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The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic of novel corona virus disease (COVID-19). The neutralizing monoclonal antibodies (mAbs) targeting the receptor binding domain (RBD) of SARS-CoV-2 are among the most promising strategies to prevent and treat COVID-19. However, SARS-CoV-2 variants of concern (VOCs) profoundly reduced the efficacies of most of mAbs and vaccines approved for clinical use. Herein, we demonstrated mAb 35B5 efficiently neutralizes both wild-type (WT) SARS-CoV-2 and VOCs, including B.1.617.2 (delta) variant, in vitro and in vivo. Cryo-electron microscopy (cryo-EM) revealed that 35B5 neutralizes SARS-CoV-2 by targeting a unique epitope that avoids the prevailing mutation sites on RBD identified in circulating VOCs, providing the molecular basis for its pan-neutralizing efficacy. The 35B5-binding epitope could also be exploited for the rational design of a universal SARS-CoV-2 vaccine.
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Objective To invesitgate the relationship between 8-iseprostane (8-iso-PG) level in exhaled breath condensates (EBCs) and severity of asthma and explore the role of 8-iso-PG in asthma evaluation and monitoring.Methods Fifty-nine patients with asthma were enrolled.In which 15 eases were acute exacerbation, 13 eases were mild intermittent, 15 eases were mild persistent, and 16 eases were mederate-to-severe persistent.Thirteen healthy volunteers were recruited as control.EBCs were collected using EeoSereen system.The 8-iso-PG levels in EBCs were measured by a specific enzyme immunoassay.The patients with mild intermittent asthma were treated with inhaled corticosteroid (ICS) for one month and their EBCs were recollected for 8-iso-PG measurement.Results Exhaled 8-iso-PG levels were obviously increased in the patients with acute asthma compared with those chronic asthmatics [(47.2±6.8) pg/mL vs (24.5±12.0) pg/mL, P < 0.01].In the chronic persistent asthma, the levels were significantly higher in patients with mild persistent and moderate-to-severe asthma [(17.9±1.2) pg/mL and (39.7±4.0) pg/mL, P <0.01].While 8-iso-PG level did not differ significantly in intermittent asthma [(13.5±1.1) pg/mL] compared with the control subjects (P > 0.05).After one-month ICS treatment the 8-iso-PG level in the patients with mild intermittent asthma did not change significantly although the ACT score improved.Conclusions 8-iso-PG levels in EBC are associated with the severity of asthma,implicating 8-iso-PG may be useful in monitoring airway oxidative stress in asthma.ICS treatment is incapable of decreasing the 8-iso-PG,suggesting the ICS has minor impact on oxidative stress.
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The zinc finger transcription factor Egr-1 is critical for coupling extracellular signals to changes in cellular gene expression. In the hippocampus and amygdala, two major central regions for memory formation and storage, Egr-1 is up-regulated by long-term potentiation (LTP) and learning paradigms. Using Egr-1 knockout mice, we showed that Egr-1 was selectively required for late auditory fear memory while short term, trace and contextual memory were not affected. Additionally, synaptic potentiation induced by theta burst stimulation in the amygdala and auditory cortex was significantly reduced or blocked in Egr-1 knockout mice. Our study suggests that the transcription factor Egr-1 plays a selective role in late auditory fear memory.
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In the present work, we developed a new kind of electrorheological (ER) materials, metal cations modified amorphous TiO(2) gels. The static yield stress of Sn(4+) modified amorphous TiO(2) gel based ER fluid with a volume fraction Phi = 38% reaches 26.2 kPa at E = 3.5 kV/mm. The result shows that metal cations can significantly enhance the ER activity of amorphous TiO(2) gels. We then proposed a novel ER effect mechanism (metal cations enhanced polarization mechanism) to clarify the experimental results. We believe that it is the metal cations that enhanced the polarization of the polar groups (-OH) which results in the corresponding enhancement of the interfacial polarization.
