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1.
Biomed Opt Express ; 14(3): 1216-1227, 2023 Mar 01.
Article in English | MEDLINE | ID: covidwho-2309102

ABSTRACT

Quantitative detection of virus-like particles under a low concentration is of vital importance for early infection diagnosis and water pollution analysis. In this paper, a novel virus detection method is proposed using indirect polarization parametric imaging method combined with a plasmonic split-ring nanocavity array coated with an Au film and a quantitative algorithm is implemented based on the extended Laplace operator. The attachment of viruses to the split-ring cavity breaks the structural symmetry, and such asymmetry can be enhanced by depositing a thin gold film on the sample, which allows an asymmetrical plasmon mode with a large shift of resonance peak generated under transverse polarization. Correspondingly, the far-field scattering state distribution encoded by the attached virus exhibits a specific asymmetric pattern that is highly correlated to the structural feature of the virus. By utilizing the parametric image sinδ to collect information on the spatial photon state distribution and far-field asymmetry with a sub-wavelength resolution, the appearance of viruses can be detected. To further reduce the background noise and enhance the asymmetric signals, an extended Laplace operator method which divides the detection area into topological units and then calculates the asymmetric parameter is applied, enabling easier determination of virus appearance. Experimental results show that the developed method can provide a detection limit as low as 56 vp/150µL on a large scale, which has great potential in early virus screening and other applications.

2.
Int J Nanomedicine ; 17: 3325-3341, 2022.
Article in English | MEDLINE | ID: covidwho-1968915

ABSTRACT

Purpose: Current vaccines for the SARS-CoV-2 virus mainly induce neutralizing antibodies but overlook the T cell responses. This study aims to generate an exosomal vaccine carrying T cell epitope peptides of SARS-CoV-2 for the induction of CD8+ T cell response. Methods: Thirty-one peptides presented by HLA-A0201 molecule were conjugated to the DMPE-PEG-NHS molecules, and mixed with DSPE-PEG to form the peptide-PEG-lipid micelles, then fused with exosomes to generate the exosomal vaccine, followed by purification using size-exclusion chromatography and validation by Western blotting, liquid nuclear magnetic resonance (NMR) test and transmission electron microscopy. Furthermore, the exosomal vaccine was mixed with Poly (I:C) adjuvant and subcutaneously administered for three times into the hybrid mice of HLA-A0201/DR1 transgenic mice with wild-type mice. Then, the epitope-specific T cell responses were detected by ex vivo ELISPOT assay and intracellular cytokine staining. Results: The exosomal vaccine was purified from the Peak 2 fraction of FPLC and injected into the hybrid mice for three times. The IFN-γ spot forming units and the frequencies of IFN-γ+/CD8+ T cells were 10-82-fold and 13-65-fold, respectively, higher in the exosomal vaccine group compared to the Poly (I:C) control group, without visible organ toxicity. In comparison with the peptides cocktail vaccine generated in our recent work, the exosomal vaccine induced significantly stronger T cell response. Conclusion: Exosomal vaccine loading T cell epitope peptides of SARS-CoV-2 virus was initially generated without pre-modification for both peptides and exosomes, and elicited robust CD8+ T cell response in HLA-A transgenic mice.


Subject(s)
COVID-19 , Vaccines , Animals , CD8-Positive T-Lymphocytes , COVID-19/prevention & control , COVID-19 Vaccines , Epitopes, T-Lymphocyte , Humans , Mice , Mice, Transgenic , Peptides , Poly I-C , SARS-CoV-2
3.
biorxiv; 2022.
Preprint in English | bioRxiv | ID: ppzbmed-10.1101.2022.08.06.503062

ABSTRACT

Non-coding RNA structure and function are essential to understanding various biological processes, such as cell signaling, gene expression, and post-transcriptional regulations. These are all among the core problems in the RNA field. With the rapid growth of sequencing technology, we have accumulated a massive amount of unannotated RNA sequences. On the other hand, expensive experimental observatory results in only limited numbers of annotated data and 3D structures. Hence, it is still challenging to design computational methods for predicting their structures and functions. The lack of annotated data and systematic study causes inferior performance. To resolve the issue, we propose a novel RNA foundation model (RNA-FM) to take advantage of all the 23 million non-coding RNA sequences through self-supervised learning. Within this approach, we discover that the pre-trained RNA-FM could infer sequential and evolutionary information of non-coding RNAs without using any labels. Furthermore, we demonstrate RNA-FM’s effectiveness by applying it to the downstream secondary/3D structure prediction, SARS-CoV-2 genome structure and evolution prediction, protein-RNA binding preference modeling, and gene expression regulation modeling. The comprehensive experiments show that the proposed method improves the RNA structural and functional modelling results significantly and consistently. Despite only being trained with unlabelled data, RNA-FM can serve as the foundational model for the field.

4.
Journal of the Association for Information Science & Technology ; : 1, 2022.
Article in English | Academic Search Complete | ID: covidwho-1898539

ABSTRACT

As a healthcare ICT4D solution, mobile health (mHealth) can potentially improve users' well‐being during pandemics, especially in developing countries with limited healthcare resources. Recent ICT4D research reveals that providing end‐users with access to ICT is insufficient for improving well‐being and, thus, understanding how mHealth empowers end‐users to enhance well‐being against stressful events is important. However, prior research has rarely discussed the issue of empowerment in the domain of mHealth or the context of major disruptive events. This paper contributes to the literature by conceptualizing the psychological empowerment of mHealth users (PEMU) and investigating its nomological network during pandemics. Drawing upon theories of psychological empowerment and event characteristics, we developed a research model and tested it through a mixed‐methods investigation, containing a quantitative study with 602 Chinese mHealth users during COVID‐19 and a follow‐up qualitative study of 326 online articles and reviews. We found that PEMU, driven by three technological characteristics (perceived response efficacy, ease of use, and mHealth quality), affects well‐being through both (a) a stress‐buffering effect, which counterbalances the detrimental, stress‐increasing effects of event criticality and disruption, and (b) a vitality‐stimulating effect, which is intensified by event criticality. These findings have important implications for ICT4D research and practice. [ FROM AUTHOR] Copyright of Journal of the Association for Information Science & Technology 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.)

5.
Lupus ; 31(6): 684-696, 2022 May.
Article in English | MEDLINE | ID: covidwho-1775183

ABSTRACT

The objectives of the study were to review the articles to identify (a) the epidemiology of systemic lupus erythematosus (SLE) and coronavirus disease 2019 (COVID-19); (b) the clinical characteristics of SLE patients with COVID-19; (c) the treatment of COVID-19 in SLE patients; and (d) the impact of COVID-19 pandemic on SLE patients. PubMed was systematically reviewed for literature published from December 2019 to June 2021. Our search was limited to human studies, with language restriction of English. Studies were included if they reported COVID-19 in SLE patients. Our systematic review included 52 studies. The prevalence of COVID-19 infection ranged from 0.0% to 18.1% in SLE patients, and the hospitalisation rates ranged from 0.24% to 10.6%. COVID-19 infection is likely to mimic SLE flare. Hydroxychloroquine (HCQ) was ineffective in prevention of COVID-19, and SLE patients with COVID-19 faced difficulty in healthcare access, had financial constraints and suffered from psychological distress during the pandemic. The pandemic had a significant effect on mental and physical health. Adequate healthcare access, along with containment policies, social distancing measures and psychological nursing was required.


Subject(s)
COVID-19 , Lupus Erythematosus, Systemic , Humans , Hydroxychloroquine/therapeutic use , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/drug therapy , Lupus Erythematosus, Systemic/epidemiology , Pandemics
6.
biorxiv; 2022.
Preprint in English | bioRxiv | ID: ppzbmed-10.1101.2022.01.25.477789

ABSTRACT

The widespread SARS-CoV-2 in humans results in the continuous emergence of new variants. Recently emerged Omicron variant with multiple spike mutations sharply increases the risk of breakthrough infection or reinfection, highlighting the urgent need for new vaccines with broad-spectrum antigenic coverage. Using inter-lineage chimera and mutation patch strategies, we engineered a recombinant monomeric spike variant (STFK1628x), which showed high immunogenicity and mutually complementary antigenicity to its prototypic form (STFK). In hamsters, a bivalent vaccine comprised of STFK and STFK1628x elicited high titers of broad-spectrum antibodies to neutralize all 14 circulating SARS-CoV-2 variants, including Omicron; and fully protected vaccinees from intranasal SARS-CoV-2 challenges of either the ancestral strain or immune-evasive Beta variant. Strikingly, the vaccination of hamsters with the bivalent vaccine completely blocked the within-cage virus transmission to unvaccinated sentinels, for either the ancestral SARS-CoV-2 or Beta variant. Thus, our study provides new insights and antigen candidates for developing next-generation COVID-19 vaccines.


Subject(s)
COVID-19 , Breakthrough Pain
8.
psyarxiv; 2021.
Preprint in English | PREPRINT-PSYARXIV | ID: ppzbmed-10.31234.osf.io.na2qu

ABSTRACT

The provision of higher education has been changing ever more quickly in the UK and worldwide, as a result of technological, economic, and geopolitical factors. The Covid-19 pandemic has accelerated such changes. The “student experience”—the interaction of students with their institution and with each other—has been changing accordingly, with less face-to-face contact. In this work, we have explored a way to improve student engagement in higher education. We describe “ValuED”, a blockchain-based trading platform using a cryptocurrency. It allows students both to buy and sell goods and services within their university community and to be rewarded for academic engagement. ValuED involves a reputation system to further incentivise participants. We describe the implementation and piloting of this platform and draw conclusions for its future use. The platform’s source code is publicly available.


Subject(s)
COVID-19
9.
arxiv; 2021.
Preprint in English | PREPRINT-ARXIV | ID: ppzbmed-2109.07652v2

ABSTRACT

Objectives: To assess self-reported population oral health conditions amid COVID-19 pandemic using user reports on Twitter. Method and Material: We collected oral health-related tweets during the COVID-19 pandemic from 9,104 Twitter users across 26 states (with sufficient samples) in the United States between November 12, 2020 and June 14, 2021. We inferred user demographics by leveraging the visual information from the user profile images. Other characteristics including income, population density, poverty rate, health insurance coverage rate, community water fluoridation rate, and relative change in the number of daily confirmed COVID-19 cases were acquired or inferred based on retrieved information from user profiles. We performed logistic regression to examine whether discussions vary across user characteristics. Results: Overall, 26.70% of the Twitter users discuss wisdom tooth pain/jaw hurt, 23.86% tweet about dental service/cavity, 18.97% discuss chipped tooth/tooth break, 16.23% talk about dental pain, and the rest are about tooth decay/gum bleeding. Women and younger adults (19-29) are more likely to talk about oral health problems. Health insurance coverage rate is the most significant predictor in logistic regression for topic prediction. Conclusion: Tweets inform social disparities in oral health during the pandemic. For instance, people from counties at a higher risk of COVID-19 talk more about tooth decay/gum bleeding and chipped tooth/tooth break. Older adults, who are vulnerable to COVID-19, are more likely to discuss dental pain. Topics of interest vary across user characteristics. Through the lens of social media, our findings may provide insights for oral health practitioners and policy makers.


Subject(s)
COVID-19
10.
researchsquare; 2021.
Preprint in English | PREPRINT-RESEARCHSQUARE | ID: ppzbmed-10.21203.rs.3.rs-468659.v1

ABSTRACT

BackgroundSince December 2019, an infectious disease caused by SARS-CoV-2 has swept through the world and has had a significant impact on dental services. Methods: In this study, from April 21 to April 28, 2020, a questionnaire survey was taken by a self-made questionnaire in order to investigate the impact of the COVID-19 epidemic on the decision-making process for impacted mandibular third molar removal and related clinical teaching. The Wenjuanxing software was used as a survey platform to survey oral clinicians engaged in the extraction of mandibular third molars. ResultsA total of 321 valid questionnaires were returned in this study. Because of the COVID-19 pandemic. The results showed that 22.4% of clinicians were temporarily not performing tooth extractions in outpatient clinics, and 50.2% of clinicians were temporarily not performing impacted tooth extractions. The main reason cited was that “Aerosol-generating high-speed handpieces were not recommended to be used during the pandemic.” During the pandemic, the surgical handpiece with copious saline irrigation was the main method used for bone removal; the hammer-and-chisel method was considered to be too traumatic and posed too high a risk of iatrogenic injury.ConclusionThe implementation of epidemic control measures during the novel COVID-19 pandemic significantly affects clinical decision making regarding impacted mandibular third molar extractions, the main reason cited was the contraindication to using aerosol-generating high-speed handpieces. The hammer and chisel method may represent a valuable surgical application under the requirements for epidemic prevention and control.


Subject(s)
COVID-19
11.
Clin Immunol ; 222: 108642, 2021 01.
Article in English | MEDLINE | ID: covidwho-1064948

ABSTRACT

BACKGROUND: Abnormal peripheral immunological features are associated with the progression of coronavirus disease 2019 (COVID-19). METHODS: Clinical and laboratory data were retrieved in a cohort of 146 laboratory-confirmed COVID-19 patients. Potential risk factors for the development of severe COVID-19 were evaluated. RESULTS: On admission, lymphocytes, CD3+, CD4+ and CD8+ T cells, eosinophils, and albumin and pre-albumin were dramatically lower, whereas neutrophils, and interleukin (IL)-10, C-reactive protein (CRP), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT) were significantly higher in severe cases. By the second week after discharge, all variables improved to normal levels. Covariate logistic regression results showed that the CD8+ cell count and CRP level were independent risk factors for severe COVID-19. CONCLUSION: Lower peripheral immune cell subsets in patients with severe disease recovered to normal levels as early as the second week after discharge. CD8+ T cell counts and CRP levels on admission are independent predictive factors for severe COVID-19.


Subject(s)
COVID-19/epidemiology , COVID-19/immunology , Cytokines/metabolism , SARS-CoV-2 , T-Lymphocytes/classification , T-Lymphocytes/physiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , China/epidemiology , Cytokines/genetics , Eosinophils , Female , Gene Expression Regulation/immunology , Humans , Male , Middle Aged , Retrospective Studies , Risk Factors , Serum Albumin , Severity of Illness Index , Young Adult
16.
Lancet Digit Health ; 2(6): e323-e330, 2020 06.
Article in English | MEDLINE | ID: covidwho-260619

ABSTRACT

Background: The outbreak of COVID-19 has led to international concern. We aimed to establish an effective screening strategy in Shanghai, China, to aid early identification of patients with COVID-19. Methods: We did a multicentre, observational cohort study in fever clinics of 25 hospitals in 16 districts of Shanghai. All patients visiting the clinics within the study period were included. A strategy for COVID-19 screening was presented and then suspected cases were monitored and analysed until they were confirmed as cases or excluded. Logistic regression was used to determine the risk factors of COVID-19. Findings: We enrolled patients visiting fever clinics from Jan 17 to Feb 16, 2020. Among 53 617 patients visiting fever clinics, 1004 (1·9%) were considered as suspected cases, with 188 (0·4% of all patients, 18·7% of suspected cases) eventually diagnosed as confirmed cases. 154 patients with missing data were excluded from the analysis. Exposure history (odds ratio [OR] 4·16, 95% CI 2·74-6·33; p<0·0001), fatigue (OR 1·56, 1·01-2·41; p=0·043), white blood cell count less than 4 × 109 per L (OR 2·44, 1·28-4·64; p=0·0066), lymphocyte count less than 0·8 × 109 per L (OR 1·82, 1·00-3·31; p=0·049), ground glass opacity (OR 1·95, 1·32-2·89; p=0·0009), and having both lungs affected (OR 1·54, 1·04-2·28; p=0·032) were independent risk factors for confirmed COVID-19. Interpretation: The screening strategy was effective for confirming or excluding COVID-19 during the spread of this contagious disease. Relevant independent risk factors identified in this study might be helpful for early recognition of the disease. Funding: National Natural Science Foundation of China.


Subject(s)
COVID-19/diagnosis , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , COVID-19/epidemiology , COVID-19/etiology , COVID-19/pathology , Child , Child, Preschool , China/epidemiology , Female , Fever/etiology , Humans , Infant , Infant, Newborn , Leukocyte Count , Lung/pathology , Male , Middle Aged , Multivariate Analysis , Risk Factors , Young Adult
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