Plasma cell-free DNA promise disease monitoring and tissue injury assessment of COVID-19 (preprint)

COVID-19 is a huge threat to global health. Due to the lack of definitive etiological therapeutics currently, effective disease monitoring is of high clinical value for better healthcare and management of the large number of COVID-19 patients. In this study, we recruited 37 COVID-19 patients, collected 176 blood samples upon diagnosis and during treatment, and analyzed cell-free DNA (cfDNA) in these samples. We report gross abnormalities in cfDNA of COVID-19 patients, including elevated GC content, altered molecule size and end motif patterns. More importantly, such cfDNA characteristics reflect patient-specific physiological conditions during treatment. Further analysis on tissue origin tracing of cfDNA reveals frequent tissue injuries in COVID-19 patients, which is supported by clinical diagnoses. Hence, we demonstrate the translational merit of cfDNA as valuable analyte for effective disease monitoring, as well as tissue injury assessment in COVID-19 patients.

Efficiency of China’s carbon market: A case study of Hubei pilot market

Better understanding the carbon market can instruct further reforms to perfect its functionality, market efficiency is a key indicator to uncover its current performance. Previous studies have revealed foregone carbon market efficiency;however, given the dynamics of market, it merits the significance to track the up-to-date status. This paper specifically studies the Hubei pilot carbon market, which is quite representative considering its market scale as well as the COVID-19 pandemic context. Wild bootstrapping Variance Ratio test is implemented to detect the market efficiency with the most recent and abundant data. Results show that the market efficiency in the period of 2014 to 2020 is around 0.3951, less than 1, suggesting the weak form efficiency. Observing from sub-sample periods, the efficiency volatiles: climbed from 0.3621 to 0.4027, but drop to 0.3985 finally. Furthermore, the market efficiency soaring after the COVID-19, which echoes the smooth reopening and local supporting policies. To some extent, this study enlarged the impact study of COVID-19, which should be meaningful for further research. Unique contribution of this paper is providing latest evidence for the efficiency of China’s pilot carbon market, as well as proofs for soaring market efficiency after the pandemic.

Thymosin alpha-1 Protected T Cells from Excessive Activation in Severe COVID-19 (preprint)

Two typical features of uncontrolled inflammation, cytokine storm and lymphopenia, are associated with the severity of coronavirus disease 2019 (COVID-19), demonstrating that both innate and adaptive immune responses are involved in the development of this disease. Recent studies have explored the contribution of innate immune cells to the pathogenesis of the infection. However, the impact of adaptive immunity on this disease remains unknown. In order to clarify the role of adaptive immune response in COVID-19, we characterized the phenotypes of lymphocytes in PBMCs from patients at different disease stages using single-cell RNA sequencing (scRNA-seq) technology. Dynamics of the effector cell levels in lymphocytes revealed a distinct feature of adaptive immunity in severely affected patients, the coincidence of impaired cellular and enhanced humoral immune responses, suggesting that dysregulated adaptive immune responses advanced severe COVID-19. Excessive activation and exhaustion were observed in CD8 T effector cells, which might contribute to the lymphopenia. Interestingly, expression of Prothymosin alpha (PTMA), the proprotein of Tα1, was significantly increased in a group of CD8 T memory stem cells, but not in excessively activated T cells. We further showed that Tα1 significantly promoted the proliferation of activated T cells in vitro and relieved the lymphopenia in COVID-19 patients. Our data suggest that protection of T cells from excessive activation might be critical for the prevention of severe COVID-19.