The CRISPR/Cas System: A Customizable Toolbox for Molecular Detection.

Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins (Cas) are promising molecular diagnostic tools for rapidly and precisely elucidating the structure and function of genomes due to their high specificity, programmability, and multi-system compatibility in nucleic acid recognition. Multiple parameters limit the ability of a CRISPR/Cas system to detect DNA or RNA. Consequently, it must be used in conjunction with other nucleic acid amplification techniques or signal detection techniques, and the reaction components and reaction conditions should be modified and optimized to maximize the detection performance of the CRISPR/Cas system against various targets. As the field continues to develop, CRISPR/Cas systems have the potential to become an ultra-sensitive, convenient, and accurate biosensing platform for the detection of specific target sequences. The design of a molecular detection platform employing the CRISPR/Cas system is asserted on three primary strategies: (1) Performance optimization of the CRISPR/Cas system; (2) enhancement of the detection signal and its interpretation; and (3) compatibility with multiple reaction systems. This article focuses on the molecular characteristics and application value of the CRISPR/Cas system and reviews recent research progress and development direction from the perspectives of principle, performance, and method development challenges to provide a theoretical foundation for the development and application of the CRISPR/CAS system in molecular detection technology.

Social isolation, psychological distress and resilience of Chinese college students during COVID-19 pandemic.

It has been 3 years since the first appearance of COVID-19 in China. During this time, social isolation was widely used as an important method to fight it. However, this measure had many negative effects on the mental health of college students. To better understand this issue, this study aims to explore the impact of social isolation and COVID-19-related stress on psychological distress among Chinese college students. Additionally, resilience has been evaluated as a key component of stress resistance in this situation. Coronavirus Stress Measure (CSM), the Connor-Davidson Resilience Scale (CD-RISC) and the Brief Symptom Inventory (BSI) were used in this study. A total of 388 Chinese college students participated in the survey via the Internet. Two groups (isolated group vs. non-isolated group) were divided according to whether they have been isolated from their classmates and families. Data analysis adopts t-test, F test and mediate effect analysis by SPSS21.0. (1) All factors, except resilience, were found to have lower scores in the isolated group; (2) significant correlations were found between all factors; (3) resilience partially mitigated the impact of COVID-19 stress on psychological symptoms. Social isolation has been found to be a significant factor contributing to negative psychological distress in Chinese college students. The COVID-19-related stress may increase the likelihood of psychological suffering among isolated group. Resilience can help reduce the negative effects of COVID-19 stress on college students. Therefore, providing appropriate psychological support tailored to different isolation situations is crucial.

A Phase 1, Randomized, Double-Blinded, Placebo-Controlled and Dose-Escalation Study to Evaluate the Safety and Immunogenicity of the Intranasal DelNS1-nCoV-RBD LAIV for COVID-19 in Healthy Adults.

An intranasal COVID-19 vaccine, DelNS1-based RBD vaccines composed of H1N1 subtype (DelNS1-nCoV-RBD LAIV) was developed to evaluate the safety and immunogenicity in healthy adults. We conducted a phase 1 randomized, double-blinded, placebo-controlled study on healthy participants, age 18-55 and COVID-19 vaccines naïve, between March and September 2021. Participants were enrolled and randomly assigned (2:2:1) into the low and high dose DelNS1-nCoV-RBD LAIV manufactured in chicken embryonated eggs or placebo groups. The low and high-dose vaccine were composed of 1 × 107 EID50/ dose and 1 × 107.7 EID50/ dose in 0.2 mL respectively. The placebo vaccine was composed of inert excipients/dose in 0.2 mL. Recruited participants were administered the vaccine intranasally on day 0 and day 28. The primary end-point was the safety of the vaccine. The secondary endpoints included cellular, humoral, and mucosal immune responses post-vaccination at pre-specified time-points. The cellular response was measured by the T-cell ELISpot assay. The humoral response was measured by the serum anti-RBD IgG and live-virus neutralizing antibody against SARS-CoV-2. The saliva total Ig antibody responses in mucosal secretion against SARS-CoV-2 RBD was also assessed. Twenty-nine healthy Chinese participants were vaccinated (low-dose: 11; high-dose: 12 and placebo: 6). The median age was 26 years. Twenty participants (69%) were male. No participant was discontinued due to an adverse event or COVID-19 infection during the clinical trial. There was no significant difference in the incidence of adverse events (p = 0.620). For the T-cell response elicited after full vaccination, the positive PBMC in the high-dose group increased to 12.5 SFU/106 PMBC (day 42) from 0 (baseline), while it increased to 5 SFU/106 PBMC (day 42) from 2.5 SFU/106 PBMC (baseline) in the placebo group. The high-dose group showed a slightly higher level of mucosal Ig than the control group after receiving two doses of the vaccine (day 31, 0.24 vs. 0.21, p = 0.046; day 56 0.31 vs. 0.15, p = 0.45). There was no difference in the T-cell and saliva Ig response between the low-dose and placebo groups. The serum anti-RBD IgG and live virus neutralizing antibody against SARS-CoV-2 were undetectable in all samples. The high-dose intranasal DelNS1-nCoV-RBD LAIV is safe with moderate mucosal immunogenicity. A phase-2 booster trial with a two-dose regimen of the high-dose intranasal DelNS1-nCoV-RBD LAIV is warranted.

Dynamic observation and qualitative analysis of a psychological crisis hotline during the COVID-19 pandemic

Objective The aim of this study was to analyze the chief complaints of psychological crisis hotlines during the coronavirus disease 2019 (COVID-19) pandemic in Jiangsu, China, and to summarize the psychological characteristics of the public during the different stages of COVID-19. Methods The chief complaints of calls to the psychological crisis hotline from 27 January 2020 to 30 June 2020. A total of 578 calls were extracted and grouped using thematic analysis into categories. After statistical analysis, the monthly and three-period trends were observed dynamically to determine whether there were statistical differences in the proportion of specific chief complaints over the phases. Results There were a total of 495 cases of psychological problems or physical discomfort, accounting for 85.64% of the total sample number of hotline calls related to the pandemic. The numbers of callers with anxiety, depression, obsessive-compulsive symptoms, illness anxiety, insomnia, and physical discomfort were 370 (64.01%), 103 (17.99%), 33 (5.71%), 36 (6.23%), 51 (8.82%), and 72 (12.46%), respectively, and 83 (14.36%) callers consulted other problems. The monthly main complaints showed a fluctuating trend, and each main complaint peaked at different stages. The main complaints during the three stages had distinct features, respectively, and the proportions of calls for the specific complaints differed statistically over the phases. Conclusion Dynamic observation and qualitative analysis of psychological crisis hotline data might indicate dynamic changes and accordingly provide guidance for online crisis intervention when other public health crises occur.

Time series clustering of COVID-19 pandemic-related data

The COVID-19 pandemic continues to impact daily life worldwide. It would be helpful and valuable if we could obtain valid information from the COVID-19 pandemic sequential data itself for characterizing the pandemic. Here, we aim to demonstrate that it is feasible to analyze the patterns of the pandemic using a time-series clustering approach. In this work, we use dynamic time warping distance and hierarchical clustering to cluster time series of daily new cases and deaths from different countries into four patterns. It is found that geographic factors have a large but not decisive influence on the pattern of pandemic development. Moreover, the age structure of the population may also influence the formation of cluster patterns. Our proven valid method may provide a different but very useful perspective for other scholars and researchers.

Three-dose vaccination-induced immune responses protect against SARS-CoV-2 Omicron BA.2: a population-based study in Hong Kong.

Background: The ongoing outbreak of SARS-CoV-2 Omicron BA.2 infections in Hong Kong, the model city of universal masking of the world, has resulted in a major public health crisis. Although the third vaccination resulted in strong boosting of neutralization antibody, vaccine efficacy and correlate of immune protection against the major circulating Omicron BA.2 remain to be investigated. Methods: We investigated the vaccine efficacy against the Omicron BA.2 breakthrough infection among 470 public servants who had received different SARS-CoV-2 vaccine regimens including two-dose BNT162b2 (2 × BNT, n = 169), three-dose BNT162b2 (3 × BNT, n = 168), two-dose CoronaVac (2 × CorV, n = 34), three-dose CoronaVac (3 × CorV, n = 67) and third-dose BNT162b2 following 2 × CorV (2 × CorV+1BNT, n = 32). Humoral and cellular immune responses after three-dose vaccination were further characterized and correlated with clinical characteristics of BA.2 infection. Findings: During the BA.2 outbreak, 27.7% vaccinees were infected. The timely third-dose vaccination provided significant protection with lower incidence rates of breakthrough infections (2 × BNT 46.2% vs 3 × BNT 13.1%, p < 0.0001; 2 × CorV 44.1% vs 3 × CorV 19.4%, p = 0.003). Investigation of immune responses on blood samples derived from 90 subjects in three-dose vaccination cohorts collected before the BA.2 outbreak revealed that the third-dose vaccination activated spike (S)-specific memory B cells and Omicron cross-reactive T cell responses, which correlated with reduced frequencies of breakthrough infections and disease severity rather than with types of vaccines. Moreover, the frequency of S-specific activated memory B cells was significantly lower in infected vaccinees than uninfected vaccinees before vaccine-breakthrough infection whereas IFN-γ+ CD4 T cells were negatively associated with age and viral clearance time. Critically, BA.2 breakthrough infection boosted cross-reactive memory B cells with enhanced cross-neutralizing antibodies to Omicron sublineages, including BA.2.12.1 and BA.4/5, in all vaccinees tested. Interpretation: Our results imply that the timely third vaccination and immune responses are likely required for vaccine-mediated protection against Omicron BA.2 pandemic. Although BA.2 conferred the highest neutralization resistance compared with variants of concern tested before the emergence of BA.2.12.1 and BA.4/5, the third dose vaccination-activated S-specific memory B cells and Omicron cross-reactive T cell responses contributed to reduced frequencies of breakthrough infection and disease severity. Neutralizing antibody potency enhanced by BA.2 breakthrough infection in vaccinees with prior 3 doses of CoronaVac or BNT162b2 may reduce the risk of infection against ongoing BA.2.12.1 and BA.4/5. Funding: Hong Kong Research Grants Council Collaborative Research Fund, Health and Medical Research Fund, Wellcome Trust, Shenzhen Science and Technology Program, the Health@InnoHK, Innovation and Technology Commission of Hong Kong, China, National Program on Key Research Project, Emergency Key Program of Guangzhou Laboratory, donations from the Friends of Hope Education Fund and the Hong Kong Theme-Based Research Scheme.

Dynamic observation and qualitative analysis of a psychological crisis hotline during the COVID-19 pandemic.

Objective: The aim of this study was to analyze the chief complaints of psychological crisis hotlines during the coronavirus disease 2019 (COVID-19) pandemic in Jiangsu, China, and to summarize the psychological characteristics of the public during the different stages of COVID-19. Methods: The chief complaints of calls to the psychological crisis hotline from 27 January 2020 to 30 June 2020. A total of 578 calls were extracted and grouped using thematic analysis into categories. After statistical analysis, the monthly and three-period trends were observed dynamically to determine whether there were statistical differences in the proportion of specific chief complaints over the phases. Results: There were a total of 495 cases of psychological problems or physical discomfort, accounting for 85.64% of the total sample number of hotline calls related to the pandemic. The numbers of callers with anxiety, depression, obsessive-compulsive symptoms, illness anxiety, insomnia, and physical discomfort were 370 (64.01%), 103 (17.99%), 33 (5.71%), 36 (6.23%), 51 (8.82%), and 72 (12.46%), respectively, and 83 (14.36%) callers consulted other problems. The monthly main complaints showed a fluctuating trend, and each main complaint peaked at different stages. The main complaints during the three stages had distinct features, respectively, and the proportions of calls for the specific complaints differed statistically over the phases. Conclusion: Dynamic observation and qualitative analysis of psychological crisis hotline data might indicate dynamic changes and accordingly provide guidance for online crisis intervention when other public health crises occur.

Influence of empathy on work alienation among Chinese nurses during the COVID-19 pandemic: The mediating effect of ego depletion.

Background: Nurses' work alienation has become increasingly serious due to the increase in workload and risk during the coronavirus disease 2019 (COVID-19). However, no studies have investigated the link between empathy, ego depletion, and work alienation among Chinese nurses. The present study aimed to evaluate Chinese nurses' empathy, ego depletion, and work alienation and to examine whether nurses' ego depletion mediates the relationship between empathy and work alienation. Methods: This was a descriptive, cross-sectional study involving 353 nurses from Shaanxi. The Jefferson Scale of Empathy-Health Professionals, Self-Regulating Fatigue Scale and Work Alienation Questionnaire were used to collect data through an online survey. Structural equation modeling was conducted to analyze the mediating model. Results: Work alienation was negatively correlated with empathy (r = -0.305, p < 0.01) and positively correlated with ego depletion (r = 0.652, p < 0.01). Empathy was negatively correlated with ego depletion (r = -0.325, p < 0.01). Empathy can directly predict work alienation (ß = -0.263, p < 0.01), while ego depletion has a mediating effect between empathy and work alienation (ß = -0.309, p < 0.01), and the mediating effect accounts for 54.02% of the total effect. Conclusion: Nurses' work alienation was at a moderate-to-high level. Improving empathy can reduce work alienation through less ego depletion. Nursing managers should discover nurses' work alienation as soon as possible. Interventions to improve empathy can help replenish nurses' psychological resources, thereby reducing ego depletion and work alienation.

Network structure of family function and self-management in patients with early chronic kidney disease amid the COVID-19 pandemic.

Background: Family function plays a pivotal role in self-management among patients with early chronic kidney disease (CKD), which has been especially important during the COVID-19 pandemic. Previous studies have investigated the relationships between family function and self-management using total scores through self-report questionnaires while ignoring the different components in both family function and self-management. The specific objective of this study was to explore the network structure of family function and self-management at the component level. Methods: A total of 360 patients with early CKD from three tertiary hospitals were enrolled in our cross-sectional survey from September to December 2021 in China. Components of family function were measured by the Family Adaptation Partnership Growth and Resolve Index, and components of self-management were measured by the Chronic Kidney Disease Self-management Instrument. Network analysis was used to establish the network structure. Results: Edges across the community of family function and self-management were mainly positive. Edges between F3 "Growth" and M1 "Self-integration", F2 "Partnership" and M3 "Seeking social support," F5 "Resolve" and M3 "Seeking social support" were the strongest. F3 "Growth" had the greatest positive bridge expected influence of family function community (0.12), and M3 "Seeking social support" had the greatest positive bridge expected influence of self-management community (0.16). Conclusion: We explored the potential pathways between different components of family function and self-management among patients with early CKD during the COVID-19 pandemic and found fine-grained relationships between them. The two nodes F3 "Growth" and M3 "Seeking social support" may provide a new idea from the perspective of family function for interventions to improve self-management.

Network structure of family function and self-management in patients with early chronic kidney disease amid the COVID-19 pandemic

Background Family function plays a pivotal role in self-management among patients with early chronic kidney disease (CKD), which has been especially important during the COVID-19 pandemic. Previous studies have investigated the relationships between family function and self-management using total scores through self-report questionnaires while ignoring the different components in both family function and self-management. The specific objective of this study was to explore the network structure of family function and self-management at the component level. Methods A total of 360 patients with early CKD from three tertiary hospitals were enrolled in our cross-sectional survey from September to December 2021 in China. Components of family function were measured by the Family Adaptation Partnership Growth and Resolve Index, and components of self-management were measured by the Chronic Kidney Disease Self-management Instrument. Network analysis was used to establish the network structure. Results Edges across the community of family function and self-management were mainly positive. Edges between F3 "Growth” and M1 "Self-integration”, F2 "Partnership” and M3 "Seeking social support,” F5 "Resolve” and M3 "Seeking social support” were the strongest. F3 "Growth” had the greatest positive bridge expected influence of family function community (0.12), and M3 "Seeking social support” had the greatest positive bridge expected influence of self-management community (0.16). Conclusion We explored the potential pathways between different components of family function and self-management among patients with early CKD during the COVID-19 pandemic and found fine-grained relationships between them. The two nodes F3 "Growth” and M3 "Seeking social support” may provide a new idea from the perspective of family function for interventions to improve self-management.

A Monoclonal Antibody Targeting C-Terminal Domain of Transmissible Gastroenteritis Virus Spike Protein.

The structure and function of the C-terminus domain (CTD) of porcine transmissible gastroenteritis virus (TGEV) spike protein remain largely unknown, thereby a specific monoclonal antibody (MAb) allows us to fully understand this domain. In this study, we developed a murine MAb against CTD of TGEV spike protein, as evidenced by the results of indirect fluorescent assay, Western blotting, and fluorescence-activated cell sorter. Further study showed that the MAb is able to exclusively recognize a 12-residue peptide (FKNVSDGVIYSV) derived from CTD of TGEV spike protein. This MAb can be used to elucidate the potential function of CTD of TGEV spike in virus attachment and entry, and warrants further intensive investigation.

Neutralizing antibodies against SARS-CoV-2 are higher but decline faster in mRNA vaccinees compared to individuals with natural infection.

BACKGROUND: Waning protection against emerging SARS-CoV-2 variants by pre-existing antibodies elicited due to current vaccination or natural infection is a global concern. Whether this is due to the waning of immunity to SARS-COV-2 remains unclear. AIM: We aimed to investigate the dynamics of antibody isotype responses among vaccinated naïve (VN) and naturally infected (NI) individuals. METHODS: We followed up antibody levels in COVID-19 mRNA-vaccinated subjects without prior infection (VN, n = 100) in two phases: phase-I (P-I) at ~ 1.4 and phase-II (P-II) at ~ 5.3 months. Antibody levels were compared to those of unvaccinated and naturally infected subjects (NI, n = 40) at ~ 1.7 (P-1) and 5.2 (P-II) months post-infection. Neutralizing antibodies (NTAb), anti-S-RBD-IgG, -IgM, and anti-S-IgA isotypes were measured. RESULTS: The VN group elicited significantly greater antibody responses (p < 0.001) than the NI group at P-I, except for IgM. In the VN group, a significant waning in antibody response was observed in all isotypes. There was about ~ a 4-fold decline in NTAb levels (p < 0.001), anti-S-RBD-IgG (~5-folds, p < 0.001), anti-S-RBD-IgM (~6-folds, p < 0.001), and anti-S1-IgA (2-folds, p < 0.001). In the NI group, a significant but less steady decline was notable in S-RBD-IgM (~2-folds, p < 0.001), and a much smaller but significant difference in NTAb (<2-folds, p < 0.001) anti-S-RBD IgG (<2-folds, p = 0.005). Unlike the VN group, the NI group mounted a lasting anti-S1-IgA response with no significant decline. Anti-S1-IgA, which were ~ 3 folds higher in VN subjects compared to NI in P-1 (p < 0.001), dropped to almost the same levels, with no significant difference observed between the two groups in P-II. CONCLUSION: While double-dose mRNA vaccination boosted antibody levels, vaccinated individuals' 'boost' was relatively short-lived.

Evaluation of commercially available fully automated and ELISA-based assays for detecting anti-SARS-CoV-2 neutralizing antibodies.

Rapid and accurate measurement of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2)-specific neutralizing antibodies (nAbs) is paramount for monitoring immunity in infected and vaccinated subjects. The current gold standard relies on pseudovirus neutralization tests which require sophisticated skills and facilities. Alternatively, recent competitive immunoassays measuring anti-SARS-CoV-2 nAbs are proposed as a quick and commercially available surrogate virus neutralization test (sVNT). Here, we report the performance evaluation of three sVNTs, including two ELISA-based assays and an automated bead-based immunoassay for detecting nAbs against SARS-CoV-2. The performance of three sVNTs, including GenScript cPass, Dynamiker, and Mindray NTAb was assessed in samples collected from SARS-CoV-2 infected patients (n = 160), COVID-19 vaccinated individuals (n = 163), and pre-pandemic controls (n = 70). Samples were collected from infected patients and vaccinated individuals 2-24 weeks after symptoms onset or second dose administration. Correlation analysis with pseudovirus neutralization test (pVNT) and immunoassays detecting anti-SARS-CoV-2 binding antibodies was performed. Receiver operating characteristic (ROC) curve analysis was generated to assess the optimal threshold for detecting nAbs by each assay. All three sVNTs showed an excellent performance in terms of specificity (100%) and sensitivity (100%, 97.0%, and 97.1% for GenScript, Dynamiker, and Mindray, respectively) in samples collected from vaccinated subjects. GenScript demonstrated the strongest correlation with pVNT (r = 0.743, R2 = 0.552), followed by Mindray (r = 0.718, R2 = 0.515) and Dynamiker (r = 0.608, R2 = 0.369). Correlation with anti-SARS-CoV-2 binding antibodies was variable, but the strongest correlations were observed between anti-RBD IgG antibodies and Mindray (r = 0.952, R2 = 0.907). ROC curve analyses demonstrated excellent performance for all three sVNT assays in both groups, with an AUC ranging between 0.99 and 1.0 (p < 0.0001). Also, it was shown that the manufacturer's recommended cutoff values could be modified based on the tested cohort without significantly affecting the sVNT performance. The sVNT provides a rapid, low-cost, and scalable alternative to conventional neutralization assays for measuring and expanding nAbs testing across various research and clinical settings. Also, it could aid in evaluating actual protective immunity at the population level and assessing vaccine effectiveness to lay a foundation for boosters' requirements.

Influence of positive and negative affect on self-management among patients with early chronic kidney disease during the COVID-19 pandemic: The mediating and suppressing effect of ego depletion

Background Self-management in patients with early chronic kidney disease (CKD) can effectively delay damage to renal function. However, with the continuous spread of COVID-19, patients cannot receive timely treatment, which can lead to different affects, resulting in ego depletion and serious challenges to self-management. This study aimed to investigate the mediating and suppressing roles of ego depletion on the relationship between positive and negative affect and self-management among patients with early CKD during the COVID-19 pandemic in China. Methods A total of 383 patients with early CKD from three tertiary hospitals were enrolled by convenience sampling in our cross-sectional study from September 2021 to March 2022. Participants completed the Sociodemographic Questionnaire, Positive Affect and Negative Affect Scale, Self-Regulating Fatigue Scale and Chronic Kidney Disease Self-Management Instrument. A structural equation model was conducted to test the mediating and suppressing effects of ego depletion on the relationship between positive and negative affect and self-management. Results The average score of the participants' self-management was 84.54 (SD: 19.72), and nearly 60% of them were at low and moderate levels. The mediating effect of positive affect on self-management through ego depletion was significant (β = 0.248, 95% CI: 0.170 to 0.376), accounting for 53.22% of the total effect. The suppressing effect of negative affect on self-management through ego depletion was significant (β = −0.191, 95% CI: −0.310 to −0.118), and the absolute value of the ratio of the suppressing effect to the direct effect was 66.55%. Conclusions Ego depletion partially mediated the relationship between positive affect and self-management while suppressing the relationship between negative affect and self-management among patients with early CKD during the COVID-19 pandemic. The reduction of patients' ego depletion must be taken as the intervention target to improve self-management and delay the progression of CKD.

Naturally occurring spike mutations influence the infectivity and immunogenicity of SARS-CoV-2.

Mutations in SARS-CoV-2 variants of concern (VOCs) have enhanced transmissibility and immune evasion with respect to current vaccines and neutralizing antibodies (NAbs). How naturally occurring spike mutations affect the infectivity and antigenicity of VOCs remains to be investigated. The entry efficiency of individual spike mutations was determined in vitro using pseudotyped viruses. BALB/c mice were immunized with 2-dose DNA vaccines encoding B.1.1.7, B.1.351, B.1.1.529  and their single mutations. Cellular and humoral immune responses were then compared to determine the impact of individual mutations on immunogenicity. In the B.1.1.7 lineage, Del69-70 and Del 144 in NTD, A570D and P681H in SD1 and S982A and D1118H in S2 significantly increased viral entry, whereas T716I resulted in a decrease. In the B.1.351 lineage, L18F and Del 242-244 in the NTD, K417N in the RBD and A701V in S2 also increased viral entry. S982A weakened the generation of binding antibodies. All sera showed reduced cross-neutralization activity against B.1.351, B.1.617.2 (Delta) and B.1.1.529 (Omicron BA.1). S982A, L18F, and Del 242-244 hindered the induction of cross-NAbs, whereas Del 69-70, Del144, R246I, and K417N showed the opposite effects. B.1.351 elicited adequate broad cross-NAbs against both B.1.351 and B.1.617.2. All immunogens tested, however, showed low neutralization against circulating B.1.1.529. In addition, T-cell responses were unlikely affected by mutations tested in the spike. We conclude that individual spike mutations influence viral infectivity and vaccine immunogenicity. Designing VOC-targeted vaccines is likely necessary to overcome immune evasion from current vaccines and neutralizing antibodies.

Real-time detection of viruses in aerosols with weak light imaging based on Tesla discharge

The analysis and detection of nucleic acid and specific antigens and antibodies are the most basic technologies for virus monitoring. However, the potential window for applying these technologies exists within a late specific period in the early monitoring and control of unknown viruses, especially human and animal pathogenic viruses transmitted via aerosols, e.g., SARS-CoV-2 and its variants. This is because early, real-time, and convenient monitoring of unknown viruses in the air or exhaled gas cannot be directly achieved through existing technologies. Herein, we report a weak light spectral imaging technology based on Tesla discharge (termed T-DAI) that can quickly monitor for viruses in real time in simulated aerosols with 71% sensitivity and 76% specificity for aerosol virus concentrations exceeding approximately 2800 vp/μl. This technology realizes the rapid detection of low concentrations of viruses in aerosols and could provide an important means for predicting, screening, and monitoring unknown or pandemic pathogenic viruses in the air or exhaled breath of humans and animals. [ FROM AUTHOR] Copyright of Applied Physics Letters is the property of American Institute of Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

The world uncertainty index and GDP growth rate

Based on the content of the novel World Uncertainty Index (WUI), this paper examines whether the World Uncertainty Index has the predictability for the U.S. gross domestic product growth rate. Empirical results show that the information of WUI indices is able to predict GDP growth rate, especially the U.S. WUI indices such as USA WUI (frequency) and USA WUI (total number) indices. During the COVID-19 period, we find that all the WUI models can generate stronger forecasting ability for the GDP growth rate. Our paper tries to provide new evidence for predicting the GDP growth rate.

Epidemic Dynamics of a Fractional-Order SIR Weighted Network Model and Its Targeted Immunity Control

With outbreaks of epidemics, an enormous loss of life and property has been caused. Based on the influence of disease transmission and information propagation on the transmission characteristics of infectious diseases, in this paper, a fractional-order SIR epidemic model is put forward on a two-layer weighted network. The local stability of the disease-free equilibrium is investigated. Moreover, a conclusion is obtained that there is no endemic equilibrium. Since the elderly and the children have fewer social tiers, a targeted immunity control that is based on age structure is proposed. Finally, an example is presented to demonstrate the effectiveness of the theoretical results. These studies contribute to a more comprehensive understanding of the epidemic transmission mechanism and play a positive guiding role in the prevention and control of some epidemics.

Waning immune responses against SARS-CoV-2 variants of concern among vaccinees in Hong Kong.

BACKGROUND: Nearly 4 billion doses of the BNT162b2-mRNA and CoronaVac-inactivated vaccines have been administrated globally, yet different vaccine-induced immunity against SARS-CoV-2 variants of concern (VOCs) remain incompletely investigated. METHODS: We compare the immunogenicity and durability of these two vaccines among fully vaccinated Hong Kong people. FINDINGS: Standard BNT162b2 and CoronaVac vaccinations were tolerated and induced neutralizing antibody (NAb) (100% and 85.7%) and spike-specific CD4 T cell responses (96.7% and 82.1%), respectively. The geometric mean NAb IC50 and median frequencies of reactive CD4 subsets were consistently lower among CoronaVac-vaccinees than BNT162b2-vaccinees. CoronaVac did not induce measurable levels of nucleocapsid protein-specific IFN-γ+ CD4+ T or IFN-γ+ CD8+ T cells compared with unvaccinated. Against VOCs, NAb response rates and geometric mean IC50 titers against B.1.617.2 (Delta) and B.1.1.529 (Omicron) were significantly lower for CoronaVac (50%, 23.2 and 7.1%, <20) than BNT162b2 (94.1%, 131 and 58.8%, 35.0), respectively. Three months after vaccinations, NAbs to VOCs dropped near to detection limit, along with waning memory T cell responses, mainly among CoronaVac-vaccinees. INTERPRETATION: Our results indicate that vaccinees especially CoronaVac-vaccinees with significantly reduced NAbs may probably face higher risk to pandemic VOCs breakthrough infection. FUNDING: This study was supported by the Hong Kong Research Grants Council Collaborative Research Fund (C7156-20GF and C1134-20GF); the Wellcome Trust (P86433); the National Program on Key Research Project of China (Grant 2020YFC0860600, 2020YFA0707500 and 2020YFA0707504); Shenzhen Science and Technology Program (JSGG20200225151410198 and JCYJ20210324131610027); HKU Development Fund and LKS Faculty of Medicine Matching Fund to AIDS Institute; Hong Kong Innovation and Technology Fund, Innovation and Technology Commission and generous donation from the Friends of Hope Education Fund. Z.C.'s team was also partly supported by the Theme-Based Research Scheme (T11-706/18-N).