No abstract

Coronavirus disease 2019 (COVID‐19) has resulted in a significantly large number of psychological consequences, including sleep health. The present study evaluated sleep patterns, sleep disturbances, and associated factors in Chinese preschoolers confined at home during the COVID‐19 outbreak. Caregivers of 1619 preschoolers (aged 4–6 years) recruited from 11 preschools in Zunyi, Guizhou province completed the Children’s Sleep Habit Questionnaire (CSHQ) between 17th and 19th February 2020. Data were compared to a sociodemographically similar sample of preschoolers (included in the 11 preschools) in 2018. Compared to the 2018 sample, the confined preschoolers demonstrated changes in sleep patterns characterized by later bedtimes and wake times, longer nocturnal and shorter nap sleep durations, comparable 24‐hr sleep duration, and fewer caregiver‐reported sleep disturbances. Moreover, behavioural practices (sleeping arrangement, reduced electronic device use, regular diet) and parenting practices (harmonious family atmosphere and increased parent‐child communication) were associated with less sleep disturbances in the confined sample. The present study provides the first description of the impact of prolonged home confinement during the COVID‐19 outbreak on sleep patterns and sleep disturbances in preschoolers, as well as highlighting the importance of the link between sleep health and family factors. Given that disrupted and insufficient sleep has been linked to immune system dysfunction, our findings also have potential implications for resilience to infection in young children during the COVID‐19 pandemic. Future studies should further explore deficient sleep as a risk factor for coronavirus infection.

17The coronavirus disease COVID-19, caused by emerging SARS-CoV-2, has posed serious 18 threats to global public health, economic and social stabilities, calling for the prompt 19 development of therapeutics and prophylactics. In this study, we firstly verified that 20 SARS-CoV-2 uses human ACE2 as a cell receptor and its spike (S) protein mediates high 21 membrane fusion activity. Comparing to that of SARS-CoV, the heptad repeat 1 (HR1) 22 sequence in the S2 fusion protein of SARS-CoV-2 possesses markedly increased α-helicity 23 and thermostability, as well as a higher binding affinity with its corresponding heptad repeat 2 24 (HR2) site. Then, we designed a HR2 sequence-based lipopeptide fusion inhibitor, termed 25 IPB02, which showed highly potent activities in inhibiting the SARS-CoV-2 S 26 protein-mediated cell-cell fusion and pseudovirus transduction. IPB02 also inhibited the 27 SARS-CoV pseudovirus efficiently. Moreover, the structure and activity relationship (SAR) 28 of IPB02 was characterized with a panel of truncated lipopeptides, revealing the amino acid 29 motifs critical for its binding and antiviral capacities. Therefore, the presented results have 30 provided important information for understanding the entry pathway of SARS-CoV-2 and the 31 design of antivirals that target the membrane fusion step. 32 33 Keywords: SARS-CoV-2; membrane fusion; fusion inhibitor; lipopeptide 34 35 on June 9, 2020 by guest http://jvi.asm.org/ Downloaded from 3 IMPORTANCE 36The COVID-19 pandemic caused by SARS-CoV-2 presents a serious global public health 37 emergency in urgent need of prophylactic and therapeutic interventions. The S protein of 38 coronaviruses mediates viral receptor-binding and membrane fusion thus being considered a 39 critical target for antivirals. Herein, we report that the SARS-CoV-2 S protein evolves a high 40 activity to mediate cell-cell fusion, significantly differing from the S protein of the previously 41 emerged SARS-CoV. In comparison, the HR1 sequence in the fusion protein of SARS-CoV-2 42 adopts a much higher helical stability and can interact with the HR2 site to form a six-helical 43 bundle structure more efficiently, underlying the mechanism of the enhanced fusion capacity. 44Also importantly, the design of membrane fusion inhibitors with high potencies against both 45 SARS-CoV-2 and SARS-CoV has provided potential arsenals to combat the pandemic and 46 tools to exploit the fusion mechanism. 47 65 homotrimeric class I fusion spike (S) protein to gain entry into host cells (7-9). The S protein 66 comprises of S1 and S2 subunits and exists in a metastable prefusion conformation. The S1 67 subunit, which contains a receptor-binding domain (RBD) capable of functional folding 68 independently, is responsible for virus binding to the cell surface receptor. A recent study 69 on June 9, 2020 by guest http://jvi.asm.org/ Downloaded from 5suggested that ACE2-binding affinity of the RBD of SARS-CoV-2 is up to 20-fold higher 70 than that of SARS-CoV, which may contribute to the significantl...

AbstractThe coronavirus disease COVID-19, caused by emerging SARS-CoV-2, has posed serious threats to global public health, economic and social stabilities, calling for the prompt development of therapeutics and prophylactics. In this study, we firstly verified that SARS-CoV-2 uses human ACE2 as a cell receptor and its spike (S) protein mediates high membrane fusion activity. Comparing to that of SARS-CoV, the heptad repeat 1 (HR1) sequence in the S2 fusion protein of SARS-CoV-2 possesses markedly increased α-helicity and thermostability, as well as a higher binding affinity with its corresponding heptad repeat 2 (HR1) site. Then, we designed a HR2 sequence-based lipopeptide fusion inhibitor, termed IPB02, which showed highly poent activities in inibibiting the SARS-CoV-2 S protein-mediated cell-cell fusion and pseudovirus infection. IPB02 also inhibited the SARS-CoV pseudovirus efficiently. Moreover, the strcuture and activity relationship (SAR) of IPB02 were characterzized with a panel of truncated lipopeptides, revealing the amino acid motifs critical for its binding and antiviral capacities. Therefore, the presented results have provided important information for understanding the entry pathway of SARS-CoV-2 and the design of antivirals that target the membrane fusion step.

DNA vaccines are simple to produce and can generate strong cellular and humoral immune response, making them attractive vaccine candidates. However, a major shortcoming of DNA vaccines is their poor immunogenicity when administered intramuscularly. Transcutaneous immunization (TCI) via microneedles is a promising alternative delivery route to enhance the vaccination efficacy. A novel dissolving microneedle array (DMA)-based TCI system loaded with cationic liposomes encapsulated with hepatitis B DNA vaccine and adjuvant CpG ODN was developed and characterized. The pGFP expression in mouse skin using DMA was imaged over time. In vivo immunity tests in mice were performed to observe the capability of DMA to induce immune response after delivery of DNA. The results showed that pGFP could be delivered into skin by DMA and expressed in skin. Further, the amount of expressed GFP was likely to peak at day 4. The immunity tests showed that the DMA-based DNA vaccination could induce effective immune response. CpG ODN significantly improved the immune response and achieved the shift of immune type from predominate Th2 type to a balance Th1/Th2 type. The cationic liposomes could further improve the immunogenicity of DNA vaccine. In conclusion, the novel DMA-based TCI system can effectively deliver hepatitis B DNA vaccine into skin, inducing effective immune response and change the immune type by adjuvant CpG ODN.

To investigate the single and joint effects of prepregnancy body mass index (BMI) and gestational weight gain (GWG) on pregnancy outcomes, electronic medical records of 14,196 women who delivered singleton live infant at a maternal and child health hospital in Beijing, China, in 2012 were reviewed. Logistic regression was used to assess the associations, adjusting for maternal age, height, education, parity, and offspring sex. Women of high prepregnancy BMI or excessive GWG had higher risks of gestational diabetes mellitus, hypertensive disorders in pregnancy, postpartum hemorrhage, caesarean delivery, macrosomia, and large for gestational age infant, while women of inadequate GWG had higher risks of preterm delivery, low birth weight, and small for gestational age infant. Findings suggest that antenatal care providers should help pregnant women control their GWG to normal.

The current COVID-19 pandemic is caused by SARS-CoV-2, a novel coronavirus genetically close to SARS-CoV, thus it is important to define the between antigenic cross-reactivity and neutralization. In this study, we first analyzed 20 convalescent serum samples collected from SARS-CoV infected individuals during the 2003 SARS outbreak. All patient sera reacted strongly with the S1 subunit and receptor-binding domain (RBD) of SARS-CoV, cross-reacted with the S ectodomain, S1, RBD, and S2 proteins of SARS-CoV-2, and neutralized both SARS-CoV and SARS-CoV-2 S protein-driven infections. Multiple panels of antisera from mice and rabbits immunized with a full-length S and RBD immunogens of SARS-CoV were also characterized, verifying the cross-reactive neutralization against SARS-CoV-2. Interestingly, we found that a palm civet SARS-CoV-derived RBD elicited more potent cross-neutralizing responses in immunized animals than the RBD from a human SARS-CoV strain, informing a strategy to develop universe vaccines against emerging CoVs.

The matrix (M) protein of Newcastle disease virus (NDV) is demonstrated to localize in the nucleus via intrinsic nuclear localization signal (NLS), but cellular proteins involved in the nuclear import of NDV M protein and the role of M's nuclear localization in the replication and pathogenicity of NDV remain unclear. In this study, importin β1 was screened to interact with NDV M protein by yeast two-hybrid screening. This interaction was subsequently confirmed by co-immunoprecipitation and pull-down assays. In vitro binding studies indicated that the NLS region of M protein and the amino acids 336–433 of importin β1 that belonged to the RanGTP binding region were important for binding. Importantly, a recombinant virus with M/NLS mutation resulted in a pathotype change of NDV and attenuated viral replication and pathogenicity in chicken fibroblasts and SPF chickens. In agreement with the binding data, nuclear import of NDV M protein in digitonin-permeabilized HeLa cells required both importin β1 and RanGTP. Interestingly, importin α5 was verified to interact with M protein through binding importin β1. However, importin β1 or importin α5 depletion by siRNA resulted in different results, which showed the obviously cytoplasmic or nuclear accumulation of M protein and the remarkably decreased or increased replication ability and pathogenicity of NDV in chicken fibroblasts, respectively. Our findings therefore demonstrate for the first time the nuclear import mechanism of NDV M protein and the negative regulation role of importin α5 in importin β1-mediated nuclear import of M protein and the replication and pathogenicity of a paramyxovirus.