GL had the oldest time of most recent common ancestor (tMRCA), which was May 1 2019 by mean, while the oldest haplotype had the newest tMRCA with a mean of October 17, indicating that the ancestral strains that gave birth to GL had been extinct and replaced by the more adapted newcomer at the place of its origin, just like the sequential rise and fall of the delta and omicron variants. However, they arrived and evolved into toxic strains and ignited a pandemic in China where the GL strains did not exist at the end of 2019. The GL strains had spread all over the world before they were discovered, and ignited the global pandemic, which had not been noticed until the pandemic was declared in China. However, the GL haplotype had little influence in China during the early phase of the pandemic due to its late arrival as well as the strict transmission controls in China. Therefore, we propose two major onsets of the COVID-19 pandemic, one was mainly driven by the haplotype DL in China, the other was driven by the haplotype GL globally.

Prediction of Wall and Indoor Hygrothermal Properties of Rammed Earth Folk House in Northwest Sichuan

The climate crisis is one of the most important problems today. In the process of human building, the use of cement, steel, and other industrial materials in the process of building construction and recycling has brought a huge burden to the natural environment. Earth is one of the oldest building materials, its availability and insulation make it an excellent constructive solution in human history. Among several existing earth construction techniques, rammed earth is one of the most relevant. In this paper, a numerical model of the rammed earth folk house in Mianyang was established, and an experimental device was built to verify it. With the typical meteorological year data of Mianyang in northwest Sichuan, the heat and moisture transfer in rammed earth wall, as well as the indoor thermal and moisture environment were numerically simulated. The results show that the rammed earth wall weakens the temperature fluctuation of the inner surface of the wall and makes the peak temperature of the inner surface of the wall lag the outer surface. The relative humidity in the center of the rammed earth wall can be maintained at about 60%, both in winter and summer. The moisture absorption and desorption capacity of rammed earth walls without inner decorative materials is about three times that of gypsum board, and the use of a waterproof coating will render the rammed earth wall almost unable to adjust the indoor relative humidity. Additionally, the use of decorative materials will increase the fluctuation range of indoor relative humidity and the risk of mold breeding.

Construction of a Home Exercise Prescription Solution for Youth During a Serious Public Health Emergency in China (preprint)

BackgroundCoronavirus disease 2019 (COVID-19) was identified as a serious public health emergency. The Chinese government required people to stay at home. The purpose of this study was to analyse the effect of home exercise prescription solutions on the physical and mental health of youth during the COVID-19 period.MethodsA home exercise prescription was formulated after investigating and categorizing the home exercise status of 4000 undergraduates during the period of COVID-19. In this prospective cohort study, 200 young people were recruited for a home exercise prescription intervention, and 200 individuals did not undergo any intervention for 4 weeks in February 2020. Physical and mental health indexes including anxiety factors, obsessive-compulsive symptoms factors, depression factors, somatization subscale factors, and sleep and diet factors were evaluated.ResultsOf 4,000 undergraduates living at home, 64.8% were dissatisfied with their physical and mental condition. Ninety-three percent wanted to adopt an exercise practice at home during the period of COVID-19. In the prospective cohort study, the average anxiety scores and sleep and diet scores before the intervention were 2.14 ± 0.43 and 2.24 ± 0.54, respectively, in the intervention group. After 4 weeks, participants reported that negative emotions were reduced. The scores for all factors were less than 2 points, and there were significant differences between the pre-intervention and post-intervention time points (P < 0.05). Differences between the two groups were statistically significant at 2 and 4 weeks (P < 0.05).ConclusionThere was an urgent need for home exercise programmes for youth during the period of COVID-19. Formulating appropriate home exercise prescriptions could help maintain physical and mental health, enhance immunity, and prevent disease.Trial registration  ChiCTR, ChiCTR2000030090, Registered February 24th, 2020. http://www.chictr.org.cn/edit.aspx 

Restoration of leukomonocyte counts is associated with viral clearance in COVID-19 hospitalized patients (preprint)

Background: Viral clearance is one important indicator for the recovery of SARS-CoV-2 infected patients. Suboptimal T and B cell responses can delay viral clearance in MERS and SARS patients. The role of leukomonocytes in viral clearance of COVID-19 patients is not yet well defined.Methods: From January 26 to February 28, 2020, an observational study was launched at Zhongnan Hospital of Wuhan University, Wuhan, China. We enrolled 25 laboratory-confirmed COVID-19 patients, whose throat-swab specimens were tested positive for SARS-CoV-2 infection by qRT-PCR. We comprehensively analyzed clinical records, counts of lymphocyte subsets including CD3+, CD4+, CD8+ T cells, B cells and NK cells in the patients who successfully cleared SARS-CoV-2, and compared to those that failed to, after a standardized treatment of 8-14 days. Findings: In 25 enrolled COVID-19 patients, lymphopeniawas a common feature. After the treatment, 14 patients were tested negative for SARS-CoV-2. The patients that cleared the infection had restored the numbers of CD3+, CD4+, CD8+ T cellsand B cells as compared to the still viral RNA positive patients, while the recovered patients had a higher count of leukomonocytes. Conclusions: By comparison of leukomonocytes counts in COVID-19 patients at different stages of the disease, we found that CD3+, CD4+, CD8+ T cells and B cells appear to play important roles in viral clearance. The restoration of leukomonocytes counts from peripheral blood can be used as prognosis for the recovery of an COVID-19 infection. We propose that restoration of leukomonocytes counts can be added to the COVID-19 diagnostic guidanceas a criterion for releasing and discharging patients.