Assessing SARS-CoV-2 RNA levels and lymphocyte/T cell counts in COVID-19 patients revealed initial immune status as a major determinant of disease severity.

The magnitude of SARS-CoV-2 infection, the dynamic changes of immune parameters in patients with the novel coronavirus disease (COVID-19) and their correlation with the disease severity remain unclear. The clinical and laboratory results from 154 confirmed COVID-19 patients were collected. The SARS-CoV-2 RNA levels in patients were estimated using the Ct values of specific RT-PCR tests. The lymphocyte subsets and cytokine profiles in the peripheral blood were analyzed by flow cytometry and specific immunoassays. 154 confirmed COVID-19 patients were clinically examined up to 4 weeks after admission. The initial SARS-CoV-2 RNA Ct values at admission varied, but were comparable in the patient groups classified according to the age, gender, underlying diseases, and disease severity. Three days after admission, significant higher Ct values were found in severe cases. Significantly reduced counts of T cells and T cell subsets were found in patients with old age and underlying diseases at admission and were characteristic for the development of severe COVID-19. Severe COVID-19 developed preferentially in patients with underlying compromised immunity and was not associated with initial virus levels. Higher SARS-CoV-2 RNA levels in severe cases were apparently a result of impaired immune control associated with dysregulation of inflammation.

[Effect of Fe2+ on fermentation hydrogen production in an UASB].

Fe2+ has an important effect on the production of hydrogen in a biological way. With the brown sugar as the substrate, the effect of biotechnology hydrogen production capacity of the Fe2+ concentration ranging from 0-1650 mg x L(-1) on the condition of anaerobic fermentation was studied. The results showed that appropriate divalent ions had the ability to enhance the hydrogen production. Biogas amounts and hydrogen content increased with increasing Fe2+ concentration from 0-450 mg x L(-1). Compared with the control group increased by 40.75%, the maximum biogas amount of 17.72 L was obtained at Fe2+ concentration of 450 mg x L(-1). And at the same time, the hydrogen content was 60.01 percent. Biogas amounts and hydrogen content decreased gradually when the concentration of Fe2+ was higher than 450 mg x L(-1). Therefore Fe2+ is one of important engineering parameters for the fermentative hydrogen production.