M-targeted anti-SARS-CoV-2 inhibitor-based drugs.

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 is a global health emergency. The main protease is an important drug target in coronaviruses. It plays an important role in the processing of viral RNA-translated polyproteins and is highly conserved in the amino acid sequence and three-dimensional structure, making it a good drug target for which several small molecule inhibitors are available.

Robust Nitritation of Anaerobic Digester Centrate Using Dual Stressors and Timed Alkali Additions.

Nitrogen is commonly removed from wastewater by nitrification to nitrate followed by nitrate reduction to N. Shortcut N removal saves energy by limiting ammonia oxidation to nitrite, but nitrite accumulation can be unstable. We hypothesized that repeated short-term exposures of ammonia-oxidizing communities to free ammonia (FA) and free nitrous acid (FNA) would stabilize nitritation by selecting against nitrite-oxidizing bacteria (NOB).

Nitrogen removal as nitrous oxide for energy recovery: Increased process stability and high nitrous yields at short hydraulic residence times.

The Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) is a two-stage process for nitrogen removal and resource recovery: in the first, ammonia is oxidized to nitrite in an aerobic bioreactor; in the second, oxidation of polyhydroxyalkanoate (PHA) drives reduction of nitrite to nitrous oxide (NO) which is stripped for use as a biogas oxidant. Because ammonia oxidation is well-studied, tests of CANDO to date have focused on NO production in anaerobic/anoxic sequencing batch reactors. In these reactors, nitrogen is provided as nitrite; PHA is produced from acetate or other dissolved COD, and PHA oxidation is coupled to NO production from nitrite.

Bio-entrapped membrane reactor and salt marsh sediment membrane bioreactor for the treatment of pharmaceutical wastewater: treatment performance and microbial communities.

In this study, a bio-entrapped membrane reactor (BEMR) and a salt marsh sediment membrane bioreactor (SMSMBR) were evaluated to study the organic treatment performance of pharmaceutical wastewater. The influences of hydraulic retention time (HRT) and salinity were also studied. The conventional biomass in the BEMR cannot tolerate well of the hypersaline conditions, resulting in total chemical oxygen demand (TCOD) removal efficiency of 54.