Design of online formative assessment of nursing humanities curriculum during the COVID-19 pandemic: A teaching practice research.

BACKGROUND: Under the digital transformation trend nursing education, online formative assessment (OFA) provides a new opportunity. However, the OFA of nursing humanities course lacks design and practice, and faces the challenge of enhancing effective communication between teachers and students, student participation and autonomous learning. OBJECTIVES: To enhance the reliability of OFA in nursing humanities courses and provide practical experience for online teaching in the nursing profession. DESIGN: A quantitative research approach was used. SETTING: This study was conducted in a comprehensive university in China. PARTICIPANTS: We conducted teaching practice on 185 nursing undergraduates, with 89 students in the experimental group, and 96 students in the control group. METHODS: In the 2020-2021 multicultural nursing course, student learning outcomes and questionnaires were analyzed through the online learning tool Superstar Learning, student feedback and satisfaction questionnaires, and descriptive analysis and independent sample t-tests were conducted using SPSS 25.0 software. RESULTS: The OFA of students using Superstar Learning differed in learning performance and time to receive feedback from teachers between the experimental and control groups, and both groups had higher satisfaction levels. The experimental group's instructional design contained a synchronous classroom discussion module with better participation. CONCLUSIONS: During the COVID-19 pandemic, the use of online learning tools can support the implementation of OFA, build an environment where teachers and students participate together, have a positive impact on the continuous updating of teachers' teaching programs and students' learning outcomes. Simultaneous classroom discussions are expected to be an effective way to improve the reliability of OFA. Our instructional design, provides best practice suggestions for future online teaching and learning.

TUT4/7-mediated uridylation of a coronavirus subgenomic RNAs delays viral replication.

Coronaviruses are positive-strand RNA viruses with 3' polyadenylated genomes and subgenomic transcripts. The lengths of the viral poly(A) tails change during infection by mechanisms that remain poorly understood. Here, we use a splint-ligation method to measure the poly(A) tail length and poly(A) terminal uridylation and guanylation of the mouse hepatitis virus (MHV) RNAs. Upon infection of 17-CL1 cells with MHV, a member of the Betacoronavirus genus, we observe two populations of terminally uridylated viral transcripts, one with poly(A) tails ~44 nucleotides long and the other with poly(A) tails shorter than ~22 nucleotides. The mammalian terminal uridylyl-transferase 4 (TUT4) and terminal uridylyl-transferase 7 (TUT7), referred to as TUT4/7, add non-templated uracils to the 3'-end of endogenous transcripts with poly(A) tails shorter than ~30 nucleotides to trigger transcript decay. Here we find that depletion of the host TUT4/7 results in an increased replication capacity of the MHV virus. At late stages of infection, the population of uridylated subgenomic RNAs with tails shorter than ~22 nucleotides is reduced in the absence of TUT4/7 while the viral RNA load increases. Our findings indicate that TUT4/7 uridylation marks the MHV subgenomic RNAs for decay and delays viral replication.

Fighting the Pandemic with "Shields”: Successful COVID-19 Securitization and Mask Policy in Taiwan

Facemasks have been proven an effective non-pharmaceutical measure against coronavirus disease-19. Against the backdrop of global mask shortages, Taiwan distinguished herself from other countries in that Taiwan took a whole-of-nation approach to masks and mobilized the society quickly to become self-sufficient in masks. This paper argues that successful virus securitization as a threat to national security was what enabled Taiwan to effectively mobilize the private sector to carry out the state's will in ensuring adequate mask supply. Moreover, Taiwan securitized the virus more successfully than many other countries because the virus was connected to China, the nation's existing security threat.

What can we learn from the Baduanjin rehabilitation as COVID-19 treatment?: A narrative review.

AIM: To understand Baduanjin rehabilitation therapy in mild COVID-19 patients. DESIGN: A narrative review. METHODS: A literature search for COVID-19 and Baduanjin treatments was conducted on Chinese and English electronic databases: China National Knowledge Infrastructure, Wanfang Data, Embase, PubMed, Scopus, Science Direct, Ebscohost, SPORTDiscus and ProQuest. RESULTS: Twelve studies on the Baduanjin rehabilitation for COVID-19 patients have been included. We acknowledged the considerable published research and current clinical practice using Baduanjin for COVID-19 treatment in the following areas: anxiety, depression, insomnia, lung function rehabilitation, immunity and activity endurance. CONCLUSION: The use of Baduanjin as adjuvant therapy for COVID-19 patients' rehabilitation is still limited, therefore, more clinical studies are needed to confirm its efficacy.

Transcriptome and metabolome profiling unveils the mechanisms of naphthalene acetic acid in promoting cordycepin synthesis in Cordyceps militaris.

Cordycepin, an important active substance in Cordyceps militaris, possesses antiviral and other beneficial activities. In addition, it has been reported to effectively promote the comprehensive treatment of COVID-19 and thus has become a research hotspot. The addition of naphthalene acetic acid (NAA) is known to significantly improve the yield of cordycepin; however, its related molecular mechanism remains unclear. We conducted a preliminary study on C. militaris with different concentrations of NAA. We found that treatment with different concentrations of NAA inhibited the growth of C. militaris, and an increase in its concentration significantly improved the cordycepin content. In addition, we conducted a transcriptome and metabolomics association analysis on C. militaris treated with NAA to understand the relevant metabolic pathway of cordycepin synthesis under NAA treatment and elucidate the relevant regulatory network of cordycepin synthesis. Weighted gene co-expression network analysis (WGCNA), transcriptome, and metabolome association analysis revealed that genes and metabolites encoding cordycepin synthesis in the purine metabolic pathway varied significantly with the concentration of NAA. Finally, we proposed a metabolic pathway by analyzing the relationship between gene-gene and gene-metabolite regulatory networks, including the interaction of cordycepin synthesis key genes; key metabolites; purine metabolism; TCA cycle; pentose phosphate pathway; alanine, aspartate, and glutamate metabolism; and histidine metabolism. In addition, we found the ABC transporter pathway to be significantly enriched. The ABC transporters are known to transport numerous amino acids, such as L-glutamate, and participate in the amino acid metabolism that affects the synthesis of cordycepin. Altogether, multiple channels work together to double the cordycepin yield, thereby providing an important reference for the molecular network relationship between the transcription and metabolism of cordycepin synthesis.

Factors associated with postpartum depression symptoms among postpartum women in five countries during the COVID-19 pandemic: an online cross-sectional study.

BACKGROUND: This study aimed to examine factors associated with postpartum depression (PPD) symptoms during the COVID-19 pandemic among postpartum women in five countries, a subject that has not been investigated thus far. METHODS: A multi-country, cross-sectional, online survey was conducted with a convenience sample of 3,523 postpartum women in Brazil, South Korea, Taiwan, Thailand, and the United Kingdom, from July to November 2021. Sociodemographic and obstetric data, food insecurity, COVID-19 positive status, COVID-19 vaccination, infant feeding, breastfeeding belief score, and social support were investigated. PPD and social support were measured using the Edinburgh Postnatal Depression Scale and Maternal Social Support Scale, respectively. Descriptive statistics, chi-squared tests, and t-tests were used to identify associations with PPD symptoms. A binary logistic regression model was used to identify explanatory factors associated with PPD and adjusted odds ratios (OR) and 95% confidence intervals (CIs) were calculated. RESULTS: Women in Taiwan (AOR = 0.5; 95%CI 0.34, 0.73) and Thailand (AOR = 0.68; 95%CI 0.46, 0.99) had a lower risk of PPD symptoms than those in Brazil. In addition, women with planned pregnancies had a lower risk of PPD (AOR = 0.74; 95%CI 0.60, 0.91). Younger women (AOR = 1.62; 95%CI 1.05, 2.51), health problems during pregnancy, delivery, or postpartum (AOR = 1.71; 95%CI 1.42, 2.06), and no change or worse food insecurity during COVID-19 (AOR = 1.66; 95%CI 1.21, 1.27 for no change and AOR = 1.68; 95%CI 1.27, 1.23, respectively) presented a higher likelihood of having PPD. Feeding babies with expressed human milk (AOR = 1.25; 95%CI 1.03, 1.50) and/or complementary food (AOR = 1.51; 95%CI 1.17, 1.94) were associated with PPD symptoms. Women who received low (AOR = 7.74; 95%CI 5.43, 11.03) or medium support (AOR = 3.25; 95%CI 2.71, 3.88) had higher likelihoods of PPD. CONCLUSION: PPD symptoms during the pandemic were high in young women, particularly Brazilian women, with health problems in the puerperal pregnancy cycle who fed their babies expressed breast milk and/or complementary food. Low social support also impacted PPD symptoms. This study highlights the need for the professional screening for PPD and provision of virtual or personal support.

Associations between breastfeeding intention, breastfeeding practices and post-natal depression during the COVID-19 pandemic: A multi-country cross-sectional study.

Associations between breastfeeding intention, duration and post-natal depression (PND) have been shown in pre-COVID-19 studies. However, studies during COVID-19 have not examined the associations between breastfeeding intention, breastfeeding practices, and PND in an international sample of post-natal women, taking into consideration COVID-19 related factors. This is the first study to address this gap as both PND and breastfeeding may be affected by COVID-19, and have important long-term effects on women's and infant's health. A cross-sectional internet-based survey was conducted with 3253 post-natal women from five countries: Brazil, South Korea, Taiwan, Thailand, and the United Kingdom from July to November 2021. The results showed that women who intended to breastfeed during pregnancy had lower odds of having PND than women who did not intend to. Women who had no breastfeeding intention but actually breastfed had greater odds (AOR 1.75) of having PND than women who intended to breastfeed and actually breastfed. While there was no statistical significance in expressed breast milk feeding in multivariable logistic regression models, women who had shorter duration of breastfeeding directly on breast than they planned had greater odds (AOR 1.58) of having PND than those who breastfed longer than they planned even after adjusting for covariates including COVID-19-related variables. These findings suggested the importance of working with women on their breastfeeding intention. Tailored support is required to ensure women's breastfeeding needs are met and at the same time care for maternal mental health during and beyond the pandemic.

Nurse practitioner job preference: A discrete choice experiment.

BACKGROUND: Nurse practitioners play a critical role in improving the access to care and in meeting the needs for health care. However, prior to the COVID-19 pandemic, the average turnover rate of nurse practitioners was 10 % with associated total direct cost that ranged from $85,832 to $114,919 for each episode of turnover in the United States. Little is known about the job preference of nurse practitioners and the cost savings to an organization that provides jobs with characteristics attractive to nurse practitioners. OBJECTIVE: The aim of this study was to identify the preferred job characteristics that are associated with nurse practitioners' job choices; and to determine the extent to which nurse practitioners would need to be compensated for practicing without these characteristics. DESIGN: A two-stage design using a mixed method approach. SETTING(S): The state of Georgia in the United States. PARTICIPANTS: 2757 nurse practitioners who were actively licensed were invited to participate. Of the 412 participants, 372 actively employed in Georgia were included in the analysis. METHODS: A 2-stage discrete choice experiment was designed. Stage-1 was a qualitative design using a focus group to identify nurse practitioners' preferred job characteristics. Stage-2 was a quantitative design using survey distribution and analysis. A mixed logit model was used for ranking nurse practitioners' preferred job characteristics and the extent to which they would need to be compensated. RESULTS: On average nurse practitioners were 47.4 years of age; the majority were female (90 %), white (75.3 %), and educated at the master's level (88.7 %). Participants did not value teams that were not very cohesive (ß = -1.50); administration that was not very responsive and supportive (ß = -1.04); being supervised by a physician (ß = -0.58); not having their own panel of patients (ß = -0.42); and not billing under their own National Provider Identifier (ß = -0.18). Participants would need an increase in annual income of USD$21,780 for practicing in a not very cohesive team; USD$15,280 for practicing with a not very responsive administration; and USD$21,450 for being supervised by a physician. CONCLUSIONS: A cohesive, responsive, and supportive working environment and being able to practice independently are important characteristics for nurse practitioners when choosing a job. Healthcare managers should provide a workplace culture that reflects these preferred job characteristics to attract and retain nurse practitioners. Policymakers should consider reforming the scope of practice legislation to promote the independent practice of nurse practitioners.

The Impact of the COVID-19 Pandemic on Tuberculosis Case Notification and Treatment Outcomes in Eswatini.

Objectives: We investigated the impact of COVID-19 on tuberculosis (TB) case notification and treatment outcomes in Eswatini. Methods: A comparative retrospective cohort study was conducted using TB data from eight facilities. An interrupted time series analysis, using segmented Poisson regression was done to assess the impact of COVID-19 on TB case notification comparing period before (December 2018-February 2020, n = 1,560) and during the pandemic (March 2020-May 2021, n = 840). Case notification was defined as number of TB cases registered in the TB treatment register. Treatment outcomes was result assigned to patients at the end of treatment according to WHO rules. Results: There was a significant decrease in TB case notification (IRR 0.71, 95% CI: 0.60-0.83) and a significant increase in death rate among registrants during the pandemic (21.3%) compared to pre-pandemic (10.8%, p < 0.01). Logistic regression indicated higher odds of unfavorable outcomes (death, lost-to-follow-up, and not evaluated) during the pandemic than pre-pandemic (aOR 2.91, 95% CI: 2.17-3.89). Conclusion: COVID-19 negatively impacted TB services in Eswatini. Eswatini should invest in strategies to safe-guard the health system against similar pandemics.

Lipid-mRNA nanoparticles landscape for cancer therapy.

Intracellular delivery of message RNA (mRNA) technique has ushered in a hopeful era with the successive authorization of two mRNA vaccines for the Coronavirus disease-19 (COVID-19) pandemic. A wide range of clinical studies are proceeding and will be initiated in the foreseeable future to treat and prevent cancers. However, efficient and non-toxic delivery of therapeutic mRNAs maintains the key limited step for their widespread applications in human beings. mRNA delivery systems are in urgent demand to resolve this difficulty. Recently lipid nanoparticles (LNPs) vehicles have prospered as powerful mRNA delivery tools, enabling their potential applications in malignant tumors via cancer immunotherapy and CRISPR/Cas9-based gene editing technique. This review discusses formulation components of mRNA-LNPs, summarizes the latest findings of mRNA cancer therapy, highlights challenges, and offers directions for more effective nanotherapeutics for cancer patients.

Fighting the Pandemic with “Shields”: Successful COVID-19 Securitization and Mask Policy in Taiwan

Facemasks have been proven an effective non-pharmaceutical measure against coronavirus disease-19. Against the backdrop of global mask shortages, Taiwan distinguished herself from other countries in that Taiwan took a whole-of-nation approach to masks and mobilized the society quickly to become self-sufficient in masks. This paper argues that successful virus securitization as a threat to national security was what enabled Taiwan to effectively mobilize the private sector to carry out the state’s will in ensuring adequate mask supply. Moreover, Taiwan securitized the virus more successfully than many other countries because the virus was connected to China, the nation’s existing security threat. [ FROM AUTHOR]

COVID-19 and the duration of operating room procedures in Ontario: a population-based retrospective study.

BACKGROUND: Studies have estimated that a large backlog of procedures was generated by emergency measures implemented in Ontario, Canada, at the onset of the COVID-19 pandemic, when nonessential and scheduled procedures were postponed. Understanding the impact of the COVID-19 pandemic on the time needed to perform a procedure may help to determine the resources needed to tackle the substantial backlog caused by the deferral of cases. The purpose of this study was to examine the duration of operating room (OR) procedures before and after the onset of the COVID-19 pandemic to inform planning around changes in required resources. METHODS: A population-based, retrospective cohort study was conducted using Ontario Health Insurance Plan claims data and other administrative health care data from Apr. 1, 2019, to Sept. 30, 2020. Statistical analysis was conducted using multivariate regression, with procedure duration as the outcome variable. RESULTS: Results showed that the average duration of nonelective procedures increased by 34 minutes during the COVID-19 period and by 19 minutes after the resumption of scheduled procedures. Controlling for physician, patient and hospital characteristics, and the procedure code submitted, procedure duration increased by 12 minutes in the nonelective COVID-19 period and by 5 minutes when scheduled procedures resumed, compared with the pre-COVID-19 period. CONCLUSION: Procedures may take longer in the COVID-19 period. This will affect wait times, which had already increased because of the deferral of procedures at the beginning of the pandemic, and will have an impact on Ontario's ability to provide patients with timely care.

Impact of the COVID-19 pandemic upon self-reported physician burnout in Ontario, Canada: evidence from a repeated cross-sectional survey.

OBJECTIVES: To estimate the impact of the SARS-CoV-2 (COVID-19) pandemic on levels of burnout among physicians in Ontario, Canada, and to understand physician perceptions of the contributors and solutions to burnout. DESIGN: Repeated cross-sectional survey. SETTING: Active and retired physicians, residents and medical students in Canada's largest province were invited to participate in an online survey via an email newsletter. PARTICIPANTS: In the first survey wave (March 2020), 1400 members responded (representing 76.3% of those who could be confirmed to have received the survey and 3.1% of total membership). In the second wave (March 2021), 2638 responded (75.9% of confirmed survey recipients and 5.8% of membership). KEY OUTCOME MEASURE: Level of burnout was assessed using a validated, single-item, self-defined burnout measure where options ranged from 1 (no symptoms of burnout) to 5 (completely burned out). RESULTS: The overall rate of high levels of burnout (self-reported levels 4-5) increased from 28.0% in 2020 (99% CI: 24.3% to 31.7%) to 34.7% in 2021 (99% CI: 31.8% to 37.7%), a 1-year increase of 6.8 percentage points (p<0.01). After a full year of practising during the COVID-19 pandemic, respondents ranked 'patient expectations/patient accountability', 'reporting and administrative obligations' and 'practice environment' as the three factors that contributed most to burnout. Respondents ranked 'streamline and reduce required documentation/administrative work', 'provide fair compensation' and 'improve work-life balance' as the three most important solutions. CONCLUSIONS: During the first 12 months of the COVID-19 pandemic in Ontario, prevalence of high levels of burnout had significantly increased. The contributors and solutions ranked highest by physicians were system-level or organisational in nature.

The characteristics and practice proficiency of nurse practitioners who care for older adults.

Roughly 54 million Americans are 65 years of age or older. Given the number of comorbid diseases reported in older adults, healthcare tailored to the specific needs of this population is imperative. Nurse practitioners (NPs) are uniquely positioned to provide care to older adults; yet little is known about the geriatric-oriented NP workforce. In this study, four professional organizations distributed a survey link to their members who were queried on their demographic, employment, and practice characteristics; one organization's members responded to a previous survey, providing two time points for comparison. Compared with 2016 respondents, there was minimal growth in diversity, fewer who practice in suburban or rural areas, and restrictions on clinical education related to the ongoing pandemic. The findings from this study should alert policymakers of the need to address the development of an adequate workforce of clinicians who specialize in geriatrics.

Amine-Functionalized Quantum Dots as a Universal Fluorescent Nanoprobe for a One-Step Loop-Mediated Isothermal Amplification Assay with Single-Copy Sensitivity.

Loop-mediated isothermal amplification (LAMP) has received considerable attention for decentralized (point-of-care and on-site) nucleic acid testing in view of its simple temperature control (60-65 °C) and short assay time (15-60 min). There remains a challenge in its wide adoption and acceptance due to the limitations of the existing amplification result reporter probes, e.g., photobleaching of organic fluorophore and reduced sensitivity of the pH-sensitive colorimetric dye. Herein, we demonstrate CdSeS/ZnS quantum dots (semiconductor fluorescent nanocrystals with superior photostability than organic fluorophore) with surface modification of cysteamine (amine-QDs) as a new reporter probe for LAMP that enabled single-copy sensitivity (limit of detection of 83 zM; 20 µL reaction volume). For a negative LAMP sample (absence of target sequence), positively charged amine-QDs remained dispersed due to interparticle electrostatic repulsion. While for a positive LAMP sample (presence of target sequence), amine-QDs became precipitated. The characterization data showed that amine-QDs were embedded in magnesium pyrophosphate crystals (generated during positive LAMP), thus leading to their coprecipitation. This amine-QD-based one-step LAMP assay advances the field of QD-based nucleic acid amplification assays in two aspects: (1) compatibility─one-step amplification and detection (versus separation of amplification and detection steps); and (2) universality─the same amine-QDs for different target sequences (versus different oligonucleotide-modified QDs for different target sequences).

Family function and life satisfaction of postgraduate medical students during the COVID-19 pandemic: the mediating role of meaning in life and depression.

Recent studies have documented life satisfaction of people have changed during the COVID-19 pandemic. However, it is unknown about the influential factors and mechanisms of life satisfaction of postgraduate medical students during the COVID-19 pandemic. There is a strong link among life satisfaction and individual quality of life and achievement, so it is important to explore the influence mechanism of life satisfaction of postgraduate medical students and explore ways to improve life satisfaction for the development of postgraduate medical students. The current study was based on the Circumplex Model of Marital and Family System, The Theory of Family Functioning, The Meaning Maintenance Model, The Theory of Personal Meaning and Existential Theory to construct theoretical framework and examine whether meaning in life and depression would mediate the link between family function and postgraduate medical students' life satisfaction. By convenient sampling method, a total of 900 postgraduate medical students (Mage = 27.01 years, SD = 3.33) completed questionnaires including Family APGAR Scale, Chinese Version of Meaning In Life Questionnaire, Patient Health Questionnaire, and Satisfaction With Life Scale. In this study, SPSS 25.0 was used for correlation analysis, regression analysis and common method bias test, and AMOS 23.0 was used for structural equation modeling analysis. The results showed that (a) family function could predict life satisfaction of postgraduate medical students significantly; (b) both meaning in life and depression mediated the association between family function and life satisfaction in a parallel manner; (c) meaning in life and depression sequentially mediated the link between family function and life satisfaction of postgraduate medical students. The study illuminates the role of meaning in life and depression in improving life satisfaction and implies that it is necessary to focus on the changes of life satisfaction of postgraduate medical students during the COVID-19 pandemic, and medical educator can improve the sense of meaning in life of postgraduate medical students through improving their family function, further decreasing the risk of depression, finally improving their life satisfaction.

Impact of COVID-19 on breastfeeding intention and behaviour among postpartum women in five countries.

BACKGROUND: Studies regarding the impact of COVID-19 on breastfeeding have mostly used single- country samples or a qualitative design. AIM: The objective of this study was to examine breastfeeding intention during pregnancy and breastfeeding behaviour among postpartum women in five countries during the COVID-19 pandemic and the associated factors. METHODS: An online questionnaire survey was conducted in Thailand, the United Kingdom, South Korea, Taiwan, and Brazil from July through November 2021. The study participants included 3253 mothers within six months of birth. FINDINGS: About 90% of participants intended to breastfeed during pregnancy and 85.7% reported breastfeeding in the past 24 h. More than half reported their breastfeeding duration being as planned or longer despite COVID-19. Multivariate logistic regression models showed that being multiparous, ever tested COVID-19 positive, and having positive breastfeeding beliefs were associated with increased odds for intention to breastfeed during pregnancy. Lower maternal educational level, being primiparous, ever tested COVID-19 positive, and experiencing food insecurity were associated with decreased odds for breastfeeding duration being as planned or longer. Vaginal birth, currently working or on maternity leave, breastfeeding beliefs, breastfeeding support from spouse/partner/friend/relative, online support groups, and in-person or telephone contact with healthcare professionals were associated with increased odds for breastfeeding duration being as planned or longer. CONCLUSION: Breastfeeding intention and behaviour remained high during the COVID-19 pandemic. Online support groups and telephone contact with health professionals were effective during the pandemic.

Antigenic Cross-Reactivity Between SARS-CoV-2 S1-RBD and Its Receptor ACE2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging virus responsible for the ongoing COVID-19 pandemic. SARS-CoV-2 binds to the human cell receptor angiotensin-converting enzyme 2 (ACE2) through its receptor-binding domain in the S1 subunit of the spike protein (S1-RBD). The serum levels of autoantibodies against ACE2 are significantly higher in patients with COVID-19 than in controls and are associated with disease severity. However, the mechanisms through which these anti-ACE2 antibodies are induced during SARS-CoV-2 infection are unclear. In this study, we confirmed the increase in antibodies against ACE2 in patients with COVID-19 and found a positive correlation between the amounts of antibodies against ACE2 and S1-RBD. Moreover, antibody binding to ACE2 was significantly decreased in the sera of some COVID-19 patients after preadsorption of the sera with S1-RBD, which indicated that antibodies against S1-RBD can cross-react with ACE2. To confirm this possibility, two monoclonal antibodies (mAbs 127 and 150) which could bind to both S1-RBD and ACE2 were isolated from S1-RBD-immunized mice. Measurement of the binding affinities by Biacore showed these two mAbs bind to ACE2 much weaker than binding to S1-RBD. Epitope mapping using synthetic overlapping peptides and hydrogen deuterium exchange mass spectrometry (HDX-MS) revealed that the amino acid residues P463, F464, E465, R466, D467 and E471 of S1-RBD are critical for the recognition by mAbs 127 and 150. In addition, Western blotting analysis showed that these mAbs could recognize ACE2 only in native but not denatured form, indicating the ACE2 epitopes recognized by these mAbs were conformation-dependent. The protein-protein interaction between ACE2 and the higher affinity mAb 127 was analyzed by HDX-MS and visualized by negative-stain transmission electron microscopy imaging combined with antigen-antibody docking. Together, our results suggest that ACE2-cross-reactive anti-S1-RBD antibodies can be induced during SARS-CoV-2 infection due to potential antigenic cross-reactivity between S1-RBD and its receptor ACE2.