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This study aims to explore university students' continuous intention toward online learning during COVID-19 pandemic. A total of 120 students enrolled in online learning were surveyed to collect their perception of an extended model by adding task value to the expectation-confirmation model. Structural equation modeling was employed to verify the hypotheses proposed in this study. The results indicated that task value and technology usefulness were significant predictors of students' continuous intention toward online learning. More specifically, technology usefulness had a direct impact on students' continuous intention, while students' perceived task value played an indirect role in the prediction of their continuous intention. However, the impacts of both confirmation and satisfaction were not statistically significant on students' continuous intention. The results suggest that practitioners and researchers should pay special attention to the technological usefulness of online learning environments and task value, especially task value, in order to enhance students' retention of online learning. This study would contribute to implications to better design and implement online learning. © 2023 IEEE.
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Background: Diarrhea was typical symptoms of the coronavirus disease 2019 (COVID-19). However, the underlying mechanism had not been fully understood. Aim(s): The study aimed to explore the mechanism of intestinal injury during COVID-19 in a coronavirus murine hepatitis virus strain 3 (MHV-3) induced acute mouse model. Method(s): MHV-3 induced acute infection Balb/cJ mice model was established. Intestine samples were collected at indicated time points as 0 h, 24 h, 48 h and 60 h post infection. The mRNA and protein expression of IL1b, TNFalpha, IL6, caspase 3 and cleaved caspase 3 were examined by real-time quantitative PCR (qPCR) and western blot respectively. The intestine injury and apoptosis were measured by HE staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Moreover, Z-DEVD-FMK (caspase 3 inhibitor) pre-treated MHV-3 infection mice model were established, in which the apoptosis of intestine was evaluated as well. Meanwhile, the murine intestinal cell MODE-K was infected by MHV-3 in vitro for evaluation of virus induced apoptosis. Result(s): Post MHV-3 infection, the histopathology of intestine tissue showed extraordinary injury with time dependence, as well as high level of TUNEL positivity. The mRNA levels of inflammatory cytokine IL1b, TNFalpha and IL6 were significantly increased. The protein expressions of caspase 3 and cleaved caspase 3 in the intestine was found significantly elevated from 24 to 48 h post MHV-3 infection. Z-DEVD-FMK pretreatment inhibited caspase 3 and cleaved caspase 3 expression and decreased TUNEL positivity. Meanwhile, alleviated gut injury and inhibited TNFalpha expression were observed. In vitro treated by MHV-3, intestinal cell line MODE-K showed nine-fold increase of apoptosis by comparison with saline treated ones. The expressions of apoptosis crucial protein caspase3 and cleaved caspase3 significantly elevated, as well as TNFalpha. Conclusion(s): Coronavirus murine hepatitis virus strain 3 induces intestinal injury via caspase 3 dependent apoptosis, which might shed light on the treatment of intestinal complications in COVID-19.
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This paper is an attempt to customize a lightweight model to classify pneumonia images by integrating depthwise-separable convolutions with typical CNN model, and focus on the performance of DSCNN in comparison with typical CNN model based on X-ray images. The experimental result shows that in our four-layer structure, DSCNN reduce around 50,000 parameters compared to CNN. But DSCNN had a relative low recall on COVID-19(89.23%). However, with proper means of optimization such as focal loss and data augmentation, there was a slight increase in test accuracy of DSCNN(from 95.25% to 96.14%), and a significant increase in recall on COVID-19(from 89.23% to 94.61%). And this model also performed well on the rest two labels. © 2022 IEEE.
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Background: A virus is a tiny agent, around one-hundredth the size of a bacterium which can infect cells of plants and animals. Seven coronaviruses are known to infect humans;three of them are serious, namely, SARS (severe acute respiratory syndrome, China, 2002), MERS (Middle East respiratory syndrome, Saudi Arabia, 2012), and SARS-CoV-2 (COVID-19) (2019-2020). SARS-CoV and MERS-CoV belong to beta coronaviruses (betaCoVs). Objective(s): In this mini-review, we want to consider the importance of vitamin D and C, especially plants containing these two vitamins, in the fight against COVID-19. Method(s): The manuscript includes review articles, randomized control experiments, analytical studies, and observations, which have been gathered from different sources such as Google Scholar, Scopus, Science Direct, and PubMed. A literature review was carried out using keywords such as vitamin D, vitamin C, COVID-19, influenza, plant, and coronaviruses. Result(s): Various sources of vitamin D for humans are food, dietary supplements, and the skin by exposure to 7-dehydrocholesterol to ultraviolet light. There are some new findings on the influence of vitamin D in preventing and controlling influenza and COVID-19. Vitamin D may play a role in preventing influenza and COVID-19 by producing large quantities of IL-1 and IL-6 or interleukins. Conclusion(s): Vitamin D deficiency is a potential link between respiratory infection and immune eva-sion, and vitamin D is a pleiotropic factor known to modulate the immune response against the patho-gen. Copyright © 2023 Bentham Science Publishers.
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In this mini-review article, we have mentioned the key roles of some of the most important herbal plants medicine containing flavonoids and phytochemicals with antiviral activities. All relevant information was searched by using the terms, influenza, phytochemicals, SARS, SARSCov-2, flavonoids, and traditional medicinal plants uses, from reliable databases, such as PubMed, Science Direct, and Google Scholar. The most important medicinal herbs which contain flavonoids with antiviral activities are Limonium densiflorum, Oroxylum indicum, Tribulus terrestris L., Paulownia tomentosa Steud., Allophylus africanus, Houttuynia cordata, Moslea Herba, Mosla scabra, Scutellaria baicalensis, Berries, Genus Psoralea, Sophora tonkinensis, Trollius chinensis, Tilia cordata, Hippophae rhamnoides L. (Seabuckthorn), Paulownia tomentosa steud, and C. swietenia. Phytochemicals are chemicals of plant origin produced by plants through primary or secondary metabolism. The most important medicinal plants, which contain phytochemicals with antiviral activities are chinensis, Sanguinaria Canadensis, Dodonaea viscosa, Isatis indigotica, Pelargonium sidoides, Entada Africana Guill., Pomegranate (Punica granatum), Goldenseal (Hydrastis canadensis), Lychee nium sanguineum L., and Tea polyphenols. Natural products from traditional herbal medicines, especially traditional Chinese and Persian medicines, have been found to exert antiviral impacts against influenza and human coronaviruses. The natural plant-derived compounds that have been used for treating various diseases are flavonoids and phytochemicals.
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There always exists non-coding and missing sequence in obtained gene sequence data. The existing gene sequence representation methods extract features from high dimension gene sequence mostly through manual process, which usually are computationally expensive. What's more, the precision of prediction heavily relies on how to utilize the biology background knowledge. In this work, we construct a gene sequence representation method based on graph context information in virus transmission network. After coding the target node's virus sequence, we use attention mechanism to aggregate the neighbor nodes' gene sequence information, and thus we can achieve a new representation of the target node's gene sequence. The gene sequence representation model is optimized based on the fact that the similarity of gene sequence of neighbor nodes is higher than that of non-neighbor nodes. The new representation after being well trained not only extracts the feature of sequence exactly, but also reduces the dimension of gene sequence greatly and improve the computation efficiency. We first train the gene sequence representation model respectively on a simulation transmission network, SARS-CoV-2 and HIV transmission network, and then predict the un-sampled infections in each transmission network. The experimental results show the effectiveness of our model, and its performance is better than other models. What's more, its success on effectively predicting the un-sampled infections in virus transmission network has a certain practical significance in the epidemiological investigation area. © 2021, Science Press. All right reserved.
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This study presents a new method to analyse the impact of exogenous shock and its transmission mechanism within the global production network, based on scenarios of the COVID-19 pandemic. We decompose domestic and international technology spillovers and introduce them into an economic growth model to investigate the elasticities of factor inputs and knowledge spillovers through industrial linkages, and eventually estimate a model with spatial specifications. The results from the scenario simulations suggest that the global total output is projected to fall by 3.60% and 8.41% under the V-shaped and L-shaped recovery scenarios, respectively, and that the propagation through input-output linkages is an important channel that causes global economic fluctuations. Economies at the hub of the production network, that is, the United States, China, and Germany, are the most seriously affected. Structural decomposition analysis results indicate that the shortage of intermediate inputs supply is the main driver of output decline, followed by the blockage of technology diffusion, and lastly, the reduction of labour supply. © 2021 Informa UK Limited, trading as Taylor & Francis Group.
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The ongoing COVID-19 pandemic has led to a serious health crisis, and information obtained from disease transmission models fitted to observed data is needed to inform containment strategies. As the transmission of virus varies from city to city in different countries, we use a two-level individual-level model to analyze the spatiotemporal SARS-CoV-2 spread. However, inference procedures such as Bayesian Markov chain Monte Carlo, which is commonly used to estimate parameters of ILMs, are computationally expensive. In this study, we use trained ensemble learning classifiers to estimate the parameters of two-level ILMs and show that the fitted ILMs can successfully capture the virus transmission among Wuhan and 16 other cities in Hubei province, China. © Copyright © 2021 Liu, Deardon, Fu, Ferdous, Ware and Cheng.
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OBJECTIVE: To investigate the risk factors for acute myocardial injury in coronavirus disease 2019 (COVID-19) patients. METHODS: This is a retrospective analysis of a COVID-19 cohort, in which 149 confirmed COVID-19 patients enrolled were divided into the group of myocardial injury (19 cases) and the group of non-myocardial injury (130 cases). Myocardial injury was defined according to Fourth universal definition of myocardial infarction released by European Society of Cardiology (ESC) in 2018, that cardiac troponin (cTn) was above 99th percentile of the reference level. Clinical information and results of laboratory tests of the eligible patients were collected. Factors associated with myocardial injury in COVID-19 patients were evaluated. RESULTS: Compared with the group of non-injury, the patients in the group of injury were older and had a larger proportion of severe or critical cases (P < 0.05), higher respiratory rate and lower percutaneous oxygen saturation (SpO(2)) without oxygen therapy on admission (P < 0.05). All inflammatory indexes except for tumor necrosis factor α (TNF-α) showed significant elevation in the patients of the group of injury (P < 0.05). Analyzed by Spearman correlation test, we showed that the levels of circulatory cTnI were in positive correlation with the levels of high-sensitivity C-reactive protein (hs-CRP), ferritin, receptor of interleukin-2 (IL-2R), interleukin-6 (IL-6) and interleukin-8 (IL-8) (ρ > 0, P < 0.05). Lower SpO(2) without oxygen therapy on admission (OR: 0.860, 95%CI: 0.779-0.949, P=0.003) and higher plasma IL-6 levels (OR: 1.068, 95%CI: 1.019-1.120, P=0.006) were independent risk factors for acute myocardial injury in the patients with COVID-19 by multivariate Logistic regression analyses. CONCLUSION: Hypoxic state and inflammation may play a key role in the pathogenesis of acute myocardial injury in COVID-19 patients.
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The coronaviruses are ssRNA viruses that infect a wide range of mammalian and avian species;they are important causes of respiratory and enteric disease, encephalomyelitis, hepatitis, serositis and vasculitis domestic animals. In humans coronaviruses are one of several groups of viruses that cause the common cold. The genus Coronavirus together with the genus Torovirus from the family Coronaviridae;members of these two genera are similar morphologically. The Coronaviridae, Arteriviridae, and Roniviridae are within the order Nidovirales. Seven coronaviruses are known to infect humans, three of them are serious, namely, SARS (severe acute respiratory syndrome, China, 2002), MERS (Middle East respiratory syndrome, Saudi Arabia, 2012), and SARS-CoV-2 (2019-2020). SARS is caused by a coronavirus (SARS-CoV) which exists in bats and palm civets in Southern China. Its family is Coronaviridae, and its genus is Coronavirus. The most important groups who are at risk are family members in close contact with cases, health-care workers in close contact with cases, elderly and immune compromised individuals appear at increased risk. MERS-CoV is a zoonotic virus which can lead to secondary human infections. It is the sixth coronavirus that influences human. MERS-CoV is most likely derived from an ancestral reservoir bats. MERS outbreak was found in the Republic of Korea since 2015. Coronavirus entry is initiated by the binding of the spike protein (S) to cell receptors, specifically, dipeptidyl peptidase 4 (DDP4) and angiotensin converting enzyme 2 (ACE2) for MERS-CoV and SARS-CoV, respectively. The genome sequence analysis has shown that SARS-CoV-2 belongs to betacoronavirus genus, which includes Bat SARS-like coronavirus, SARS-CoV and MERS-CoV. On the basis of nucleic acid sequence similarity, the newly identified 2019-nCoV is a betacoronavirus. The RBD portion of the SARS-CoV-2 pike proteins has evolved to effectively target a molecular feature on the outside of human cells called ACE2, a receptor involved in regulating blood pressure. The SARS-CoV-2 spike protein was found so effective at binding the human cells. In SARS-CoV-2, M protein is responsible for the transmembrane transport of nutrient, the bud release and the formation of envelope, S protein, attaching to hose receptor ACE2, including two subunits S1 and S2. These diseases can be considered important models for emerging infectious diseases as it emerged from natural animal reservoirs. Early recognition, prompt isolation and appropriate supportive therapy are the main parameters in combating with these deadly infections. © 2020 by Nova Science Publishers, Inc.
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Many herbs and plants included in several traditional systems have promising bioactive compounds for modern drug therapy. The second round of COVID-19 cases will be accompanied by the spread of seasonal influenza in the fall. The combination of the influenza season and the second wave of COVID-19 may lead to more confusion and put more pressure on public health systems. A literature survey was accomplished using multiple databases including PubMed, Science Direct, ISI web of knowledge, and Google Scholar. The most important antiviral herbs for cold and flu are Thymus vulgaris, honeysuckle flowers, Andrographis, yarrow, peppermint leaf and oil, and Calendula. The most important expectorant herbs for flu and cold are tulsi, snake root, licorice root, clove, slippery elm root, marshmallow osha root, and sage leaf. Immunostimulant herbs for these 2 diseases are Echinacea root, Eucalyptus, garlic, ginseng, marshmallow, slippery elm, Isatisroot, Usnea lichen, myrrh resin, and ginger root. In this mini-review, we mention the key role of some of the most important herbal plants and prescriptions against influenza and cold on the basis of traditional Asian medicine.
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The novel coronavirus is a newly discovered pathogen in late December 2019, and its source is currently unknown, which can lead to asymptomatic infection, new coronavirus pneumonia or serious complications, such as acute respiratory failure. Corona virus disease 2019 (COVID-19) is a new type of respiratory disease that is currently spreading all over the world and caused by this coronavirus. Its common symptoms are highly similar to those of other viruses, such as fever, cough and dyspnea. There is currently no vaccine or treatment for COVID-19. Everyone is susceptible to infection with this disease, and owing to the long-term use of immunosuppressants, the immunity of kidney transplant recipients is suppressed, and it is more likely to be infected with the disease. At present, its impact on kidney transplant recipients is unclear. This article reports the clinical features and therapeutic course of novel coronavirus infection in a patient after renal transplantation. A 37-year-old female patient who received a kidney transplant 6 months before was diagnosed with novel coronavirus pneumonia. The patient's symptoms (such as fever, chills, dry cough, muscle aches), laboratory tests (such as decreased white blood cell count, elevated liver enzymes and D-dimer, positive viral nucleic acid test), and chest CT (multiple left lower lung plaque ground glass shadow) were similar to those of non-transplanted novel coronavirus pneumonia patients. In terms of treatment, because the immunity of kidney transplant recipients has been suppressed for a long time, it is a very common strategy to suspend the use of immunosuppressive agents. Therefore, the patient immediately discontinued the immunosuppressive agent after admission, so that she could restore immunity against infection in a short time. At the same time, the use of glucocorticoids was also very important. Its immunosuppressive and anti-inflammatory effects played a large role in the treatment process.In addition, prophylactic antibiotics was needed, and nephrotoxic drugs should be used with caution. Finally, following discounting the use of immunosuppressant and a low-dose glucocorticoid-based treatment regimen, COVID-19 in this renal transplant recipient was successfully cured. The cure of this case was of great significance, and this adjuvant nonspecific antiviral therapy could provide a template for the treatment of other such patients.