Saliva-based detection of SARS-CoV-2: a bibliometric analysis of global research.

Saliva has emerged as a promising noninvasive biofluid for the diagnosis of oral and systemic diseases, including viral infections. During the coronavirus disease 2019 (COVID-19) pandemic, a growing number of studies focused on saliva-based detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Taking advantage of the WoS core collection (WoSCC) and CiteSpace, we retrieved 1021 articles related to saliva-based detection of SARS-CoV-2 and conducted a comprehensive bibliometric analysis. We analyzed countries, institutions, authors, cited authors, and cited journals to summarize their contribution and influence and analyzed keywords to explore research hotspots and trends. From 2020 to 2021, research focused on viral transmission via saliva and verification of saliva as a reliable specimen, whereas from 2021 to the present, the focus of research has switched to saliva-based biosensors for SARS-CoV-2 detection. By far, saliva has been verified as a reliable specimen for SARS-CoV-2 detection, although a standardized procedure for saliva sampling and processing is needed. Studies on saliva-based detection of SARS-CoV-2 will promote the development of saliva-based diagnostics and biosensors for viral detection. Collectively, our findings could provide valuable information to help scientists perceive the basic knowledge landscapes on saliva-based detection of SARS-CoV-2, the past and current research hotspots, and future opportunities.

College Students' Entrepreneurial Intention and Alertness in the Context of the COVID-19 Pandemic

This research aims to explore how the COVID-19 pandemic has affected college students' entrepreneurial intention (EI), as well as whether the well-studied link between entrepreneurial alertness (EA) and EI is involved. Data were collected from 612 respondents, and using the stepwise regression method we examined the moderating role of college students' perceived risk of COVID-19 on the connection between EA and EI. The results show that students' perceived risk of COVID-19 reduces their EI. Furthermore, the perceived risk of COVID-19 attenuates the relationship between EA and EI. Specifically, those who perceived a greater risk tended to show lower EI. This article contributes to a better understanding of how the relationship between EA and EI has changed during the pandemic.

Source apportionment of PM2.5 and sulfate formation during the COVID-19 lockdown in a coastal city of southeast China.

Revealing the changes in chemical compositions and sources of PM2.5 is important for understanding aerosol chemistry and emission control strategies. High time-resolved characterization of water-soluble inorganic ions, elements, organic carbon (OC), and elemental carbon (EC) in PM2.5 was conducted in a coastal city of southeast China during the COVID-19 pandemic. The results showed that the average concentration of PM2.5 during the city lockdown (CLD) decreased from 46.2 µg m-3 to 24.4 µg m-3, lower than the same period in 2019 (PM2.5: 37.1 µg m-3). Concentrations of other air pollutants, such as SO2, NO2, PM10, OC, EC, and BC, were also decreased by 27.3%-67.8% during the CLD, whereas O3 increased by 28.1%. Although SO2 decreased from 4.94 µg m-3to 1.59 µg m-3 during the CLD, the concentration of SO42- (6.63 µg m-3) was comparable to that (5.47 µg m-3) during the non-lockdown period, which were attributed to the increase (16.0%) of sulfate oxidation rate (SOR). Ox (O3+NO2) was positively correlated with SO42-, suggesting the impacts of photochemical oxidation. A good correlation (R2 = 0.557) of SO42- and Fe and Mn was found, indicating the transition-metal ion catalyzed oxidation. Based on positive matrix factorization (PMF) analysis, the contribution of secondary formation to PM2.5 increased during the epidemic period, consisting with the increase of secondary organic carbon (SOC), while other primary sources including traffic, dust, and industry significantly decreased by 9%, 8.5%, and 8%, respectively. This study highlighted the comprehensive and nonlinear response of chemical compositions and formation mechanisms of PM2.5 to anthropogenic emissions control under relatively clean conditions.

Synchronous distance education vs traditional education for health science students: A systematic review and meta-analysis.

CONTEXT: Synchronous distance education (SDE) has been widely used for health science students in recent years. This study examined the effectiveness and acceptance of SDE compared with traditional education for health science students and explored the potential moderators that could impact the pooled results. METHODS: A systematic review and meta-analysis was conducted of randomised controlled trials (RCTs) from January 2000 to March 2020 searched on nine electronic databases, including Web of Science, PubMed, Cochrane Library, Scopus, EMBASE, CINAHL, ERIC, PsycINFO, and ProQuest Dissertations and Theses. The outcomes measured were knowledge, skills with objective assessments and overall satisfaction with subjective evaluations. The pooled results were calculated using random-model effects, and moderators were explored through meta-regression. RESULTS: A total of seven RCTs with 594 participants were included. At the post-test level, the pooled effect size of knowledge acquisitions (SMD 0.12, 95% CI -0.07-0.32) showed insignificant difference between the SDE and traditional education groups (P = .207), with low heterogeneity (I2  = 17.6%). Subgroup analyses observed no factors that significantly impacted the pooled results of knowledge acquisition at the post-test levels (P for interaction > 0.05). Knowledge gains from pretest to post-test in SDE groups also did not differ significantly between groups (SMD 0.15, 95% CI -0.22-0.53; P = .428). The pooled effect size of skills (SMD 0.02, 95% CI -0.24-0.28; P = .735) was similarly insignificant. The pooled effect size of overall satisfaction (SMD 0.60, 95% CI 0.38-0.83; P < .001) significantly favoured SDE over traditional education. Incorporating two-group studies without randomisations did not significantly change the overall results of knowledge acquisition at the post-test level (SMD -0.002, 95% CI -0.11-0.10; P = .994), with moderate heterogeneity (I2  = 61.9%). CONCLUSIONS: Synchronous distance education was not significantly different from traditional education in effectiveness and had higher satisfaction ratings. Our findings might provide indications for adoptions of online remote education in health science education centres.