ABSTRACT
Since 2020, the COVID-19 pandemic severely disrupted regular off-line business activities. This unprecedented situation inspires the valuable research on facilitating off-line business under pandemics. In this article, we conceptualized the problem as travel management in pandemic (TMiP) and analyzed it from the technological perspective. Enabling travel in a pandemic not only needs a health certificate to prove that the traveler is safe but also entry/exit permissions from both the origin and the destination regions, determined by the local situation and measures. Thus, TMiP is related to technical, social, economic, and administrative factors. By conducting a review on the literature covering the health certificate technology, its adoption in practice, and the exchange system technology published during the COVID-19 pandemic, we learned about their usefulness and limitations in TMiP. Second, we analyzed the review outcomes to infer the six distinctive technical challenges of TMiP. Third, we analyzed the feasibility of referential solutions to these challenges and showed their applicability and limitations. Finally, we offered the perspectives on new TMiP solutions and concluded that they rely on adapting existing solutions, creating new ones, and integrating all of them. We also presented future research directions in a holistic view of TMiP technical solutions. Overall, the findings of the study will stimulate more research on a more coordinated, comprehensive, and intelligent TMiP solution. We also hope this article can help practitioners to restart economies in a pandemic.
ABSTRACT
A reliable and reproducible model in vitro for swine enteric coronaviruses infection would be intestinal models that support virus replication and can be long-term cultured and manipulated experimentally. Here, we designed a robust long-term culture system for porcine intestinal organoids from the intestinal crypt or single LGR5+ stem cell by combining previously defined insights into the growth requirements of the intestinal epithelium of humans. We showed that long-term cultured swine intestinal organoids were expanded in vitro for more than 6 months and maintained the potential to differentiate into different types of cells. These organoids were successfully infected with porcine enteric coronavirus, including porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), and were capable of supporting virus replication and progeny release. RNA-seq analysis showed robust induction of transcripts associated with antiviral signaling in response to enteric coronavirus infection, including hundreds of interferon-stimulated genes and cytokines. Moreover, gene set enrichment analysis indicated that PEDV infection could suppress the immune response in organoids. This 3D intestinal organoid model offers a long-term, renewable resource for investigating porcine intestinal infections with various pathogens.