ABSTRACT
The morphology of electrochemiluminescence (ECL) emitters is closely related to ECL properties, thus the control of their morphology is greatly essential for ECL applications. Herein, a facile nanoprecipitation method was developed to realize controllable morphology of iridium complex nanomaterials by modulating the volume ratio of poly(styrene-co-maleicanhydride) (PSMA) to tris (2-phenylpyridine) iridium(Ⅲ) (Ir(ppy)3). Furthermore, ECL properties of iridium complex nanomaterials with different morphologies were explored through a series of experiments. Iridium complex nanoparticles (Ir NPs) with excellent ECL performance were selected as admirable ECL emitters to construct biosensors. Ir NPs served as the matrix to stepwise capture primary antibody, antigen of SARS-CoV-2 nucleocapsid protein (ncovNP) and secondary antibody bioconjugate coupled with dual quenchers and detection antibody. Taking advantage of the significant quenching effect of noradrenaline (NA) and gold nanoparticles (Au NPs) in the secondary antibody bioconjugate on ECL emission from Ir NPs, the developed ECL biosensor realized the sensitive detection of ncovNP and the detection limit was as low as 47 fg/mL. The integration of morphology-controlled iridium complex nanomaterials and dual quenchers NA and Au NPs provides a promising ECL platform.
ABSTRACT
The therapeutic effect of tocilizumab remains controversial. We aimed to evaluate whether tocilizumab might be beneficial in COVID-19 patients. We searched PubMed, Embase and Cochrane library from inception to June 23, 2020. Summary estimates of overall response rate (ORR) and all-cause death rate in all patients were analyzed. This study was registered with PROSPERO (CRD42020191313). We included data from 28 articles including 991 COVID-19 patients who underwent tocilizumab administration. The pooled ORR was 72% (95% CI, 66-79%) and pooled all-cause death rate was 16% (95% CI, 11-22%). The optimal timing of administration was the 7.15 day from the symptom onset and with the lowest death rate of 13.11%. 562 patients were defined as with severe infection, and the pooled ORR was 78% (95% CI, 70-85%). The pooled ORR of 56 organ transplantation recipients was 53% (95% CI, 26-78%), which was lower than non-transplant patients [75% (95% CI, 69-81%)]. Nearly all studies confirmed the safety of tocilizumab administration. Tocilizumab improves the clinical outcome of COVID-19 patients, especially in severe cases, and the optimal timing of administration may provide the guidance for management. However, tocilizumab may be used with caution in solid transplant recipients for the suboptimal efficacy.