A Gradient pH-Sensitive Polymer-Based Antiviral Strategy via Viroporin-Induced Membrane Acidification.

Lipid-membrane-targeting strategies hold great promise to develop broad-spectrum antivirals. However, it remains a big challenge to identify novel membrane-based targets of viruses and virus-infected cells for development of precision targeted approaches. Here, it is discovered that viroporins, viral-encoded ion channels, which have been reported to mediate release of hydrogen ions, trigger membrane acidification of virus-infected cells. Through development of a fine-scale library of gradient pH-sensitive (GPS) polymeric nanoprobes, the cellular membrane pH transitions are measured from pH 6.8-7.1 (uninfection) to pH 6.5-6.8 (virus-infection). In response to the subtle pH alterations, the GPS polymer with sharp response at pH 6.8 (GPS6.8 ) selectively binds to virus-infected cell membranes or the viral envelope, and even completely disrupts the viral envelope. Accordingly, GPS6.8 treatment exerts suppressive effects on a wide variety of viruses including SARS-CoV-2 through triggering viral-envelope lysis rather than affecting immune pathway or viability of host cells. Murine viral-infection models exhibit that supplementation of GPS6.8 decreases viral titers and ameliorates inflammatory damage. Thus, the gradient pH-sensitive nanotechnology offers a promising strategy for accurate detection of biological pH environments and robust interference with viruses.

Laboratory Diagnosis and Monitoring the Viral Shedding of SARS-CoV-2 Infection.

The worldwide epidemic of coronavirus disease 2019 (COVID-19) is ongoing. Rapid and accurate detection of the causative virus SARS-CoV-2 is vital for the treatment and control of COVID-19. In this study, the comparative sensitivity of different respiratory specimen types were retrospectively analyzed using 3,552 clinical samples from 410 COVID-19 patients confirmed by Guangdong CDC (Center for Disease Control and Prevention). Except for bronchoalveolar lavage fluid (BALF), the sputum possessed the highest positive rate (73.4%-87.5%), followed by nasal swabs (53.1%-85.3%) for both severe and mild cases during the first 14 days after illness onset (d.a.o.). Viral RNA could be detected in all BALF samples collected from the severe group within 14 d.a.o. and lasted up to 46 d.a.o. Moreover, although viral RNA was negative in the upper respiratory samples, it was also positive in BALF samples in most cases from the severe group during treatment. Notably, no viral RNA was detected in BALF samples from the mild group. Despite typical ground-glass opacity observed via computed tomographic scans, no viral RNA was detected in the first three or all upper respiratory tract specimens from some COVID-19 patients. In conclusion, sputum is most sensitive for routine laboratory diagnosis of COVID-19, followed by nasal swabs. Detection of viral RNA in BALF improves diagnostic accuracy in severe COVID-19 patients.

Factors Influencing Public Panic During the COVID-19 Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has been regarded as a public health emergency that caused a considerable degree of public panic (such as anxiety and insomnia) during its early stage. Some irrational behaviors (such as excessive search for information related to the pandemic and excessive hoarding of supplies) were also triggered as a result of such panic. Although there has been plenty of news coverage on public panic due to the outbreak, research on this phenomenon has been limited. Since panic is the main psychological reaction in the early stage of the pandemic, which largely determines the level of psychological adaptation, time of psychological recovery, and the incidence of PTSD, there exists a demand to conduct investigation on it. From a public governance perspective, the government's assessment of public panic may affect the efficiency and effectiveness of pandemic prevention and control. Therefore, it is of obvious practical significance to investigate public panic during the COVID-19 pandemic and analyze its influential factors. The self-compiled COVID-19 Social Mentality Questionnaire was used to collect data from a total of 16,616 participants online, and 13,511 valid responses were received. The results from the chi-square test showed that there were differences in gender, educational level, age, pandemic-related knowledge, self-efficacy, risk level, and objective social support. Furthermore, multiple linear regression analysis results showed that self-efficacy, gender, educational level, age, risk level, pandemic-related knowledge, and objective social support were significant predictors of public panic. Among the research variables, self-efficacy, gender, educational level, and age were negative predictors of panic while risk level, pandemic-related knowledge, and objective social support were positive predictors of panic.

Impact of temperature and relative humidity on the transmission of COVID-19: a modelling study in China and the United States.

OBJECTIVES: We aim to assess the impact of temperature and relative humidity on the transmission of COVID-19 across communities after accounting for community-level factors such as demographics, socioeconomic status and human mobility status. DESIGN: A retrospective cross-sectional regression analysis via the Fama-MacBeth procedure is adopted. SETTING: We use the data for COVID-19 daily symptom-onset cases for 100 Chinese cities and COVID-19 daily confirmed cases for 1005 US counties. PARTICIPANTS: A total of 69 498 cases in China and 740 843 cases in the USA are used for calculating the effective reproductive numbers. PRIMARY OUTCOME MEASURES: Regression analysis of the impact of temperature and relative humidity on the effective reproductive number (R value). RESULTS: Statistically significant negative correlations are found between temperature/relative humidity and the effective reproductive number (R value) in both China and the USA. CONCLUSIONS: Higher temperature and higher relative humidity potentially suppress the transmission of COVID-19. Specifically, an increase in temperature by 1°C is associated with a reduction in the R value of COVID-19 by 0.026 (95% CI (-0.0395 to -0.0125)) in China and by 0.020 (95% CI (-0.0311 to -0.0096)) in the USA; an increase in relative humidity by 1% is associated with a reduction in the R value by 0.0076 (95% CI (-0.0108 to -0.0045)) in China and by 0.0080 (95% CI (-0.0150 to -0.0010)) in the USA. Therefore, the potential impact of temperature/relative humidity on the effective reproductive number alone is not strong enough to stop the pandemic.

Antecedents of Public Mental Health During the COVID-19 Pandemic: Mediation of Pandemic-Related Knowledge and Self-Efficacy and Moderation of Risk Level.

Background: COVID-19 affects not only patients' physical health but also their mental health. For the general public, although their physical health may not be directly affected, their mental health may be affected by stress, anxiety, and social panic caused by COVID-19. Controlling the pandemic should focus on not only physical health but also mental health. For the general public, mental health is even more important, as good mental health at the individual level can form a positive social mentality conducive to pandemic prevention and control. Therefore, it is important to assess mental health during the pandemic, and analyze risk and protective factors. Methods: A self-compiled COVID-19 Social Mentality Questionnaire was used to conduct an online survey. A total of 16,616 participants responded, with 13,511 valid questionnaires. Results: Results showed that 10.7% of participants rated their mental health as "worse than usual" during the pandemic, and there were gender, age, and educational differences. Social support was positively correlated with pandemic-related knowledge and self-efficacy, and could indirectly predict mental health. Pandemic-related knowledge was positively correlated with self-efficacy and mental health, and risk level was negatively correlated with mental health. Hierarchical regression analysis showed that pandemic-related knowledge played a partial mediating role in the relationship between social support and self-efficacy, while self-efficacy played a complete mediating role in the relationship between social support and mental health. Logistic regression analysis showed that risk level moderated the relationship between self-efficacy and mental health. Conclusions: Social support can increase pandemic-related knowledge, thus improving self-efficacy and maintaining/promoting mental health. High risk levels can undermine the role of self-efficacy in promoting mental health. Therefore, in the fight against the COVID-19, people need to support and cooperate with each other, to improve self-efficacy and reduce risk, thus maintaining and promoting mental health.