SARS-Cov-2 Spike-S1 Antigen Test Strip with High Sensitivity Endowed by High-Affinity Antibodies and Brightly Fluorescent QDs/Silica Nanospheres.

The extensive research into developing novel strategies for detecting respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in clinical specimens, especially the sensitive point-of-care testing method, is still urgently needed to reach rapid screening of viral infections. Herein, a new lateral flow immunoassay (LFIA) platform was reported for the detection of SARS-CoV-2 spike-S1 protein antigens, in which four sensitive and specific SARS-CoV-2 mouse monoclonal antibodies (MmAbs) were tailored by using quantum dot (QD)-loaded dendritic mesoporous silica nanoparticles modified further for achieving the -COOH group surface coating (named Q/S-COOH nanospheres). Importantly, compact QD adsorption was achieved in mesoporous channels of silica nanoparticles on account of highly accessible central-radial pores and electrostatic interactions, leading to significant signal amplification. As such, a limit of detection for SARS-CoV-2 spike-S1 testing was found to be 0.03 ng/mL, which is lower compared with those of AuNPs-LFIA (traditional colloidal gold nanoparticles, Au NPs) and enzyme-linked immunosorbent assay methods. These results show that optimizing the affinity of antibody and the intensity of fluorescent nanospheres simultaneously is of great significance to improve the sensitivity of LFIA.

The effect of an information intervention on the career commitment of medical students: evidence from a randomized experiment.

Introduction: The needs-based shortage of healthcare workers is severe worldwide and it would be exacerbated if many medical students switch to other careers after graduation. Maintaining and improving the career commitment of medical students, which could be a feasible, effective, and scalable way to reduce the attrition rate, is essential in medical education. We designed a randomized experiment to test whether an information intervention based on role modeling could enhance medical students' career commitment. Methods: In the randomized experiment, the sample (N = 36,482) was divided into the treatment group (N = 18,070) and the control group (N = 18,412). The intervention information consisted of image-text messages on Zhong Nanshan, who is an inspiring role model for he went to the frontline of COVID-19 in the most critical circumstances and received praise and affirmation from the public. Α difference-in-differences model was employed to identify the effect of the information intervention. Heterogeneous treatment effects were identified using sub-sample analyses. Results: The results showed that the information intervention statistically significantly reduced medical students' dropout intention by 2.7 percentage points (95% CI: -0.037 to -0.016, t = -4.95, p < 0.001), equivalent to 14.6% of the control group mean. This estimate indicates that the information intervention could significantly increase the career commitment of medical students. Finally, male and senior students were influenced more than their female and junior counterparts, which can be explained by their relatively high dropout intention. Conclusion: Role model-based information intervention improves the career commitment of medical students. The underlying behavioral model is that, when students use a role model as their reference point, they consider dropout as a substantial welfare loss. Role modeling is an effective way to improve the career commitment of medical students, especially for males and senior students.

Prosocial modelling matters: the association between parent and faculty involvement in fighting COVID-19 with medical students' career commitment.

BACKGROUND: Role models are essential in medical education, yet empirical research is relatively insufficient on the influence of prosocial modelling on medical students' career commitment. The prosocial behaviour of medical staff involved in the fight against the novel coronavirus disease 2019 (COVID-19) at the beginning of 2020 presents an opportunity to fill the research gap. We explored and compared the different associations of the two most important role models for medical students - parents and faculty- with medical students' career commitment. METHODS: The cross-sectional study was conducted with 99,559 undergraduate students majoring in clinical medicine in mainland China. Questions were asked to collect information about participants in the battle against COVID-19, medical students' determination to practice medicine after graduation, as well as students' socio-demographic characteristics. Chi-square tests and hierarchical regressions were performed to examine the associations between parent and faculty involvement and students' career commitment. RESULTS: The results showed statistically significant associations between prosocial modelling during the COVID-19 pandemic in China and students' intention to pursue medical careers. The association of faculty involvement (OR = 1.165, p < .001) with students' career commitment was greater than that of parents (OR = 0.970, p > .05). For faculty involvement, the association was stronger among male students (OR = 1.323, p < .001) and students who were already determined to be doctors (OR = 1.219, p < .001) before the pandemic. CONCLUSIONS: Our study provides new evidence on the potential roles of parents and faculty in shaping medical students' career commitment. Encouraging faculty to act as positive role models could help medical students increase their intention to become doctors.KEY MESSAGESProsocial modelling could enhance students' intention to pursue medical careers.The association of prosocial behaviour of faculty is larger than that of parents on medical students.Those who have prior medical career commitment are much more likely to persist in the medical profession, and prosocial modelling of faculty is positively associated with their medical career commitment.

Genotyping, virulence genes and drug resistance of MRSA strains isolated from skin and soft tissue infection in Tianjin

OBJECTIVE: To investigate and analyze the genotyping, virulence genes and drug-resistant genes of methicillin resistant Staphylococcus aureus (MRSA) strains isolated from skin and soft tissue infections in this area. METHODS: The skin secretions of 204 patients with skin and soft tissue infections in the Fifth Central Hospital of Tianjin between Jan. 2019 and Dec. 2020 were collected, and MRSA strains identified as non-repetitive strains were isolated. The Staphylococcal cassette chromosome mec (SCCmec) and Staphylococcal protein A gene (spa) genotyping and Panton-valentine leukocidin (PVL) gene carrying status were analyzed among the MRSA strains, and their relationship with drug resistance was analyzed. RESULTS: Totally 82 strains of S. aureus were isolated from the skin secretions of 204 patients with skin and soft tissue infections, including 44 strains of MRSA (53.66%). The most common SCCmec genotype was genotype III (accounting for 84.09%) and the most common spa genotype was genotype t030 (accounting for 84.09%). PVL genes encoding virulence factors were amplified in 5 strains (11.36%). The drug resistance rates of 44 MRSA strains to vancomycin and compound sulfamethoxazole were 0.00%, and all the strains were drug-resistant to penicillin. Different SCCmec and spa genotypes were highly resistant to erythromycin, cefazolin, clindamycin and levofloxacin, but the differences in drug resistance rates of different SCCmec genotypes to clindamycin and levofloxacin were significant (P < 0.05). The resistance rates of strains with PVL positive genes to chloramphenicol, gentamicin and tetracycline were significantly higher than those with PVL negative genes (P < 0.05). CONCLUSION: Strains carrying SCCmec III and spa t030 genotypes may be the dominant strains of MRSA in skin and soft tissue infections in this area. Spa genotypes and PVL gene have certain impact on drug resistance of MRSA, and the isolated MRSA strains are all sensitive to vancomycin and compound sulfamethoxazole, which can provide a reference for anti-MRSA treatment in this area.

Safety and Immunogenicity of a Recombinant Adenovirus Type-5-Vectored Coronavirus Disease 2019 (COVID-19) Vaccine With a Homologous Prime-Boost Regimen in Healthy Participants Aged ≥6 Years: A Randomized, Double-Blind, Placebo-Controlled, Phase 2b Trial.

BACKGROUND: We assessed the safety and immunogenicity of a recombinant adenovirus type-5 (Ad5)-vectored coronavirus disease 2019 (COVID-19) vaccine with homologous prime-boost regimens in healthy participants aged ≥6 years. METHODS: In this randomized, double-blind, placebo-controlled trial, participants received vaccine or placebo 56 days apart. Enzyme-linked immunosorbent assay (ELISA) antibodies to the receptor binding domain (RBD) and pseudovirus neutralizing antibodies were detected. Adverse events were monitored for 28 days following each vaccination. RESULTS: A total of 430 participants were enrolled in the study, with 30 participants aged 18-55 years (MID cohort), 250 aged ≥56 years (OLD cohort), and 150 aged 6-17 years (MIN cohort). Ad5-vectored COVID-19 vaccine induced significant RBD-specific ELISA antibodies that decreased with increasing age, with geometric mean titers (GMTs) of 1037.5 in the MIN cohort, 647.2 in the MID cohort, and 338.0 in the OLD cohort receiving 5 × 1010 viral particles on day 28 following boost vaccination. Pseudovirus neutralizing antibodies showed a similar pattern, with GMTs of 168.0 in the MIN cohort, 76.8 in the MID cohort, and 79.7 in the OLD cohort. A single dose in children and adolescents induced higher antibody responses than that elicited by 2 doses in adults, with GMTs of 1091.6 and 96.6 for ELISA antibody and neutralizing antibody, respectively. Homologous prime-boost vaccination was safe and tolerable. CONCLUSIONS: Ad5-vectored COVID-19 vaccine with a single dose was safe and induced robust immune responses in children and adolescents aged 6-17 years. A prime-boost regimen needs further exploration for Ad5-vectored COVID-19 vaccine.Ad5-vectored COVID-19 vaccine with a single dose was safe and tolerated, and induced robust immune responses in children and adolescents aged 6-17 years. The boosting effect on immune responses of the homologous prime-boost regime given 56 days apart was limited. CLINICAL TRIALS REGISTRATION: NCT04566770.

Still want to be a doctor? Medical student dropout in the era of COVID-19.

This research examines the intention of undergraduate medical students to withdraw from the medical profession and pursue a career in a different field upon graduation during COVID-19. We leverage the first and most comprehensive nationwide survey for medical education in China, which covered 98,668 enrolled undergraduate students from 90 out of 181 Chinese medical schools in 2020. We focus on these students' self-reported intention to leave the healthcare industry (the "dropout intention") before and after the outbreak of the epidemic. We also designed a randomized experiment to test whether and to what extent medical students dropout intention responded to an information nudge that highlighted the prosociality of health professionals in the fight against the virus. Results from a difference-in-differences model and a student fixed effect model suggest that after the onset of COVID-19, the proportion of Chinese undergraduate medical students with a dropout intention declined from 13.7% to 6.8%. Furthermore, the nudge information reduced the intent-to-drop-out probability by 0.8 additional percentage points for students in their early college years. There was large heterogeneity underneath the treatment effect. Specifically, we find that prior dropout intention and exposures to COVID-19-related information tended to mitigate the nudge effects. Data on students' actual dropout outcomes support our findings.

Twelve tips for teaching medical students online under COVID-19.

Universities worldwide are pausing in an attempt to contain COVID-19's spread. In February 2019, universities in China took the lead, cancelling all in-person classes and switching to virtual classrooms, with a wave of other institutes globally following suit. The shift to online platform poses serious challenges to medical education so that understanding best practices shared by pilot institutes may help medical educators improve teaching. Provide 12 tips to highlight strategies intended to help on-site medical classes moving completely online under the pandemic. We collected 'best practices' reports from 40 medical schools in China that were submitted to the National Centre for Health Professions Education Development. Experts' review-to-summary cycle was used to finalize the best practices in teaching medical students online that can benefit peer institutions most, under the unprecedented circumstances of the COVID-19 outbreak. The 12 tips presented offer-specific strategies to optimize teaching medical students online under COVID-19, specifically highlighting the tech-based pedagogy, counselling, motivation, and ethics, as well as the assessment and modification. Learning experiences shared by pilot medical schools and customized properly are instructive to ensure a successful transition to e-learning.

Students' initial perspectives on online learning experience in China during the COVID-19 outbreak: expanding online education for future doctors on a national scale.

BACKGROUND: During the early stage of COVID-19 outbreak in China, most medical undergraduate programs have to eventually embrace the maneuver of transferring to nearly 100% online-learning as a new routine for different curricula. And there is a lack of empirical evidence of effective medical education curriculum that has been completely implemented in an online format. This study summarizes medical students' perspectives regarding online-learning experience during the COVID-19 outbreak and presents reflection on medical education. METHODS: From February 21st to March 14th, 2020, the authors conducted survey of a nationally representative sample of undergraduate medical students from 90 medical schools in China. Participant demographics and responses were tabulated, and independent sample t-tests as well as multiple logistic regression models were used to assess the associations of demographic characteristics, prior online learning experience, and orientation with students' perspectives on the online learning experience. RESULTS: Among 118,030 medical students participated in the survey (response rate 52.4%), 99,559 provided valid data for the analysis. The sample is fairly nationally representative. 65.7% (65,389/99,559) supported great orientation and 62.1% (61,818/99,559) reported that they were satisfied with the ongoing online-learning experience. The most common problem students would encounter was the network congestion (76,277/99,559; 76.6%). Demographics, learning phases, and academic performance were associated with online-learning engagement and perceptions. Formal orientation and prior PU (perceived usefulness of online learning) were significantly positively associated with the satisfaction and evaluation of the online learning experience (p <  0.001). CONCLUSIONS: Data from this national survey indicates a relatively positive role of online learning as a formal teaching/learning approach in medical education. Considerations should be made regarding such application in aspects of students' different learning phases. We suggest that further policy interventions should be taken from technological, organizational, environmental, as well as individual aspects, to help improve the outcome of online learning for future doctors.

Association between medical students' prior experiences and perceptions of formal online education developed in response to COVID-19: a cross-sectional study in China.

OBJECTIVES: (1) Understanding the characteristics of online learning experiences of Chinese undergraduate medical students; (2) Investigating students' perceptions of ongoing online education developed in response to COVID-19 and (3) Exploring how prior online learning experiences are associated with students' perceptions. DESIGN: Students' familiarity with online learning modes and corresponding perceived usefulness (PU) according to their previous experiences were investigated using an online survey. The survey also collected data on students' perceptions through their evaluation of and satisfaction with current online learning. SETTING: In response to the educational challenges created by COVID-19, medical schools in China have adopted formal online courses for students. PARTICIPANTS: The questionnaire was sent to 225 329 students, of whom 52.38% (118 080/225 329) replied, with valid data available for 44.18% (99 559/225 329). METHODS: Pearson correlations and t-tests were used to examine the relationship between familiarity and PU. Multiple linear regression and logistic regression analyses were used to determine the impact of prior learning experiences and its interactions with gender, area, learning phase and academic performance on students' perceptions. RESULTS: Students' PU had a significant positive correlation with their familiarity with online learning modes (p<0.01). Students' evaluation of and satisfaction with their current online education were positively associated with their familiarity (ß=0.46, 95% CI 0.45 to 0.48, p<0.01; OR 1.14, 95% CI 1.13 to 1.14, p<0.01) with and PU (ß=3.11, 95% CI 2.92 to 3.30, p<0.01; OR 2.55, 95% CI 2.37 to 2.75, p<0.01) of online learning. Moreover, the higher the students' learning phases, the lower the associations between PU and students' evaluation of and satisfaction with ongoing online education. CONCLUSIONS: Medical students in China have experiences with various online learning modes. Prior learning experiences are positively associated with students' evaluation of and satisfaction with current online education. Higher learning phases, in which clinical practices are crucial, and high academic performance led to lower evaluation and satisfaction scores.