PdPtRu trimetallic nanozymes and application to electrochemical immunosensor for sensitive SARS-COV-2 antigen detection.

Herein, a ternary PdPtRu nanodendrite as novel trimetallic nanozyme was reported, which possessed excellent peroxidase-like activity as well as electro-catalytic activity on account of the synergistic effect between the three metals. Based on the excellent electro-catalytic activity of trimetallic PdPtRu nanozyme toward the reduction of H2O2, the trimetallic nanozyme was applied to construct a brief electrochemical immunosensor for SARS-COV-2 antigen detection. Concretely, trimetallic PdPtRu nanodendrite was used to modify electrode surface, which not only generated high reduction current of H2O2 for signal amplification, but also provided massive active sites for capture antibody (Ab1) immobilization to construct immunosensor. In the presence of target SARS-COV-2 antigen, SiO2 nanosphere labeled detection antibody (Ab2) composites were introduced on the electrode surface according sandwich immuno-reaction. Due to the inhibitory effect of SiO2 nanosphere on the current signal, the current signal was decreased with the increasing target SARS-COV-2 antigen concentration. As a result, the proposed electrochemical immunosensor presented sensitive detection of SARS-COV-2 antigen with linear range from 1.0 pg/mL to 1.0 µg/mL and limit of detection down to 51.74 fg/mL. The proposed immunosensor provide a brief but sensitive antigen detection tool for rapid diagnosis of COVID-19.

The effectiveness of nonfinancial interventions and monetary incentives on COVID-19 vaccination: A meta-analysis.

OBJECTIVE: Although mass vaccination is critical for curbing the spread of COVID-19 and saving lives, vaccine rates remain suboptimal in most countries, calling for effective behavioral interventions to promote vaccinations. Nonfinancial behavioral interventions and monetary incentives are commonly used to promote COVID-19 vaccination but their effects are mixed. METHOD: Articles were searched in the Web of Science, PubMed, and PsycINFO databases. Previous review papers, Google Scholar search, references from the included articles, and unpublished databases were also searched for any other relevant articles. RESULTS: Drawing on 71 studies comprising 1,132,533 participants and 233 effect sizes, we found that the overall behavioral interventions (including nonfinancial interventions and monetary incentives) have a small but statistically significant effect size of Cohen's d = 0.20, 95% confidence interval [0.08, 0.31]. Different types of single interventions and combined strategies produce similar effects. Effect sizes were not moderated by early/late implementation time points, except that collective benefit-oriented interventions showed a marginally significant downward trend as COVID-19 evolves. The effect size of nonfinancial interventions did not significantly differ from monetary incentives. CONCLUSIONS: Our findings affirm the value of nonfinancial strategies and may help forecast the effectiveness of future interventions for ever-evolving pandemics. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Highly sensitive electrochemical aptasensor for SARS-CoV-2 antigen detection based on aptamer-binding induced multiple hairpin assembly signal amplification.

In this work, a brief electrochemical aptasensor was developed for highly sensitive detection of SARS-CoV-2 antigen utilizing an aptamer-binding induced multiple hairpin assembly strategy for signal amplification. In the presence of SARS-CoV-2, a pair of aptamers was brought in a close proximity according to the aptamer-protein antigen binding, which initiated strand displacement reaction thereby triggering a multiple hairpin assembly to obtain long linear DNA concatemers on the electrode surface. As the fabricated hairpin probes were labeled with biotin, massive streptavidin-alkaline phosphatases (ST-ALP) could be further introduced on the electrode interface via biotin-streptavidin interaction thus generating strong electrochemical signal in electrolyte solution containing 1-naphthol phosphate. Benefiting from the non-enzymatic multiple hairpin assembly signal amplification strategy, the designed aptasensor for SARS-CoV-2 spike protein detection exhibited the wide linear range from 50 fg·mL-1 to 50 ng·mL-1 and low detection limit of 9.79 fg·mL-1. Meaningfully, this proposed electrochemical assay provided a potential application for the point of care analysis of viral diseases under ambient temperature.

The functional connectome predicts feeling of stress on regular days and during the COVID-19 pandemic.

Although many studies have explored the neural mechanism of the feeling of stress, to date, no effort has been made to establish a model capable of predicting the feeling of stress at the individual level using the resting-state functional connectome. Although individuals may be confronted with multidimensional stressors during the coronavirus disease 2019 (COVID-19) pandemic, their appraisal of the impact and severity of these events might vary. In this study, connectome-based predictive modeling (CPM) with leave-one-out cross-validation was conducted to predict individual perceived stress (PS) from whole-brain functional connectivity data from 817 participants. The results showed that the feeling of stress could be predicted by the interaction between the default model network and salience network, which are involved in emotion regulation and salience attribution, respectively. Key nodes that contributed to the prediction model comprised regions mainly located in the limbic systems and temporal lobe. Critically, the CPM model of PS based on regular days can be generalized to predict individual PS levels during the COVID-19 pandemic, which is a multidimensional, uncontrollable stressful situation. The stability of the results was demonstrated by two independent datasets. The present work not only expands existing knowledge regarding the neural mechanism of PS but also may help identify high-risk individuals in healthy populations.