C5 peptide

The novel coronavirus disease COVID-19 originates in the lungs, but it may extend to other organs, causing, in severe cases, multiorgan damage, including cardiac injury and acute kidney injury. In severe cases, the presence of kidney injury is associated with increased risk of death, highlighting the relevance of this organ as a target of SARS-CoV-2 infection. COVID-19-associated tissue injury is not primarily mediated by viral infection, but rather is a result of the inflammatory host immune response, which drives hypercytokinemia and aggressive inflammation that affect lung parenchymal cells, diminishing oxygen uptake, but also endothelial cells, resulting in endotheliitis and thrombotic events and intravascular coagulation. The complement system represents the first response of the host immune system to SARS-CoV-2 infection, but there is growing evidence that unrestrained activation of complement induced by the virus in the lungs and other organs plays a major role in acute and chronic inflammation, endothelial cell dysfunction, thrombus formation, and intravascular coagulation, and ultimately contributes to multiple organ failure and death. In this review, we discuss the relative role of the different complement activation products in the pathogenesis of COVID-19-associated tissue inflammation and thrombosis and propose the hypothesis that blockade of the terminal complement pathway may represent a potential therapeutic option for the prevention and treatment of lung and multiorgan damage.

The optimization of cobalt oxide (Co3O4) loading on silica for the low-temperature Fischer-Tropsch (LTFT) synthesis process employing simulated nitrogen-rich syngas (50 vol%) to produce highly paraffinic biodiesel is studied. Four different amounts of Co3O4 varying from 15 to 36 wt% were loaded on silica in order to examine the catalytic performance of Co/SiO2 catalysts. The supported catalysts were characterized using XRF, nitrogen physisorption, XRD, TPR, DRIFT and SEM fixed with EDS analysis. The performances of the catalysts were examined in a single channel fixed bed reactor employing simulated nitrogen-rich syngas (CO:H-2:N-2 = 17:33:50 vol%). The reactor was operated at P = 20 bar, T = 237 degrees C and WHSV = 3.0 Nl/h.g(cat). The active site concentration was maximized by (i) utilizing all the available surface area of the sphere's porous support, (ii) using ethanolic impregnation solution to hinder sintering of Co3O4 phases due to presence of ethoxyl groups, and (iii) connecting oxide crystallites to the neighbouring pores by increasing the active metal content. As a result, the production of heavy hydrocarbons per unit of time was maximized with 36 wt% cobalt loading on silica (CO conversion and C5+ selectivity were 87.65 and 81.78 mol%, respectively, and also paraffin: olefin ratio was 98:2).