The coronavirus disease pandemic of 2019 caused by the novel SARS-CoV-2 coronavirus resulted in economic losses and threatened human health worldwide. The pandemic highlights an urgent need for a stable, easily produced, and effective vaccine. SARS-CoV-2 uses the spike protein receptorbinding domain (RBD) to bind its cognate receptor, angiotensinconverting enzyme 2 (ACE2), and initiate membrane fusion. Thus, the RBD is an ideal target for vaccine development. In this study, we designed three different RBD-conjugated nanoparticle vaccine candidates, namely, RBD-Ferritin (24-mer), RBD-mi3 (60-mer), and RBD-I53−50 (120-mer), via covalent conjugation using the SpyTag-SpyCatcher system. When mice were immunized with the RBD-conjugated nanoparticles (NPs) in conjunction with the AddaVax or Sigma Adjuvant System, the resulting antisera exhibited 8-to 120-fold greater neutralizing activity against both a pseudovirus and the authentic virus than those of mice immunized with monomeric RBD. Most importantly, sera from mice immunized with RBD-conjugated NPs more efficiently blocked the binding of RBD to ACE2 in vitro, further corroborating the promising immunization effect. Additionally, the vaccine has distinct advantages in terms of a relatively simple scale-up and flexible assembly. These results illustrate that the SARS-CoV-2 RBD-conjugated nanoparticles developed in this study are a competitive vaccine candidate and that the carrier nanoparticles could be adopted as a universal platform for a future vaccine development.

This paper studied the ultrasonic removal of indigenous blue-green algae taken from Lake Taihu. The results showed that higher ultrasound frequency benefited the removal of indigenous algae. But in consideration of complex condition of the natural lakes and reservoirs such as the lack of powerful electrical supply system, low sound frequency is more suitable. Because of slightly improvement in the algae removal rate constants among the low frequency range (20-100 kHz), 20 kHz is the best ultrasound frequency for indigenous algae removal. Moreover, little change in the microcystins concentration was found with sonication at 20 kHz, 2W for 60s, which was compared with the increased microcystins from 2.67 to 2.851 mg/L after sonication at 1000 kHz, 2W for 60s. the concentration of chlorophyll.

No abstract

Yeast SP1 was selected from the three strains to remove chemical oxygen demand (COD) in wastewater from refining part of N, 2, 3-trimethyl-2-isopropyl butanamide (WS-23). The effects of some factors on the degradation for wastewater from refining part of WS-23 were investigated and the optimum conditions for biological water treatment by yeast SP1 were obtained through orthogonal experiments. The results indicate that this wastewater can be treated directly by yeast without any pre-treatment and the best conditions are as follows: inoculum is 10% (v/v), reaction temperature at 30 °C for 48 h. Under these conditions, the total COD removal efficiency can reach 87.11%. In addition, according to Monod model, the kinetics parameters were obtained from the experiments by determining influent COD (S0), effluent COD (Se), biomass (X) and the kinetics of COD removal was established, furthermore, the difference of experimental and calculated values was within 1 hour by testing.