Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 188
Filter
1.
Computer-Aided Civil & Infrastructure Engineering ; : 1, 2023.
Article in English | Academic Search Complete | ID: covidwho-20245341

ABSTRACT

Amid worsening passenger congestion, passenger flow control has become a major need in urban rail transit. However, existing passenger flow control strategies are fixed and do not consider the impacts of the spatial and temporal variations in passenger flow. To address the problems mentioned, a method for collaborative passenger flow control in urban rail transit is proposed. First, the temporal and spatial distribution of passengers in the network is obtained. Then, a model of collaborative passenger flow control for urban rail transit is built to reduce the number of controlled source points and controlled passengers and minimize the difference between the expected number of passengers on bottleneck links and the number of passengers with control. Next, a multilevel network that considers the time dimension is established based on the model. A forward–backward algorithm is introduced to make full use of the adaptive learning rate to solve the model. A case study based on a small‐scale network shows that the forward–backward algorithm has good convergence. To verify the effectiveness of the method, the passenger flow of Chengdu Metro during COVID‐19 is analyzed. The objective function of the forward–backward algorithm is 44% lower than that of the gradient descent method and 36% lower than that of adaptive moment estimate (ADAM). Its computational speed is also acceptable. The results show that compared with the fixed passenger flow control strategy of metro operators, the obtained strategy is more effective in reducing the number of controlled passengers and source points and alleviating congestion of bottleneck links. [ FROM AUTHOR] Copyright of Computer-Aided Civil & Infrastructure Engineering is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

2.
Sensors (Basel) ; 23(10)2023 May 10.
Article in English | MEDLINE | ID: covidwho-20245116

ABSTRACT

In the era of coronavirus disease (COVID-19), wearing a mask could effectively protect people from the risk of infection and largely reduce transmission in public places. To prevent the spread of the virus, instruments are needed in public places to monitor whether people are wearing masks, which has higher requirements for the accuracy and speed of detection algorithms. To meet the demand for high accuracy and real-time monitoring, we propose a single-stage approach based on YOLOv4 to identify the face and whether to regulate the wearing of masks. In this approach, we propose a new feature pyramidal network based on the attention mechanism to reduce the loss of object information that can be caused by sampling and pooling in convolutional neural networks. The network is able to deeply mine the feature map for spatial and communication factors, and the multi-scale feature fusion makes the feature map equipped with location and semantic information. Based on the complete intersection over union (CIoU), a penalty function based on the norm is proposed to improve positioning accuracy, which is more accurate at the detection of small objects; the new bounding box regression function is called Norm CIoU (NCIoU). This function is applicable to various object-detection bounding box regression tasks. A combination of the two functions to calculate the confidence loss is used to mitigate the problem of the algorithm bias towards determinating no objects in the image. Moreover, we provide a dataset for recognizing faces and masks (RFM) that includes 12,133 realistic images. The dataset contains three categories: face, standardized mask and non-standardized mask. Experiments conducted on the dataset demonstrate that the proposed approach achieves mAP@.5:.95 69.70% and AP75 73.80%, outperforming the compared methods.


Subject(s)
COVID-19 , Humans , Algorithms , Recognition, Psychology , Neural Networks, Computer , Communication
3.
Front Immunol ; 14: 1196031, 2023.
Article in English | MEDLINE | ID: covidwho-20236991

ABSTRACT

Swine acute diarrhoea syndrome coronavirus (SADS-CoV), which is a recently discovered enteric coronavirus, is the major aetiological agent that causes severe clinical diarrhoea and intestinal pathological damage in pigs, and it has caused significant economic losses to the swine industry. Nonstructural protein 5, also called 3C-like protease, cleaves viral polypeptides and host immune-related molecules to facilitate viral replication and immune evasion. Here, we demonstrated that SADS-CoV nsp5 significantly inhibits the Sendai virus (SEV)-induced production of IFN-ß and inflammatory cytokines. SADS-CoV nsp5 targets and cleaves mRNA-decapping enzyme 1a (DCP1A) via its protease activity to inhibit the IRF3 and NF-κB signaling pathways in order to decrease IFN-ß and inflammatory cytokine production. We found that the histidine 41 and cystine 144 residues of SADS-CoV nsp5 are critical for its cleavage activity. Additionally, a form of DCP1A with a mutation in the glutamine 343 residue is resistant to nsp5-mediated cleavage and has a stronger ability to inhibit SADS-CoV infection than wild-type DCP1A. In conclusion, our findings reveal that SADS-CoV nsp5 is an important interferon antagonist and enhance the understanding of immune evasion by alpha coronaviruses.


Subject(s)
Alphacoronavirus , Coronavirus , Interferon Type I , Animals , Swine , Alphacoronavirus/genetics , Alphacoronavirus/metabolism , Coronavirus/metabolism , Endopeptidases , Interferon Type I/metabolism
4.
J Virol ; 97(6): e0058923, 2023 Jun 29.
Article in English | MEDLINE | ID: covidwho-20236657

ABSTRACT

The inflammasome pathway is a critical early response mechanism of the host that detects pathogens, initiates the production of inflammatory cytokines, and recruits effector cells to the infection site. Nonetheless, the mechanism of inflammasome activation in coronavirus infection and its biological functions in host defense remain unclear. Transmissible gastroenteritis virus (TGEV), a member of the genus Alphacoronavirus, is a significant pathogen that mainly infects piglets and causes intestinal inflammation and inflammatory cell infiltration. Here, we investigated the mechanism of inflammasome activation in intestinal epithelial cells (IECs) infected with TGEV. We observed a substantial increase in interleukin 1ß (IL-1ß) and IL-18 levels in both IECs and TGEV-infected porcine intestinal tissues. Furthermore, TGEV infection resulted in increased activation of caspase-1 and the NLRP1 (NOD-like receptor [NLR]-containing pyrin domain [PYD]) inflammasome. Our findings revealed that TGEV infection impeded the interaction between porcine NLRP1 (pNLRP1) and porcine dipeptidyl peptidases 9 (pDPP9), yet it did not reduce the expression of pDPP9. Importantly, the ZU5 domain, not the function-to-find domain (FIIND) reported in human NLRP1, was identified as the minimal domain of pNLRP1 for pDPP9 binding. In addition, the robust type I IFN expression induced by TGEV infection also upregulated pNLRP1 expression and pNLRP1 itself acts as an interferon-stimulated gene to counteract TGEV infection. Our data demonstrate that pNLRP1 has antiviral capabilities against coronavirus infection, which highlights its potential as a novel therapeutic target for coronavirus antiviral therapy. IMPORTANCE Coronavirus primarily targets the epithelial cells of the respiratory and gastrointestinal tracts, leading to damage in both humans and animals. NLRP1 is a direct sensor for RNA virus infection which is highly expressed in epithelial barrier tissues. However, until recently, the precise molecular mechanisms underlying its activation in coronavirus infection and subsequent downstream events remained unclear. In this study, we demonstrate that the alphacoronavirus TGEV induces the production of IL-1ß and IL-18 and upregulates the expression of pNLRP1. Furthermore, we found that pNLRP1 can serve as an interferon-stimulated gene (ISG) to inhibit the infection of enterovirus TGEV. Our research highlights the crucial role of NLRP1 as a regulator of innate immunity in TGEV infection and shows that it may serve as a potential therapeutic target for the treatment of coronavirus infection.


Subject(s)
Gastroenteritis, Transmissible, of Swine , Inflammasomes , NLR Proteins , Transmissible gastroenteritis virus , Animals , Inflammasomes/immunology , Interferon Type I , Interleukin-18 , NLR Proteins/immunology , Swine , Gastroenteritis, Transmissible, of Swine/immunology , Gastroenteritis, Transmissible, of Swine/transmission
5.
Zhongguo Yufang Shouyi Xuebao / Chinese Journal of Preventive Veterinary Medicine ; 44(10):1076-1083, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2323056

ABSTRACT

Swine acute diarrhea syndrome coronavirus (SADS-CoV), a newly discovered enteric coronavirus, is the etiological agent that causes severe clinical diarrhea and intestinal pathological damage in piglets. In this study, Vero E6 and IPI-2I cells were pretreated with different concentrations of glycyrrhizin (GLY) for 2 hours, and then infected with different concentrations of SADSCoV, aiming to investigate the inhibitory effect of GLY on SADS-CoV. Western blot and TCID50 results revealed a significantly decreased N protein expression and viral titer, indicating that GLY can inhibit the infection of SADS-CoV. Vero E6 and IPI-2I cells were pretreated with different concentrations of GLY for 2 hours and infected with SADS-CoV. Western blot results showed that when the concentration of GLY was 0.8 mmol/L, the expression of N protein decreased significantly, indicating that GLY inhibited the invasion of the virus. At first, cells were treated with 0.4 mmol/L GLY, and cell samples were collected at 2 hours, 6 hours and 12 hours after being infected with SADS-CoV for analysis, and the expression of N protein were found to be significantly reduced at all points, indicating that GLY had a significant inhibitory effect on the replication of the virus. GLY is a competitive inhibitor of high mobility group box 1 (HMGB1), and the receptors of HMGB1 mainly include TLR4 and RAGE. Based on this fact, the mutant plasmid at the key sites of HMGB1 (C45S, C106S, C45/106S) and the siRNA of the RAGE receptor were transfected to Vero E6 cells and infected with SADS-CoV, and the cell supernatant and samples were harvested. The western blot and TCID50 results showed that the expression of N protein and the virus titer were decreased, suggesting that GLY exerts its function by affecting the binding of HMGB1/TLR4/RAGE during SADS-CoV infection. To further explore the signaling pathway through which GLY functions, Vero E6 and IPI-2I cells were inoculated with SADS-CoV, and cell samples were harvested, western blot was used to detect the changes of MAPK proteins. The results showed that the protein expression levels of p-p38, p-JNK and p-ERK were up-regulated in the early and late stages, indicating that the MAPK pathway was activated by SADS-CoV infection. Vero E6 and IPI-2I were pretreated with different concentrations of GLY and TLR4 inhibitor TAK for 2 hours and infected with SADS-CoV. Protein samples were harvested and analysed by western blot which showed a decreased p-JNK and N proteins, while other proteins showed no significant changes. These results indicated that GLY and TAK regulated the phosphorylation of JNK but did not regulate the phosphorylation of p38 and ERK. Also, Vero E6 cells were treated with HMGB1 antibody, the siRNA of HMGB1 and HMGB1 mutants plasmid, and infected with SADS-CoV. Protein samples were harvested, western blot results showed that phosphorylation of JNK decreased, indicating that HMGB1 affected JNK phosphorylation. Finally, Vero E6 and IPI-2I cells were pretreated with different concentrations of JNK inhibitor SP600125 to infect SADS-CoV, western blot, TCID50 and IFA results showed that the expression of N protein and virus titer, as well as virus replication were reduced, indicating that SP600125 inhibited virus replication. In conclusion, our results revealed that GLY can inhibit in vitro replication of SADS- CoV, mainly through the HMGB1/TLR4/JNK signaling pathway. The discovery of this pathway provides theoretical support for the research of novel anti-SADS-CoV drugs.

6.
Front Public Health ; 11: 1124915, 2023.
Article in English | MEDLINE | ID: covidwho-2326992

ABSTRACT

Background: Lower psychological wellbeing is associated with poor outcomes in a variety of diseases and healthy populations. However, no study has investigated whether psychological wellbeing is associated with the outcomes of COVID-19. This study aimed to determine whether individuals with lower psychological wellbeing are more at risk for poor outcomes of COVID-19. Methods: Data were from the Survey of Health, Aging, and Retirement in Europe (SHARE) in 2017 and SHARE's two COVID-19 surveys in June-September 2020 and June-August 2021. Psychological wellbeing was measured using the CASP-12 scale in 2017. The associations of the CASP-12 score with COVID-19 hospitalization and mortality were assessed using logistic models adjusted for age, sex, body mass index, smoking, physical activity, household income, education level, and chronic conditions. Sensitivity analyses were performed by imputing missing data or excluding cases whose diagnosis of COVID-19 was solely based on symptoms. A confirmatory analysis was conducted using data from the English Longitudinal Study of Aging (ELSA). Data analysis took place in October 2022. Results: In total, 3,886 individuals of 50 years of age or older with COVID-19 were included from 25 European countries and Israel, with 580 hospitalized (14.9%) and 100 deaths (2.6%). Compared with individuals in tertile 3 (highest) of the CASP-12 score, the adjusted odds ratios (ORs) of COVID-19 hospitalization were 1.81 (95% CI, 1.41-2.31) for those in tertile 1 (lowest) and 1.37 (95% CI, 1.07-1.75) for those in tertile 2. As for COVID-19 mortality, the adjusted ORs were 2.05 (95% CI, 1.12-3.77) for tertile 1 and 1.78 (95% CI, 0.98-3.23) for tertile 2, compared with tertile 3. The results were relatively robust to missing data or the exclusion of cases solely based on symptoms. This inverse association of the CASP-12 score with COVID-19 hospitalization risk was also observed in ELSA. Conclusion: This study shows that lower psychological wellbeing is independently associated with increased risks of COVID-19 hospitalization and mortality in European adults aged 50 years or older. Further study is needed to validate these associations in recent and future waves of the COVID-19 pandemic and other populations.


Subject(s)
COVID-19 , Humans , Adult , Middle Aged , COVID-19/epidemiology , Longitudinal Studies , Israel/epidemiology , Pandemics , Risk Factors , Hospitalization , Europe/epidemiology
7.
Neurology ; 100(23): e2409-e2423, 2023 06 06.
Article in English | MEDLINE | ID: covidwho-2313525

ABSTRACT

BACKGROUND AND OBJECTIVES: Post-COVID condition (PCC) is common and often involves neuropsychiatric symptoms. This study aimed to use blood oxygenation level-dependent fMRI (BOLD-fMRI) to assess whether participants with PCC had abnormal brain activation during working memory (WM) and whether the abnormal brain activation could predict cognitive performance, motor function, or psychiatric symptoms. METHODS: The participants with PCC had documented coronavirus disease 2019 (COVID-19) at least 6 weeks before enrollment. Healthy control participants had no prior history of COVID-19 and negative tests for severe acute respiratory syndrome coronavirus 2. Participants were assessed using 3 NIH Toolbox (NIHTB) batteries for Cognition (NIHTB-CB), Emotion (NIHTB-EB), and Motor function (NIHTB-MB) and selected tests from the Patient-Reported Outcomes Measurement Information System (PROMIS). Each had BOLD-fMRI at 3T, during WM (N-back) tasks with increasing attentional/WM load. RESULTS: One hundred sixty-nine participants were screened; 50 fulfilled the study criteria and had complete and usable data sets for this cross-sectional cohort study. Twenty-nine participants with PCC were diagnosed with COVID-19 242 ± 156 days earlier; they had similar ages (42 ± 12 vs 41 ± 12 years), gender proportion (65% vs 57%), racial/ethnic distribution, handedness, education, and socioeconomic status, as the 21 uninfected healthy controls. Despite the high prevalence of memory (79%) and concentration (93%) complaints, the PCC group had similar performance on the NIHTB-CB as the controls. However, participants with PCC had greater brain activation than the controls across the network (false discovery rate-corrected p = 0.003, Tmax = 4.17), with greater activation in the right superior frontal gyrus (p = 0.009, Cohen d = 0.81, 95% CI 0.15-1.46) but lesser deactivation in the default mode regions (p = 0.001, d = 1.03, 95% CI 0.61-1.99). Compared with controls, participants with PCC also had poorer dexterity and endurance on the NIHTB-MB, higher T scores for negative affect and perceived stress, but lower T scores for psychological well-being on the NIHTB-EB, as well as more pain symptoms and poorer mental and physical health on measures from the PROMIS. Greater brain activation predicted poorer scores on measures that were abnormal on the NIHTB-EB. DISCUSSION: Participants with PCC and neuropsychiatric symptoms demonstrated compensatory neural processes with greater usage of alternate brain regions, and reorganized networks, to maintain normal performance during WM tasks. BOLD-fMRI was sensitive for detecting brain abnormalities that correlated with various quantitative neuropsychiatric symptoms.


Subject(s)
COVID-19 , Memory, Short-Term , Humans , Memory, Short-Term/physiology , Post-Acute COVID-19 Syndrome , Cross-Sectional Studies , Brain/diagnostic imaging , Magnetic Resonance Imaging , Neuropsychological Tests
8.
Cogn Sci ; 47(5): e13294, 2023 05.
Article in English | MEDLINE | ID: covidwho-2316745

ABSTRACT

People are known for good predictions in domains they have rich experience with, such as everyday statistics and intuitive physics. But how well can they predict for problems they lack experience with, such as the duration of an ongoing epidemic caused by a new virus? Amid the first wave of COVID-19 in China, we conducted an online diary study, asking each of over 400 participants to predict the remaining duration of the epidemic, once per day for 14 days. Participants' predictions reflected a reasonable use of publicly available information but were meanwhile biased, subject to the influence of negative affect and future time perspectives. Computational modeling revealed that participants neither relied on prior distributions of epidemic durations as in inferring everyday statistics, nor on mechanistic simulations of epidemic dynamics as in computing intuitive physics. Instead, with minimal experience, participants' predictions were best explained by similarity-based generalization of the temporal pattern of epidemic statistics. In two control experiments, we further confirmed that such cognitive algorithm is not specific to the epidemic scenario and that minimal and rich experience do lead to different prediction behaviors for the same observations. We conclude that people generalize patterns in recent history to predict the future under minimal experience.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Generalization, Psychological , Computer Simulation , China/epidemiology
9.
Front Immunol ; 13: 976512, 2022.
Article in English | MEDLINE | ID: covidwho-2320841

ABSTRACT

COVID-19 prognoses suggests that a proportion of patients develop fibrosis, but there is no evidence to indicate whether patients have progression of mesenchymal transition (MT) in the lungs. The role of MT during the COVID-19 pandemic remains poorly understood. Using single-cell RNA sequencing, we profiled the transcriptomes of cells from the lungs of healthy individuals (n = 45), COVID-19 patients (n = 58), and idiopathic pulmonary fibrosis (IPF) patients (n = 64) human lungs to map the entire MT change. This analysis enabled us to map all high-resolution matrix-producing cells and identify distinct subpopulations of endothelial cells (ECs) and epithelial cells as the primary cellular sources of MT clusters during COVID-19. For the first time, we have identied early and late subgroups of endothelial mesenchymal transition (EndMT) and epithelial-mesenchymal transition (EMT) using analysis of public databases for single-cell sequencing. We assessed epithelial subgroups by age, smoking status, and gender, and the data suggest that the proportional changes in EMT in COVID-19 are statistically significant. Further enumeration of early and late EMT suggests a correlation between invasive genes and COVID-19. Finally, EndMT is upregulated in COVID-19 patients and enriched for more inflammatory cytokines. Further, by classifying EndMT as early or late stages, we found that early EndMT was positively correlated with entry factors but this was not true for late EndMT. Exploring the MT state of may help to mitigate the fibrosis impact of SARS-CoV-2 infection.


Subject(s)
COVID-19 , Epithelial-Mesenchymal Transition , Cytokines , Endothelial Cells/pathology , Epithelial-Mesenchymal Transition/genetics , Fibrosis , Humans , Pandemics , SARS-CoV-2 , Signal Transduction
10.
Natl Sci Rev ; 10(5): nwac034, 2023 May.
Article in English | MEDLINE | ID: covidwho-2311829

ABSTRACT

The onset of various kidney diseases has been reported after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. However, detailed clinical and pathological features are lacking. We screened and analyzed patients with newly diagnosed kidney diseases after inactivated SARS-CoV-2 vaccination in Peking University First Hospital from January 2021 to August 2021, and compared them with the reported cases in the literature. We obtained samples of blood, urine and renal biopsy tissues. Clinical and laboratory information, as well as light microscopy, immunostaining and ultrastructural observations, were described. The SARS-CoV-2 spike protein and nucleoprotein were stained using the immunofluorescence technique in the kidney biopsy samples. SARS-CoV-2 specific antibodies were tested using magnetic particle chemiluminescence immunoassay. The study group included 17 patients with a range of conditions including immune-complex-mediated kidney diseases (IgA nephropathy, membranous nephropathy and lupus nephritis), podocytopathy (minimal change disease and focal segmental glomerulosclerosis) and others (antineutrophil-cytoplasmic-antibody-associated vasculitis, anti-glomerular basement membrane nephritis, acute tubulointerstitial nephritis and thrombotic microangiopathy). Seven patients (41.18%) developed renal disease after the first dose and ten (58.82%) after the second dose. The kidney disease spectrum as well as clinicopathological features are similar across different types of SARS-CoV-2 vaccines. We found no definitive evidence of SARS-CoV-2 spike protein or nucleoprotein deposition in the kidney biopsy samples. Seropositive markers implicated abnormal immune responses in predisposed individuals. Treatment and follow-up (median = 86 days) showed that biopsy diagnosis informed treatment and prognosis in all patients. In conclusion, we observed various kidney diseases following SARS-CoV-2 vaccine administration, which show a high consistency across different types of SARS-CoV-2 vaccines. Our findings provide evidence against direct vaccine protein deposition as the major pathomechanism, but implicate abnormal immune responses in predisposed individuals. These findings expand our understanding of SARS-CoV-2 vaccine renal safety.

11.
International journal of molecular sciences ; 24(8), 2023.
Article in English | EuropePMC | ID: covidwho-2295334

ABSTRACT

Nucleocapsid protein (N protein) is an appropriate target for early determination of viral antigen-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We have found that β-cyclodextrin polymer (β-CDP) has shown a significant fluorescence enhancement effect for fluorophore pyrene via host–guest interaction. Herein, we developed a sensitive and selective N protein-sensing method that combined the host–guest interaction fluorescence enhancement strategy with high recognition of aptamer. The DNA aptamer of N protein modified with pyrene at its 3′ terminal was designed as the sensing probe. The added exonuclease I (Exo I) could digest the probe, and the obtained free pyrene as a guest could easily enter into the hydrophobic cavity of host β-CDP, thus inducing outstanding luminescent enhancement. While in the presence of N protein, the probe could combine with it to form a complex owing to the high affinity between the aptamer and the target, which prevented the digestion of Exo I. The steric hindrance of the complex prevented pyrene from entering the cavity of β-CDP, resulting in a tiny fluorescence change. N protein has been selectively analyzed with a low detection limit (11.27 nM) through the detection of the fluorescence intensity. Moreover, the sensing of spiked N protein from human serum and throat swabs samples of three volunteers has been achieved. These results indicated that our proposed method has broad application prospects for early diagnosis of coronavirus disease 2019.

12.
Front Public Health ; 11: 1145749, 2023.
Article in English | MEDLINE | ID: covidwho-2305541

ABSTRACT

Possible improvements to the doctor-patient relationship are an important subject confronting national healthcare policy and health institutions. In recent years, online healthcare communities have changed the ways in which doctors and patients communicate, especially during the COVID-19 pandemic. However, previous research on how usage of online healthcare communities has affected the doctor-patient relationship is rather limited. This paper proposes a research model to investigate the relationship between online healthcare community usage and the doctor-patient relationship. An analysis of 313 patients' data using structural equation modeling showed the following. First, the use of an online healthcare community has a positive impact on doctor-patient communication, helps improve the performance of healthcare procedures, and reduces healthcare costs. Second, doctor-patient communication and healthcare costs have a positive impact on patients' emotional dependence and patients' perception of healthcare quality, while healthcare procedures do not have this impact. Finally, patients' emotional dependence and perception of healthcare quality have a positive effect on doctor-patient relationship through the mediator of patients' satisfaction.


Subject(s)
COVID-19 , Physicians , Humans , Physician-Patient Relations , Pandemics , COVID-19/epidemiology , Physicians/psychology , China
13.
Int J Mol Sci ; 24(8)2023 Apr 12.
Article in English | MEDLINE | ID: covidwho-2295333

ABSTRACT

Nucleocapsid protein (N protein) is an appropriate target for early determination of viral antigen-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We have found that ß-cyclodextrin polymer (ß-CDP) has shown a significant fluorescence enhancement effect for fluorophore pyrene via host-guest interaction. Herein, we developed a sensitive and selective N protein-sensing method that combined the host-guest interaction fluorescence enhancement strategy with high recognition of aptamer. The DNA aptamer of N protein modified with pyrene at its 3' terminal was designed as the sensing probe. The added exonuclease I (Exo I) could digest the probe, and the obtained free pyrene as a guest could easily enter into the hydrophobic cavity of host ß-CDP, thus inducing outstanding luminescent enhancement. While in the presence of N protein, the probe could combine with it to form a complex owing to the high affinity between the aptamer and the target, which prevented the digestion of Exo I. The steric hindrance of the complex prevented pyrene from entering the cavity of ß-CDP, resulting in a tiny fluorescence change. N protein has been selectively analyzed with a low detection limit (11.27 nM) through the detection of the fluorescence intensity. Moreover, the sensing of spiked N protein from human serum and throat swabs samples of three volunteers has been achieved. These results indicated that our proposed method has broad application prospects for early diagnosis of coronavirus disease 2019.


Subject(s)
COVID-19 , Polymers , Humans , Polymers/chemistry , SARS-CoV-2 , Fluorescence , COVID-19/diagnosis , Pyrenes/chemistry
14.
Emerg Microbes Infect ; 12(1): 2202269, 2023 Dec.
Article in English | MEDLINE | ID: covidwho-2294850

ABSTRACT

Breakthrough infections by SARS-CoV-2 variants pose a global challenge to COVID-19 pandemic control, and the development of more effective vaccines of broad-spectrum protection is needed. In this study, we constructed pVAX1-based plasmids encoding receptor-binding domain (RBD) chimera of SARS-CoV-1 and SARS-CoV-2 variants, including pAD1002 (encoding RBDSARS/BA1), pAD1003 (encoding RBDSARS/Beta) and pAD131 (encoding RBDBA1/Beta). Plasmids pAD1002 and pAD131 were far more immunogenic than pAD1003 in terms of eliciting RBD-specific IgG when intramuscularly administered without electroporation. Furthermore, dissolvable microneedle array patches (MAP) greatly enhanced the immunogenicity of these DNA constructs in mice and rabbits. MAP laden with pAD1002 (MAP-1002) significantly outperformed inactivated SARS-CoV-2 virus vaccine in inducing RBD-specific IFN-γ+ effector and memory T cells, and generated T lymphocytes of different homing patterns compared to that induced by electroporated DNA in mice. In consistence with the high titer neutralization results of MAP-1002 antisera against SARS-CoV-2 pseudoviruses, MAP-1002 protected human ACE2-transgenic mice from Omicron BA.1 challenge. Collectively, MAP-based DNA constructs encoding chimeric RBDs of SARS-CoV-1 and SARS-CoV-2 variants, as represented by MAP-1002, are potential COVID-19 vaccine candidates worthy further translational study.


Subject(s)
COVID-19 , Severe acute respiratory syndrome-related coronavirus , Vaccines, DNA , Animals , Humans , Mice , Rabbits , COVID-19 Vaccines , SARS-CoV-2 , Pandemics , DNA , Mice, Transgenic , Antibodies, Viral , Antibodies, Neutralizing , Spike Glycoprotein, Coronavirus
15.
Vaccines (Basel) ; 11(4)2023 Mar 31.
Article in English | MEDLINE | ID: covidwho-2294307

ABSTRACT

Waves of breakthrough infections by SARS-CoV-2 Omicron subvariants currently pose a global challenge to the control of the COVID-19 pandemic. We previously reported a pVAX1-based DNA vaccine candidate, pAD1002, that encodes a receptor-binding domain (RBD) chimera of SARS-CoV-1 and Omicron BA.1. In mouse and rabbit models, pAD1002 plasmid induced cross-neutralizing Abs against heterologous sarbecoviruses, including SARS-CoV-1 and SARS-CoV-2 wildtype, Delta and Omicron variants. However, these antisera failed to block the recent emerging Omicron subvariants BF.7 and BQ.1. To solve this problem, we replaced the BA.1 RBD-encoding DNA sequence in pAD1002 with that of BA.4/5. The resulting construct, namely pAD1016, elicited SARS-CoV-1 and SARS-CoV-2 RBD-specific IFN-γ+ cellular responses in BALB/c and C57BL/6 mice. More importantly, pAD1016 vaccination in mice, rabbits and pigs generated serum Abs capable of neutralizing pseudoviruses representing multiple SARS-CoV-2 Omicron subvariants including BA.2, BA.4/5, BF.7, BQ.1 and XBB. As a booster vaccine for inactivated SARS-CoV-2 virus preimmunization in mice, pAD1016 broadened the serum Ab neutralization spectrum to cover the Omicron BA.4/5, BF7 and BQ.1 subvariants. These preliminary data highlight the potential benefit of pAD1016 in eliciting neutralizing Abs against broad-spectrum Omicron subvariants in individuals previously vaccinated with inactivated prototype SARS-CoV-2 virus and suggests that pAD1016 is worthy of further translational study as a COVID-19 vaccine candidate.

16.
J Biomol Struct Dyn ; : 1-10, 2023 Apr 12.
Article in English | MEDLINE | ID: covidwho-2306463

ABSTRACT

Antibodies that recognize the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), especially the neutralizing antibodies, carry great hope in the treatment and final elimination of COVID-19. Driven by a synchronized global effort, thousands of antibodies against the spike protein have been identified during the past two years, with the structural information available at atomistic detail for hundreds of these antibodies. We developed an improved molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) method including explicitly treated interfacial water to calculate the binding free energy between representative antibodies and the receptor binding domain (RBD) domain of SARS-COV-2 spike proteins. We discovered that explicit treatment of water molecules located at the interface between RBD and antibody effectively improves the results for the WT and variants of concern (VOC) systems. Interfacial water molecules, together with surface and internal water molecules, behave drastically from bulk water and exert peculiar impacts on protein dynamics and energy, and thus warrant explicit treatment to complement implicit solvent models. Our results illustrate the importance of including interfacial water molecules to approach efficient and reliable prediction of binding free energy.Communicated by Ramaswamy H. Sarma.

17.
Process Saf Environ Prot ; 174: 548-560, 2023 Jun.
Article in English | MEDLINE | ID: covidwho-2306460

ABSTRACT

Aerosols such as PM2.5 and PM10 can have an immense impact on human health. With the outbreak of SARS-CoV-2, it is urgent to filter aerosols by media filtration technology. Electrospun nanofibers are a promising material for achieving high efficiency, low resistance, light weight, and environmentally friendly air filtration. But research on filtration theory and computer simulation of nanofiber media is still lacking. The traditional method involving computational fluid dynamics (CFD) and Maxwell's first-order slip boundary overestimates the slip velocity on the fiber surface. In this study, a new modified slip boundary was proposed, which introduced a slip velocity coefficient on the basis of the no-slip boundary to address the slip wall. Our simulation results were compared with the experimental pressure drop and particle capture efficiency of real polyacrylonitrile (PAN) nanofiber media. The computational accuracy on pressure drop of the modified slip boundary improved 24.6% and 11.2% compared with that of the no-slip boundary and Maxwell's first-order slip boundary, respectively. It was found that the particle capture efficiency near the most-penetrating particle size (MPPS) was significantly increased when slip effect occurred. This may be explained by the slip velocity on the fiber surface, which would make particles more accessible to the fiber surface and captured by interception.

18.
Microbiol Spectr ; 11(3): e0404422, 2023 Jun 15.
Article in English | MEDLINE | ID: covidwho-2306459

ABSTRACT

Early detection of microbial pathogens causing respiratory tract infection plays a crucial role in clinical management. The BioCode Respiratory Pathogen Panel (BioCode RPP) utilizes reverse transcriptase PCR (RT-PCR) in combination with barcoded magnetic beads to amplify, detect, and identify respiratory pathogens. This panel qualitatively detects and identifies 14 viruses, including influenza virus A with H1 pdm09, H1, and H3 subtyping; influenza B; respiratory syncytial virus (RSV); human metapneumovirus; parainfluenza virus 1; parainfluenza virus 2; parainfluenza virus 3; parainfluenza virus 4; coronavirus (229E, NL63, OC43, and HKU1); adenovirus; and human rhinovirus/enterovirus, and 3 bacteria, including Chlamydia pneumoniae, Mycoplasma pneumoniae, and Bordetella pertussis. Reproducibility, which was assessed with contrived specimens containing 12 targets at 3 clinical sites, with 2 operators at each site for 5 days, was 99.4% for Flu A H3 and Flu B, 98.9% for RSV, and 100% for the remaining 9 targets assayed. A multicenter clinical trial evaluated the performance of the BioCode RPP with 2,647 nasopharyngeal swab specimens from 5 geographically distinct sites and revealed comparable performance between the BioCode RPP and FilmArray Respiratory Panel (FA-RP). Specifically, the positive percent agreements (PPAs) for various pathogens ranged between 80.8% and 100% compared with the FA-RP (1.7 and 2.0). Negative percent agreement ranged from 98.4% to 100% for BioCode RPP. The BioCode RPP also offers scalable automated testing capability of up to 96 specimens in a single run with total sample-to-result time under 5 h. The invalid rate of the BioCode RPP on initial testing was 1.0% (26/2,649). IMPORTANCE Early detection of microbial pathogens causing respiratory tract infection plays a crucial role in clinical management. The BioCode Respiratory Pathogen Panel (BioCode RPP) is a high-throughput test that utilizes RT-PCR in combination with barcoded magnetic beads to amplify, detect, and identify 17 respiratory pathogens, including 14 viruses and 3 bacteria. This study summarizes data generated from a multicenter clinical trial evaluating the performance of the BioCode RPP on 2,647 nasopharyngeal swab specimens from five geographically distinct sites.


Subject(s)
Paramyxoviridae Infections , Respiratory Syncytial Virus, Human , Respiratory Tract Infections , Virus Diseases , Viruses , Humans , Virus Diseases/diagnosis , Reproducibility of Results , Viruses/genetics , Bacteria , Respiratory Tract Infections/microbiology , Nasopharynx
19.
Front Endocrinol (Lausanne) ; 14: 1073878, 2023.
Article in English | MEDLINE | ID: covidwho-2306422

ABSTRACT

Type 2 diabetes mellitus (T2DM) is a widespread metabolic condition with a high global morbidity and mortality rate that affects the whole body. Their primary consequences are mostly caused by the macrovascular and microvascular bed degradation brought on by metabolic, hemodynamic, and inflammatory variables. However, research in recent years has expanded the target organ in T2DM to include the lung. Inflammatory lung diseases also impose a severe financial burden on global healthcare. T2DM has long been recognized as a significant comorbidity that influences the course of various respiratory disorders and their disease progress. The pathogenesis of the glycemic metabolic problem and endothelial microangiopathy of the respiratory disorders have garnered more attention lately, indicating that the two ailments have a shared history. This review aims to outline the connection between T2DM related endothelial cell dysfunction and concomitant respiratory diseases, including Coronavirus disease 2019 (COVID-19), asthma, chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF).


Subject(s)
COVID-19 , Diabetes Mellitus, Type 2 , Diabetic Angiopathies , Idiopathic Pulmonary Fibrosis , Pulmonary Disease, Chronic Obstructive , Vascular Diseases , Humans , Diabetes Mellitus, Type 2/complications , COVID-19/complications , Lung/pathology , Comorbidity , Idiopathic Pulmonary Fibrosis/pathology
20.
International Journal of Sustainable Transportation ; 17(4):382-392, 2023.
Article in English | Academic Search Complete | ID: covidwho-2270101

ABSTRACT

One of the most challenging issues confronting tour operators is how to improve consumers' travel intention after the COVID-19 pandemic. Considering the immediacy of the situation, existing studies exploring this problem are necessarily limited. Based on a theory of reasoned action, this paper proposes a research model to investigate factors influencing consumers' travel intentions in the wake of the pandemic. Using structural equation modeling analysis of 826 consumers in China, the results showed that: (1) physical risk had the greatest negative impact on consumers' attitudes toward travel, followed by psychological risk;(2) physical risk had a negative effect on consumers' subjective norms, while the effect of psychological risk on consumers' subjective norms was not significant;(3) risk perception, including physical and psychological risk, affected consumers' travel intentions through subjective norms and attitudes;and (4) consumers' perceptions of the seriousness of the pandemic and travel experience act as a negative moderators between attitude toward travel and travel intentions. The conclusions of this study provide vital information for tour operators to create viable and sustainable operations in this time of crisis. [ABSTRACT FROM AUTHOR] Copyright of International Journal of Sustainable Transportation is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

SELECTION OF CITATIONS
SEARCH DETAIL