CRISPR Cas12a-enabled biosensors coupled with commercial pregnancy test strips for the visible point-of-care testing of SARS-CoV-2.

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has promoted the development of nucleic acid diagnosis technology. Several platforms with isothermal amplification methods have achieved sensitive and specific detection of SARS-CoV-2. However, they still suffer from complicated operations, delicate instruments, and unintuitive signal output modes. Here, a system consisting of CRISPR Cas12a-based biosensors and commercial pregnancy test strips (CRISPR-PTS) was established for the point-of-care testing of SARS-CoV-2. The target viral nucleic acids were finally reflected on the test strips through four steps, namely sample pretreatment, RT-RAA amplification, CRISPR Cas12a reaction, and separation-free hCG detection. This CRISPR-PTS assay possessed an outstanding sensitivity of as low as 1 copy per µL for SARS-CoV-2 detection and showed an excellent specificity in distinguishing the SARS-CoV-2 pseudovirus as well as other SARS-like viral clinical samples. In addition, the CRISPR-PTS assay performed well in practical applications, with 96.3% agreement versus RT-qPCR in spiked samples. With the advantages of low reagent cost, simple operation procedure, and visible signal output, CRISPR-PTS assay was expected to provide a strong supplement in the prevention and early diagnosis of infectious diseases in resource-limited situations.

Inactivated vaccine-elicited potent antibodies can broadly neutralize SARS-CoV-2 circulating variants.

A full understanding of the inactivated COVID-19 vaccine-mediated antibody responses to SARS-CoV-2 circulating variants will inform vaccine effectiveness and vaccination development strategies. Here, we offer insights into the inactivated vaccine-induced antibody responses after prime-boost vaccination at both the polyclonal and monoclonal levels. We characterized the VDJ sequence of 118 monoclonal antibodies (mAbs) and found that 20 neutralizing mAbs showed varied potency and breadth against a range of variants including XBB.1.5, BQ.1.1, and BN.1. Bispecific antibodies (bsAbs) based on nonoverlapping mAbs exhibited enhanced neutralizing potency and breadth against the most antibody-evasive strains, such as XBB.1.5, BQ.1.1, and BN.1. The passive transfer of mAbs or their bsAb effectively protected female hACE2 transgenic mice from challenge with an infectious Delta or Omicron BA.2 variant. The neutralization mechanisms of these antibodies were determined by structural characterization. Overall, a broad spectrum of potent and distinct neutralizing antibodies can be induced in individuals immunized with the SARS-CoV-2 inactivated vaccine BBIBP-CorV, suggesting the application potential of inactivated vaccines and these antibodies for preventing infection by SARS-CoV-2 circulating variants.

Random Regret Minimization Model of Carpool Travel Choice for Urban Residents Considering Perceived Heterogeneity and Psychological Distance 考虑感知异质性和心理距离的随机后悔最小化城市居民合乘出行选择模型

Carpooling is a sustainable, economical, and environmentally friendly solution to reduce air pollution and ease traffic congestion in urban areas. However, existing regret theories lack consideration of the heterogeneity of attribute perception in different ways and the psychological factors that affect regret, so they cannot accurately portray urban residents' carpool travel decisions and cannot provide a correct explanation of the actual carpool choice behavior. In this paper, based on the analysis of classical random regret minimization models and random regret minimization models considering heterogeneity, the concept of psychological distance is introduced to address shortcomings of the existing models and construct an improved random regret minimization model considering heterogeneity and psychological distance. The results show that the fit and explanatory effect of the improved model proposed in this paper is better than that of the other two models. The psychological distance of travel residents during the Corona Virus Disease 2019 (COVID-19) affects the anticipated regret value and the willingness to carpool. The model can better describe the carpool travel choice mechanism of travelers and effectively explain the carpool travel choice behavior of travelers.

Random Regret Minimization Model of Carpool Travel Choice for Urban Residents Considering Perceived Heterogeneity and Psychological Distance.

Carpooling is a sustainable, economical, and environmentally friendly solution to reduce air pollution and ease traffic congestion in urban areas. However, existing regret theories lack consideration of the heterogeneity of attribute perception in different ways and the psychological factors that affect regret, so they cannot accurately portray urban residents' carpool travel decisions and cannot provide a correct explanation of the actual carpool choice behavior. In this paper, based on the analysis of classical random regret minimization models and random regret minimization models considering heterogeneity, the concept of psychological distance is introduced to address shortcomings of the existing models and construct an improved random regret minimization model considering heterogeneity and psychological distance. The results show that the fit and explanatory effect of the improved model proposed in this paper is better than that of the other two models. The psychological distance of travel residents during the Corona Virus Disease 2019 (COVID-19) affects the anticipated regret value and the willingness to carpool. The model can better describe the carpool travel choice mechanism of travelers and effectively explain the carpool travel choice behavior of travelers.

A new perspective on the potential application of RIPK1 in the treatment of sepsis.

RIPK1 is a global cellular sensor that can determine the survival of cells. Generally, RIPK1 can induce cell apoptosis and necroptosis through TNF, Fas and lipopolysaccharide stimulation, while its scaffold function can sense the fluctuation of cellular energy and promote cell survival. Sepsis is a nonspecific disease that seriously threatens human health. There is some dispute in the literature about the role of RIPK1 in sepsis. In this review, the authors attempt to comprehensively discuss the differential results for RIPK1 in sepsis by summarizing the underlying molecular mechanism and putting forward a tentative idea as to whether RIPK1 can serve as a biomarker for the monitoring of treatment and progression in sepsis.

Sepsis is a syndrome that poses a serious threat to human life and health and is classified as a medical emergency by the WHO. RIPK1 can regulate the onset of apoptosis and necrosis in several ways and is known as a sensor of cell survival status. A series of clinical trials of RIPK1 drugs has been conducted this year and have demonstrated promising efficacy in inflammatory diseases, in particular. In this paper, the authors summarize recent studies on the function and mechanism of RIPK1 in sepsis and combine them with the progress in RIPK1 drug development to provide information for the study of RIPK1 in sepsis.

Infection with wild-type SARS-CoV-2 elicits broadly neutralizing and protective antibodies against omicron subvariants.

The omicron variants of SARS-CoV-2 have substantial ability to escape infection- and vaccine-elicited antibody immunity. Here, we investigated the extent of such escape in nine convalescent patients infected with the wild-type SARS-CoV-2 during the first wave of the pandemic. Among the total of 476 monoclonal antibodies (mAbs) isolated from peripheral memory B cells, we identified seven mAbs with broad neutralizing activity to all variants tested, including various omicron subvariants. Biochemical and structural analysis indicated the majority of these mAbs bound to the receptor-binding domain, mimicked the receptor ACE2 and were able to accommodate or inadvertently improve recognition of omicron substitutions. Passive delivery of representative antibodies protected K18-hACE2 mice from infection with omicron and beta SARS-CoV-2. A deeper understanding of how the memory B cells that produce these antibodies could be selectively boosted or recalled can augment antibody immunity against SARS-CoV-2 variants.

Evolution of Immune Evasion and Host Range Expansion by the SARS-CoV-2 B.1.1.529 (Omicron) Variant.

Recently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant B.1.1.529 (Omicron) has rapidly become the dominant strain, with an unprecedented number of mutations within its spike gene. However, it remains unknown whether these variants have alterations in their entry efficiency, host tropism, and sensitivity to neutralizing antibodies and entry inhibitors. In this study, we found that Omicron spike has evolved to escape neutralization by three-dose inactivated-vaccine-elicited immunity but remains sensitive to an angiotensin-converting enzyme 2 (ACE2) decoy receptor. Moreover, Omicron spike could use human ACE2 with a slightly increased efficiency while gaining a significantly increased binding affinity for a mouse ACE2 ortholog, which exhibits limited binding with wild-type (WT) spike. Furthermore, Omicron could infect wild-type C57BL/6 mice and cause histopathological changes in the lungs. Collectively, our results reveal that evasion of neutralization by vaccine-elicited antibodies and enhanced human and mouse ACE2 receptor engagement may contribute to the expanded host range and rapid spread of the Omicron variant. IMPORTANCE The recently emerged SARS-CoV-2 Omicron variant with numerous mutations in the spike protein has rapidly become the dominant strain, thereby raising concerns about the effectiveness of vaccines. Here, we found that the Omicron variant exhibits a reduced sensitivity to serum neutralizing activity induced by a three-dose inactivated vaccine but remains sensitive to entry inhibitors or an ACE2-Ig decoy receptor. Compared with the ancestor strain isolated in early 2020, the spike protein of Omicron utilizes the human ACE2 receptor with enhanced efficiency while gaining the ability to utilize mouse ACE2 for cell entry. Moreover, Omicron could infect wild-type mice and cause pathological changes in the lungs. These results reveal that antibody evasion, enhanced human ACE2 utilization, and an expanded host range may contribute to its rapid spread.

Cryoelectron microscopy structures of a human neutralizing antibody bound to MERS-CoV spike glycoprotein.

Neutralizing monoclonal antibodies (mAbs) against highly pathogenic coronaviruses represent promising candidates for clinical intervention. Here, we isolated a potent neutralizing monoclonal antibody, MERS-S41, from a yeast displayed scFv library using the S protein as a bait. To uncover the neutralization mechanism, we determined structures of MERS-S41 Fab in complex with the trimeric spike glycoprotein by cryoelectron microscopy (cryo-EM). We observed four distinct classes of the complex structure, which showed that the MERS-S41 Fab bound to the "up" receptor binding domain (RBD) with full saturation and also bound to an accessible partially lifted "down" RBD, providing a structural basis for understanding how mAbs bind to trimeric spike glycoproteins. Structure analysis of the epitope and cell surface staining assays demonstrated that virus entry is blocked predominantly by direct competition with the host receptor, dipeptidyl peptidase-4 (DPP4).

Cryoelectron microscopy structures of a human neutralizing antibody bound to MERS-CoV spike glycoprotein

Neutralizing monoclonal antibodies (mAbs) against highly pathogenic coronaviruses represent promising candidates for clinical intervention. Here, we isolated a potent neutralizing monoclonal antibody, MERS-S41, from a yeast displayed scFv library using the S protein as a bait. To uncover the neutralization mechanism, we determined structures of MERS-S41 Fab in complex with the trimeric spike glycoprotein by cryoelectron microscopy (cryo-EM). We observed four distinct classes of the complex structure, which showed that the MERS-S41 Fab bound to the “up” receptor binding domain (RBD) with full saturation and also bound to an accessible partially lifted “down” RBD, providing a structural basis for understanding how mAbs bind to trimeric spike glycoproteins. Structure analysis of the epitope and cell surface staining assays demonstrated that virus entry is blocked predominantly by direct competition with the host receptor, dipeptidyl peptidase-4 (DPP4).

Towards media systems framework in Asia Chinese and Korean media on framing the initial COVID-19 pandemic: International Journal for Mass Communication studies

Due to the relative lack of media comparison studies within Asian contexts, theoretical frameworks based in Western societies have been applied to knowledge production in the global South. Using a ‘most different’ design, this study compares the dimensions of media systems reflected in two Chinese and two Korean newspapers in their initial coverage of the COVID-19 pandemic. Content analysis showed statistically significant differences in distribution of sources, topics and valence, usage of frame types, and actors including domestic government and foreign entities held responsible between the two groups of media. Based on political implications of crisis on Chinese and Korean news content, we mainly discuss political instrumentalization and parallelism in the media in an Asian context. Finally, we open up the dimensions of media system from an Asian perspective and address the need for future research.

Recombinant angiopoietin-like protein 4 attenuates intestinal barrier structure and function injury after ischemia/reperfusion.

BACKGROUND: Intestinal barrier breakdown, a frequent complication of intestinal ischemia-reperfusion (I/R) including dysfunction and the structure changes of the intestine, is characterized by a loss of tight junction and enhanced permeability of the intestinal barrier and increased mortality. To develop effective and novel therapeutics is important for the improvement of outcome of patients with intestinal barrier deterioration. Recombinant human angiopoietin-like protein 4 (rhANGPTL4) is reported to protect the blood-brain barrier when administered exogenously, and endogenous ANGPTL4 deficiency deteriorates radiation-induced intestinal injury. AIM: To identify whether rhANGPTL4 may protect intestinal barrier breakdown induced by I/R. METHODS: Intestinal I/R injury was elicited through clamping the superior mesenteric artery for 60 min followed by 240 min reperfusion. Intestinal epithelial (Caco-2) cells and human umbilical vein endothelial cells were challenged by hypoxia/ reoxygenation to mimic I/R in vitro. RESULTS: Indicators including fluorescein isothiocyanate-conjugated dextran (4 kilodaltons; FD-4) clearance, ratio of phosphorylated myosin light chain/total myosin light chain, myosin light chain kinase and loss of zonula occludens-1, claudin-2 and VE-cadherin were significantly increased after intestinal I/R or cell hypoxia/reoxygenation. rhANGPTL4 treatment significantly reversed these indicators, which were associated with inhibiting the inflammatory and oxidative cascade, excessive activation of cellular autophagy and apoptosis and improvement of survival rate. Similar results were observed in vitro when cells were challenged by hypoxia/reoxygenation, whereas rhANGPTL4 reversed the indicators close to normal level in Caco-2 cells and human umbilical vein endothelial cells significantly. CONCLUSION: rhANGPTL4 can function as a protective agent against intestinal injury induced by intestinal I/R and improve survival via maintenance of intestinal barrier structure and functions.

Analytical Performance Evaluation of Three Commercial Rapid Nucleic Acid Assays for SARS-CoV-2.

PURPOSE: To cope with the SARS-CoV-2 epidemic, several rapid nucleic acid assays have been approved for use, but the analytical performance has not been well evaluated. In this report, two key performance parameters, analytical sensitivity (limit of detection) and reproducibility, of three approved rapid nucleic acid assays were assessed using heat-inactivated SARS-CoV-2 culture supernatants quantified by digital PCR. METHODS: The LOD (limit of detection) and reproducibility of three approved rapid nucleic acid assays using their own instruments were assessed, while the LOD and reproducibility of two assays on a 7500 Real-Time instrument were assessed at the same time. RESULTS: Using their own instruments, 100% of samples with 1150 copies/mL viral RNA could be detected by the Da An and Coyote assays, while 90% of samples could be detected by the Ustar assay; yet, for 525 copies/mL and 287.5 copies/mL viral RNA, the detection rate of the Ustar assay was higher than that of either the Da An or Coyote assays. However, the three assays did not produce statistically significant results with the three different concentrations of viral RNA (P=0.46, 0.46 and 0.46). Using a 7500 Real-Time instrument, Da An and Coyote assays did not produce statistically significant results with the 1150, 525 and 287.5 copies/mL viral RNA (P>0.99, >0.99 and >0.99). The positive and negative detection rates of the three assays in the intra- and inter-assay stages were 100% on both their own instruments and the 7500 real-time PCR instrument. CONCLUSION: Positive or strongly positive samples can be detected by the rapid nucleic acid assay, but the analytical performance should be optimized, and comprehensive evaluations are also required.

Towards media systems framework in Asia Chinese and Korean media on framing the initial COVID-19 pandemic

Due to the relative lack of media comparison studies within Asian contexts, theoretical frameworks based in Western societies have been applied to knowledge production in the global South. Using a ?most different? design, this study compares the dimensions of media systems reflected in two Chinese and two Korean newspapers in their initial coverage of the COVID-19 pandemic. Content analysis showed statistically significant differences in distribution of sources, topics and valence, usage of frame types, and actors including domestic government and foreign entities held responsible between the two groups of media. Based on political implications of crisis on Chinese and Korean news content, we mainly discuss political instrumentalization and parallelism in the media in an Asian context. Finally, we open up the dimensions of media system from an Asian perspective and address the need for future research.

Cyberbullying Involvement, Resilient Coping, and Loneliness of Adolescents During Covid-19 in Rural China.

Cyberbullying involvement can lead to internal health issues, especially mental health problems. Different coping strategies may reduce or enhance the strengths between cyberbullying experience and mental health problems. In this study, we examined the correlations between cyberbullying involvement and loneliness among a group of children and adolescents during the Covid-19 pandemic in China, focusing on investigating the protecting effect of the resilient coping strategy. The results demonstrated that 86.68% of the students were not involved in cyberbullying activities, 8.19% were victims only, 1.89% was perpetrators only, and 3.24% were both victims and perpetrators. Compared with the non-involved, the victims-only group had a significantly higher degree of reported loneliness and a lower score of resilient coping, while the differences of the other groups were not significant. Resilient coping strategy can significantly reduce loneliness and play a mediating role between cyberbullying victimization and loneliness, but such mitigating effect was relatively weak. Besides, peer relations were the primary protective factors, and age was the primary risk factor of loneliness among the controlled variables. This study can enrich current knowledge of cyberbullying involvement and the psychological health among children and adolescents, especially in the context of the pandemic.

Chloroquine differentially modulates coronary vasodilation in control and diabetic mice.

BACKGROUND AND PURPOSE: Chloroquine is a traditional medicine to treat malaria. There is increasing evidence that chloroquine not only induces phagocytosis but regulates vascular tone. Few reports investigating the effect of chloroquine on vascular responsiveness of coronary arteries have been made. In this study, we examined how chloroquine affected endothelium-dependent relaxation in coronary arteries under normal and diabetic conditions. EXPERIMENTAL APPROACH: We isolated coronary arteries from mice and examined endothelium-dependent relaxation (EDR). Human coronary endothelial cells and mouse coronary endothelial cells isolated from control and diabetic mouse (TALLYHO/Jng [TH] mice, a spontaneous type 2 diabetic mouse model) were used for the molecular biological or cytosolic NO and Ca2+ measurements. KEY RESULTS: Chloroquine inhibited endothelium-derived NO-dependent relaxation but had negligible effect on endothelium-derived hyperpolarization (EDH)-dependent relaxation in coronary arteries of control mice. Chloroquine significantly decreased NO production in control human coronary endothelial cells partly by phosphorylating eNOSThr495 (an inhibitory phosphorylation site of eNOS) and attenuating the rise of cytosolic Ca2+ concentration after stimulation. EDR was significantly inhibited in diabetic mice in comparison to control mice. Interestingly, chloroquine enhanced EDR in diabetic coronary arteries by, specifically, increasing EDH-dependent relaxation due partly to its augmenting effect on gap junction activity in diabetic mouse coronary endothelial cells. CONCLUSIONS AND IMPLICATIONS: These data indicate that chloroquine affects vascular relaxation differently under normal and diabetic conditions. Therefore, the patients' health condition such as coronary macrovascular or microvascular disease, with or without diabetes, must be taken account into the consideration when selecting chloroquine for the treatment of malaria.