Cultural traits or social norms? Both responsibilism and norms linked to accepting covid-19 vaccine

We studied the factors that influence attitudes toward the COVID-19 vaccine by testing 1872 people across 29 provinces in China. We investigated an individual trait (responsibilism) and two situational factors (a descriptive norm and an injunctive norm). Responsibilism is a version of collectivism that emphasizes tight social ties and responsibilities in close relationships. Responsibilism and perceptions of strong social norms predicted acceptance of the COVID-19 vaccine. The data also revealed an interplay between responsibilism and social norms. People high in responsibilism accepted the vaccine regardless of social norms. But people low in responsibilism were wary of the vaccine, unless they perceived strong injunctive norms. These findings contribute to the research on psychological factors behind vaccine hesitancy. The findings could help provide a roadmap for public health efforts to encourage vaccines. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

Orthodontic care in orthodontic patients during the COVID-2019 pandemic: emergency, emergency response and orthodontic treatment preference.

BACKGROUND: The objective of this study was to investigate the characteristics of emergencies and the requirement for emergency treatment after the suspension of orthodontic appointments. The attitude towards orthodontic treatment preference was evaluated as well, including receiving orthodontic treatment and the preference for orthodontic appliances. SUBJECTS AND METHODS: An electronic questionnaire was distributed to the patients, including 4 sections: Section 1 - demographic and basic information; Section 2 - the characteristics of emergencies and emergency treatment requirements; Section 3 - the NRS-11 for pain and Manchester Orofacial Pain Disability Scale used to evaluate the intensity of orofacial pain and disability; and Section 4 - attitudes towards receiving orthodontic treatment and appliance preference. Descriptive statistics, Pearson's chi-square test, Wilcoxon's rank-sum test and stepwise generalized linear model (GLM) were performed with significance set at P < 0.05. RESULT: Most participants' (91.61%) follow-up appointments were suspended. The emergency rate and emergency treatment requirements were not different between the fixed appliance (FA) and clear aligner (CA) groups. Patients who reported emergencies (P < 0.01) in the FA group (P < 0.05) and some emergencies in the FA (P < 0.05) suffered worse pain and disability. More FA participants preferred alternative appliances (P < 0.05) due to pain and disability (P < 0.05). CONCLUSION: FA patients' emergencies caused worse pain and disability when orthodontic appointments were suspended. Pain and disability were not the causes of emergency treatment requirements. The CA group seemed to show a tendency towards orthodontic appliance preference, which was an ideal modality to weather the epidemic, combined with telemedicine.

Respiratory immune status and microbiome in recovered COVID-19 patients revealed by metatranscriptomic analyses.

Coronavirus disease 2019 (COVID-19) is currently a severe threat to global public health, and the immune response to COVID-19 infection has been widely investigated. However, the immune status and microecological changes in the respiratory systems of patients with COVID-19 after recovery have rarely been considered. We selected 72 patients with severe COVID-19 infection, 57 recovered from COVID-19 infection, and 65 with non-COVID-19 pneumonia, for metatranscriptomic sequencing and bioinformatics analysis. Accordingly, the differentially expressed genes between the infected and other groups were enriched in the chemokine signaling pathway, NOD-like receptor signaling pathway, phagosome, TNF signaling pathway, NF-kappa B signaling pathway, Toll-like receptor signaling pathway, and C-type lectin receptor signaling pathway. We speculate that IL17RD, CD74, and TNFSF15 may serve as disease biomarkers in COVID-19. Additionally, principal coordinate analysis revealed significant differences between groups. In particular, frequent co-infections with the genera Streptococcus, Veillonella, Gemella, and Neisseria, among others, were found in COVID-19 patients. Moreover, the random forest prediction model with differential genes showed a mean area under the curve (AUC) of 0.77, and KCNK12, IL17RD, LOC100507412, PTPRT, MYO15A, MPDZ, FLRT2, SPEG, SERPINB3, and KNDC1 were identified as the most important genes distinguishing the infected group from the recovered group. Agrobacterium tumefaciens, Klebsiella michiganensis, Acinetobacter pittii, Bacillus sp. FJAT.14266, Brevundimonas naejangsanensis, Pseudopropionibacterium propionicum, Priestia megaterium, Dialister pneumosintes, Veillonella rodentium, and Pseudomonas protegens were selected as candidate microbial markers for monitoring the recovery of COVID patients. These results will facilitate the diagnosis, treatment, and prognosis of COVID patients recovering from severe illness.

Transmission of SARS-CoV-2 Omicron Variant under a Dynamic Clearance Strategy in Shandong, China.

SARS-CoV-2 Omicron caused a large wave of COVID-19 cases in China in spring 2022. Shandong was one of the most affected regions during this epidemic yet was also among those areas that were able to quickly contain the transmission. We aimed to investigate the origin, genetic diversity, and transmission patterns of the Omicron epidemic in Shandong under a dynamic clearance strategy. We generated 1,149 Omicron sequences, performed phylogenetic analysis, and interpreted results in the context of available epidemiological information. We observed that there were multiple introductions of distinct Omicron sublineages into Shandong from foreign countries and other regions in China, while a small number of introductions led to majority of local cases. We found evidence suggesting that some local clusters were potentially associated with foreign imported cases. Superspreading events and cryptic transmissions contributed to the rapid spread of this epidemic. We identified a BA.1.1 genome with the R493Q reversion mutation in the spike receptor binding domain, potentially associated with an escape from vaccine and Omicron infection elicited neutralizing immunity. Our findings illustrated how the dynamic clearance strategy constrained this epidemic's size, duration, and geographical distribution. IMPORTANCE Starting in March 2022, the Omicron epidemic caused a large wave of COVID-19 cases in China. Shandong was one of the most affected regions during this epidemic but was also among those areas that were able to quickly contain the transmission. We investigated the origin, genetic diversity, and transmission patterns of Omicron epidemic in Shandong under a dynamic clearance strategy. We found that there were multiple introductions of distinct Omicron sublineages into Shandong from foreign countries and other regions in China, while a small number of introductions led to most local cases. We found evidence suggesting that some local clusters were associated with foreign imported cases. Superspreading events and cryptic transmissions contributed to the rapid spread of this epidemic. Our study illustrated the transmission patterns of Omicron epidemic in Shandong and provided a looking glass onto this epidemic in China.

A comment-driven evidence appraisal approach to promoting research findings into practice when only uncertain evidence is available.

BACKGROUND: Comments in PubMed are usually short papers for supporting or refuting claims, or discussing methods and findings in original articles. This study aims to explore whether they can be used as a quick and reliable evidence appraisal instrument for promoting research findings into practice, especially in emergency situations such as COVID-19 in which only missing, incomplete or uncertain evidence is available. METHODS: Evidence-comment networks (ECNs) were constructed by linking COVID-19-related articles to the commentaries (letters, editorials or brief correspondence) they received. PubTator Central was used to extract entities with a high volume of comments from the titles and abstracts of the articles. Among them, six drugs were selected, and their evidence assertions were analysed by exploring the structural information in the ECNs as well as the sentiment of the comments (positive, negative, neutral). Recommendations in WHO guidelines were used as the gold standard control to validate the consistency, coverage and efficiency of comments in reshaping clinical knowledge claims. RESULTS: The overall positive/negative sentiments of comments were aligned with recommendations for/against the corresponding treatments in the WHO guidelines. Comment topics covered all significant points of evidence appraisal and beyond. Furthermore, comments may indicate the uncertainty regarding drug use for clinical practice. Half of the critical comments emerged 4.25 months earlier on average than the guideline release. CONCLUSIONS: Comments have the potential as a support tool for rapid evidence appraisal as they have a selection effect by appraising the benefits, limitations and other clinical practice issues of concern in existing evidence. We suggest as a future direction an appraisal framework based on the comment topics and sentiment orientations to leverage the potential of scientific commentaries supporting evidence appraisal and decision-making.

Effect of extreme temperatures on asthma hospital visits: Modification by event characteristics and healthy behaviors.

Although ambient temperature has been linked to asthma exacerbation, impacts associated with extreme temperature events remain unclear. This study aims to identify the events characteristics that elevate risk of asthma hospital visits, and to assess whether healthy behavior changes due to the COVID-19 prevention and control policy may modify the relationships. Data of asthma hospital visits from all medical facilities in Shenzhen, China during 2016-2020 were assessed in relation to extreme temperature events using a distributed lag model. Stratified analysis was conducted by gender, age and hospital department to identify susceptible populations. Through events defined by various duration days and temperature thresholds, we explored the modification by events intensity, length, occurrence time and healthy behaviors. The cumulative relative risk of asthma during heat waves compared to other days was 1.06 (95%CI: 1.00-1.13) and for cold spells was 1.17 (95%CI: 1.05-1.30), and that of males and school-aged children were generally higher than other sub-groups. There were significant effects of heat waves and cold spells on asthma hospital visits when the mean temperature was above 90th percentile (30 °C) and below 10th percentile (14 °C) respectively, and the relative risks were higher when events lasted longer, became stronger, occurred in daytime and in early summer or winter. During the healthy behaviors maintaining period, the risk of heat waves increased whilst the risk of cold spells reduced. Extreme temperatures may pose considerable impact on asthma and the health effect can be modified by the event characteristics and anti-epidemic healthy behaviors. Strategies of asthma control should consider the heightened threats of the intense and frequent extreme temperature events in the context of climate change.

Ocular Adverse Events after Inactivated COVID-19 Vaccination.

PURPOSE: To report the clinical characteristics of ocular adverse events that have occurred, in China, after vaccination with inactivated COVID-19 vaccines. METHODS: A retrospective cross-sectional observational study was conducted of ocular disorders that occurred within 15 days from any dose of an inactivated COVID-19 vaccine. Information on gender, age, the interval between the vaccination and ocular symptoms, laterality, duration of the ocular symptoms, primary visual acuity, and clinical diagnosis were retrospectively collected. RESULTS: Twenty-four patients were involved in the study, including 15 females and 9 males, with a mean age of 41 ± 16 years (range of 8-71 years). The patients all denied a prior history of COVID-19 infection. Ocular adverse events occurred after the first dose of vaccine in 18 patients and, after the second or third doses, in six patients. The interval between vaccination with the inactivated COVID-19 vaccine and ocular symptoms was 6 ± 5 days; six patients were bilaterally involved and 18 patients were unilaterally involved. Regarding the diagnosis, 10 patients were diagnosed with white dot syndrome (WDS), 9 patients were diagnosed with uveitis, and 5 patients were diagnosed with retinal vascular disorders. The ages of patients with WDS were younger than those with uveitis or retinal vascular disorders (32 ± 10 vs. 48 ± 18, p < 0.05). For patients diagnosed with WDS, the best-corrected visual acuity (BCVA) was 0.74 ± 0.73 LogMAR. For patients diagnosed with retinal vascular disorders or uveitis, the BCVA was 1.44 ± 1.26 LogMAR. There was no significant difference (p > 0.05). CONCLUSIONS: A relationship cannot be established between inactivated COVID-19 vaccines and ocular disorders; therefore, further investigation of the clinical spectrum of ocular adverse events after vaccination with an inactivated COVID-19 vaccine is necessary.

Pre-Clinical Development of a Potent Neutralizing Antibody MW3321 With Extensive SARS-CoV-2 Variants Coverage.

Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, several variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged and have consistently replaced the previous dominant variant. Therapeutics against variants of SARS-CoV-2 are urgently needed. Ideal SARS-CoV-2 therapeutic antibodies would have high potency in viral neutralization against several emerging variants. Neutralization antibodies targeting SARS-CoV-2 could provide immediate protection after SARS-CoV-2 infection, especially for the most vulnerable populations. In this work, we comprehensively characterize the breadth and efficacy of SARS-CoV-2 RBD-targeting fully human monoclonal antibody (mAb) MW3321. MW3321 retains full neutralization activity to all tested 12 variants that have arisen in the human population, which are assigned as VOC (Variants of Concern) and VOI (Variants of Interest) due to their impacts on public health. Escape mutation experiments using replicating SARS-CoV-2 pseudovirus show that escape mutants were not generated until passage 6 for MW3321, which is much more resistant to escape mutation compared with another clinical staged SARS-CoV-2 neutralizing mAb MW3311. MW3321 could effectively reduce viral burden in hACE2-transgenic mice challenged with either wild-type or Delta SARS-CoV-2 strains through viral neutralization and Fc-mediated effector functions. Moreover, MW3321 exhibits a typical hIgG1 pharmacokinetic and safety profile in cynomolgus monkeys. These data support the development of MW3321 as a monotherapy or cocktail against SARS-CoV-2-related diseases.

COVID-19 vaccination hesitancy and safety among adult people with epilepsy in eastern China.

OBJECTIVE: This study assesses the hesitancy and safety of vaccination administration for the novel 2019 Coronavirus Disease (COVID-19) among adult people with epilepsy (PWE). METHODS: We recruited adult PWE who visited the outpatient epilepsy clinic from August 2021 to February 2022. We administered a structured questionnaire and a face-to-face interview regarding demographic factors, epilepsy characteristics, and relevant vaccine issues to all patients. Factors related to receiving a vaccine and epilepsy-related events after vaccination were then analyzed. RESULTS: A total of 501 PWE were surveyed; 288 were unvaccinated and 213 were vaccinated. Patients without jobs (OR: 0.59; 95% CI: 0.37-0.95, p = 0.03) were less likely to receive the vaccine compared to students or those with jobs. Other factors associated with vaccination were a higher number of anti-seizure medications (OR: 0.72; 95% CI: 0.55-0.95, p = 0.02) and a lower pre-vaccine seizure frequency (OR: 2.21; 95% CI: 1.06-4.59, p = 0.03). Of the 213 vaccinated patients, 10 (4.70%) reported at least one local and/or systemic side effect. Most patients (92.50%) did not report worse seizures within one month of vaccination. Poor ASM adherence (OR: 15.06; 95% CI: 1.75-129.87, p = 0.01) and fatigue/stimulant drinks such as caffeine (OR: 50.59; 95% CI: 7.57-337.94, p < 0.01) were significantly associated with seizure worsening within one month of receiving the COVID-19 vaccination. CONCLUSION: Almost two-fifths of patients with adult PWE have received a COVID-19 vaccine. Attention should be paid to educating epilepsy patients without jobs on the significance and safety of the vaccine. There was a low risk of seizure worsening in the short term after vaccination in PWE.

Impacts of delta and omicron variants on inactivated SARS-CoV-2 vaccine-induced T cell responses in patients with autoimmune diseases and healthy controls.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes coronavirus disease 2019 (COVID-19), which is still devastating economies and communities globally. The increasing infections of variants of concern (VOCs) in vaccinated population have raised concerns about the effectiveness of current vaccines. Patients with autoimmune diseases (PAD) under immunosuppressant treatments are facing higher risk of infection and potentially lower immune responses to SARS-CoV-2 vaccination. METHODS: Blood samples were collected from PAD or healthy controls (HC) who finished two or three doses of inactivated vaccines. Spike peptides derived from wild-type strain, delta, omicron BA.1 were utilised to evaluate T cell responses and their cross-recognition of delta and omicron in HC and PAD by flow cytometry and ex vivo IFNγ-ELISpot. RESULTS: We found that inactivated vaccine-induced spike-specific memory T cells were long-lasting in both PAD and HC. These spike-specific T cells were highly conserved and cross-recognized delta and omicron. Moreover, a third inactivated vaccine expanded spike-specific T cells that responded to delta and omicron spike peptides substantially in both PAD and HC. Importantly, the polyfunctionality of spike-specific memory T cells was preserved in terms of cytokine and cytotoxic responses. Although the extent of T cell responses was lower in PAD after two-dose, T cell responses were boosted to a greater magnitude in PAD by the third dose, bringing comparable spike-specific T cell immunity after the third dose. CONCLUSION: Inactivated vaccine-induced spike-specific T cells remain largely intact against delta and omicron variants. This study expands our understanding of inactivated vaccine-induced T cell responses in PAD and HC, which could have important indications for vaccination strategy.

Respiratory immune status and microbiome in recovered COVID-19 patients revealed by metatranscriptomic analyses

Coronavirus disease 2019 (COVID-19) is currently a severe threat to global public health, and the immune response to COVID-19 infection has been widely investigated. However, the immune status and microecological changes in the respiratory systems of patients with COVID-19 after recovery have rarely been considered. We selected 72 patients with severe COVID-19 infection, 57 recovered from COVID-19 infection, and 65 with non-COVID-19 pneumonia, for metatranscriptomic sequencing and bioinformatics analysis. Accordingly, the differentially expressed genes between the infected and other groups were enriched in the chemokine signaling pathway, NOD-like receptor signaling pathway, phagosome, TNF signaling pathway, NF-kappa B signaling pathway, Toll-like receptor signaling pathway, and C-type lectin receptor signaling pathway. We speculate that IL17RD, CD74, and TNFSF15 may serve as disease biomarkers in COVID-19. Additionally, principal coordinate analysis revealed significant differences between groups. In particular, frequent co-infections with the genera Streptococcus, Veillonella, Gemella, and Neisseria, among others, were found in COVID-19 patients. Moreover, the random forest prediction model with differential genes showed a mean area under the curve (AUC) of 0.77, and KCNK12, IL17RD, LOC100507412, PTPRT, MYO15A, MPDZ, FLRT2, SPEG, SERPINB3, and KNDC1 were identified as the most important genes distinguishing the infected group from the recovered group. Agrobacterium tumefaciens, Klebsiella michiganensis, Acinetobacter pittii, Bacillus sp. FJAT.14266, Brevundimonas naejangsanensis, Pseudopropionibacterium propionicum, Priestia megaterium, Dialister pneumosintes, Veillonella rodentium, and Pseudomonas protegens were selected as candidate microbial markers for monitoring the recovery of COVID patients. These results will facilitate the diagnosis, treatment, and prognosis of COVID patients recovering from severe illness.

SARS-CoV-2 detection by targeting four loci of viral genome using graphene oxide and gold nanoparticle DNA biosensor.

The current COVID-19 pandemic outbreak poses a serious threat to public health, demonstrating the critical need for the development of effective and reproducible detection tests. Since the RT-qPCR primers are highly specific and can only be designed based on the known sequence, mutation sensitivity is its limitation. Moreover, the mutations in the severe acute respiratory syndrome ß-coronavirus (SARS-CoV-2) genome led to new highly transmissible variants such as Delta and Omicron variants. In the case of mutation, RT-qPCR primers cannot recognize and attach to the target sequence. This research presents an accurate dual-platform DNA biosensor based on the colorimetric assay of gold nanoparticles and the surface-enhanced Raman scattering (SERS) technique. It simultaneously targets four different regions of the viral genome for detection of SARS-CoV-2 and its new variants prior to any sequencing. Hence, in the case of mutation in one of the target sequences, the other three probes could detect the SARS-CoV-2 genome. The method is based on visible biosensor color shift and a locally enhanced electromagnetic field and significantly amplified SERS signal due to the proximity of Sulfo-Cyanine 3 (Cy3) and AuNPs intensity peak at 1468 cm-1. The dual-platform DNA/GO/AuNP biosensor exhibits high sensitivity toward the viral genome with a LOD of 0.16 ng/µL. This is a safe point-of-care, naked-eye, equipment-free, and rapid (10 min) detection biosensor for diagnosing COVID-19 cases at home using a nasopharyngeal sample.

Humoral immunity and transcriptome differences of COVID-19 inactivated vacciane and protein subunit vaccine as third booster dose in human.

Under the background of the severe human health and world economic burden caused by COVID-19, the attenuation of vaccine protection efficacy, and the prevalence and immune escape of emerging variants of concern (VOCs), the third dose of booster immunization has been put on the agenda. Systems biology approaches can help us gain new perspectives on the characterization of immune responses and the identification of factors underlying vaccine-induced immune efficacy. We analyzed the antibody signature and transcriptional responses of participants vaccinated with COVID-19 inactivated vaccine and protein subunit vaccine as a third booster dose. The results from the antibody indicated that the third booster dose was effective, and that heterologous vaccination with the protein subunit vaccine as a booster dose induced stronger humoral immune responses than the homologous vaccination with inactivated vaccine, and might be more effective against VOCs. In transcriptomic analysis, protein subunit vaccine induced more differentially expressed genes that were significantly associated with many important innate immune pathways. Both the homologous and heterologous boosters could increase the effectiveness against COVID-19, and compared with the inactivated vaccine, the protein subunit vaccine, mediated a stronger humoral immune response and had a more significant correlation with the innate immune function module, which provided certain data support for the third booster immunization strategy.

Public Health System and Socio-Economic Development Coupling Based on Systematic Theory: Evidence from China

This paper focus on the quantitative measurement of public health systems and its mismatch with socio-economic development. Based on systematic theory, we divide the public health system into four sub-systems: resource inputs, planning in decision-making, operations, and service outputs. We also provide a method to analyse the ability to match between the public health system and social-economic development by using the grey correlation and coupling method. Then we introduce data from China as a case of empirical research. The main findings are as follows: (1) China’s public health system has progressed from 2012 to 2019, and the development of China’s public health system is typically “input-driven”. Second, the level of public health management in China lacks sustainability. (2) The main reason for this problem is the mismatch between the central and local governments in China in terms of public health management authority. (3) Third, the coupling between China’s public health system and socio-economics development has shown a decreasing trend, which indicates an increasingly significant mismatch problem between public health and economic growth, urbanization, and population aging. Our study will enrich the understanding of the relationship between the public health system and socio-economics development.

Patient satisfaction and experience with digital consultations in community paediatrics during the COVID-19 pandemic

301 Table 1 301 Figure 1[Figure omitted. See PDF]ConclusionOverall, our surveys indicated a high level of satisfaction with the use of digital platforms in delivering consultations. However, whilst many families found the experience ‘helpful’, there were still technical issues with access to video devices and connection quality which risk increasing health inequalities. Questions were also raised by families with regards to selecting patients for whom digital consultations are appropriate. The plateau in non-attendance rates across the three time periods also demonstrated that digital consultation is by no means a solution for non-attendance. As a result of our surveys, which is now part of life QI, patients in our service, where appropriate, are now given a choice of mode of consultation. This shows patient driven change and ensures a patient-centred service.

Pre-Clinical Development of a Potent Neutralizing Antibody MW3321 With Extensive SARS-CoV-2 Variants Coverage

Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, several variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged and have consistently replaced the previous dominant variant. Therapeutics against variants of SARS-CoV-2 are urgently needed. Ideal SARS-CoV-2 therapeutic antibodies would have high potency in viral neutralization against several emerging variants. Neutralization antibodies targeting SARS-CoV-2 could provide immediate protection after SARS-CoV-2 infection, especially for the most vulnerable populations. In this work, we comprehensively characterize the breadth and efficacy of SARS-CoV-2 RBD-targeting fully human monoclonal antibody (mAb) MW3321. MW3321 retains full neutralization activity to all tested 12 variants that have arisen in the human population, which are assigned as VOC (Variants of Concern) and VOI (Variants of Interest) due to their impacts on public health. Escape mutation experiments using replicating SARS-CoV-2 pseudovirus show that escape mutants were not generated until passage 6 for MW3321, which is much more resistant to escape mutation compared with another clinical staged SARS-CoV-2 neutralizing mAb MW3311. MW3321 could effectively reduce viral burden in hACE2-transgenic mice challenged with either wild-type or Delta SARS-CoV-2 strains through viral neutralization and Fc-mediated effector functions. Moreover, MW3321 exhibits a typical hIgG1 pharmacokinetic and safety profile in cynomolgus monkeys. These data support the development of MW3321 as a monotherapy or cocktail against SARS-CoV-2-related diseases.

How Rice Fights Pandemics: Nature-Crop-Human Interactions Shaped COVID-19 Outcomes.

Wealthy nations led health preparedness rankings in 2019, yet many poor nations controlled COVID-19 better. We argue that a history of rice farming explains why some societies did better. We outline how traditional rice farming led to tight social norms and low-mobility social networks. These social structures helped coordinate societies against COVID-19. Study 1 compares rice- and wheat-farming prefectures within China. Comparing within China allows for controlled comparisons of regions with the same national government, language family, and other potential confounds. Study 2 tests whether the findings generalize to cultures globally. The data show rice-farming nations have tighter social norms and less-mobile relationships, which predict better COVID outcomes. Rice-farming nations suffered just 3% of the COVID deaths of nonrice nations. These findings suggest that long-run cultural differences influence how rice societies-with over 50% of the world's population-controlled COVID-19. The culture was critical, yet the preparedness rankings mostly ignored it.

Impact of reduced anthropogenic emissions on chemical characteristics of urban aerosol by individual particle analysis.

A single particle aerosol mass spectrometer was deployed in a heavily polluted area of China during a coronavirus lockdown to explore the impact of reduced anthropogenic emissions on the chemical composition, size distributions, mixing state, and secondary formation of urban aerosols. Ten particle groups were identified using an adaptive resonance network algorithm. Increased atmospheric oxidation during the lockdown period (LP) resulted in a 42.2%-54% increase in the major NaK-SN particle fraction relative to the normal period (NP). In contrast, EC-aged particles decreased from 31.5% (NP) to 23.7% (LP), possibly due to lower emissions from motor vehicles and coal combustion. The peak particle size diameter increased from 440 nm during the NP to 500 nm during LP due to secondary particle formation. High proportions of mixed 62NO3- indicate extensive particle aging. Correlations between secondary organic (43C2H3O+, oxalate) and secondary inorganic species (62NO3-, 97HSO4- and 18NH4+) versus oxidants (Ox = O3 + NO2) and relative humidity (RH) indicate that increased atmospheric oxidation promoted the generation of secondary species, while the effects of RH were more complex. Differences between the NP and LP show that reductions in primary emissions had a remarkable impact on the aerosol particles. This study provides new insights into the effects of pollution emissions on atmospheric reactions and the specific aerosol types in urban regions.