Diagnosis and Treatment Strategy of Nasogenic Olfactory Dysfunction.

Since the global outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a symptom of the onset of SARS-CoV-2, olfactory dysfunction (OD), has attracted tremendous attention. OD is not only a negative factor for quality of life but also an independent hazard and early biomarker for various diseases, such as Parkinson's and Huntington's diseases. Therefore, early identification and treatment of OD in patients are critical. Many etiological factors are responsible for OD based on current opinions. Sniffin'Sticks are recommended to identify the initial position (central or peripheral) for OD when treating patients clinically. It is worth emphasizing that the olfactory region in nasal cavity is recognized as the primary and critical olfactory receptor. Many nasal diseases, such as those with traumatic, obstructive and inflammatory causes, can lead to OD. The key question is no refined diagnosis or treatment strategy for nasogenic OD currently. This study summarizes the differences in medical history, symptoms, auxiliary examination, treatment and prognosis of different types of nasogenic OD by analyzing the current studies. We propose using olfactory training after 4-6 weeks of initial treatment for nasogenic OD patients with no significant improvement in olfaction. We hope that our research can provide valuable clinical guidance by systematically summarizing the clinical characteristics of nasogenic OD.

Optimizing two-dose vaccine resource allocation to combat a pandemic in the context of limited supply: The case of COVID-19.

The adequate vaccination is a promising solution to mitigate the enormous socio-economic costs of the ongoing COVID-19 pandemic and allow us to return to normal pre-pandemic activity patterns. However, the vaccine supply shortage will be inevitable during the early stage of the vaccine rollout. Public health authorities face a crucial challenge in allocating scarce vaccines to maximize the benefits of vaccination. In this paper, we study a multi-period two-dose vaccine allocation problem when the vaccine supply is highly limited. To address this problem, we constructed a novel age-structured compartmental model to capture COVID-19 transmission and formulated as a nonlinear programming (NLP) model to minimize the total number of deaths in the population. In the NLP model, we explicitly take into account the two-dose vaccination procedure and several important epidemiologic features of COVID-19, such as pre-symptomatic and asymptomatic transmission, as well as group heterogeneity in susceptibility, symptom rates, severity, etc. We validated the applicability of the proposed model using a real case of the 2021 COVID-19 vaccination campaign in the Midlands of England. We conducted comparative studies to demonstrate the superiority of our method. Our numerical results show that prioritizing the allocation of vaccine resources to older age groups is a robust strategy to prevent more subsequent deaths. In addition, we show that releasing more vaccine doses for first-dose recipients could lead to a greater vaccination benefit than holding back second doses. We also find that it is necessary to maintain appropriate non-pharmaceutical interventions (NPIs) during the vaccination rollout, especially in low-resource settings. Furthermore, our analysis indicates that starting vaccination as soon as possible is able to markedly alleviate the epidemic impact when the vaccine resources are limited but are currently available. Our model provides an effective tool to assist policymakers in developing adaptive COVID-19 likewise vaccination strategies for better preparedness against future pandemic threats.

Transformational Leadership, Organizational Innovation, and ESG Performance: Evidence from SMEs in China

ESG is a sustainable development concept that integrates environmental, social, and corporate governance. Most studies on ESG have been conducted based on secondary data from listed companies and have not used questionnaires as a method for analysis. Given this research gap, this paper examines whether transformational leadership influences ESG performance in SMEs, whether organizational innovation mediates the relationship between transformational leadership and ESG performance, and the moderating effect of external social capital on transformational leadership and organizational innovation. Based on higher-order theory, resource-based theory, stakeholder theory, etc., we tested this hypothesis by conducting a regression analysis with a questionnaire collected from SMEs in China. After controlling for firm ownership, firm size, firm industry, and years in business, the results of the study indicate that transformational leadership has a positive effect on ESG performance and that organizational innovation partially mediates the relationship between transformational leadership and corporate ESG performance. Furthermore, external social capital moderates the direct relationship between transformational leadership and organizational innovation and moderates the role of organizational innovation as a mediator between transformational leadership and ESG performance. This study adds to our further understanding of the relationship between transformational leadership and ESG performance in SMEs, expanding the antecedent research on ESG performance and providing a basis for sustainable SME development.

A SARS-CoV-2 neutralizing antibody discovery by single cell sequencing and molecular modeling.

Although vaccines have been developed, mutations of SARS-CoV-2, especially the dominant B.1.617.2 (delta) and B.1.529 (omicron) strains with more than 30 mutations on their spike protein, have caused a significant decline in prophylaxis, calling for the need for drug improvement. Antibodies are drugs preferentially used in infectious diseases and are easy to get from immunized organisms. The current study combined molecular modeling and single memory B cell sequencing to assess candidate sequences before experiments, providing a strategy for the fabrication of SARS-CoV-2 neutralizing antibodies. A total of 128 sequences were obtained after sequencing 196 memory B cells, and 42 sequences were left after merging extremely similar ones and discarding incomplete ones, followed by homology modeling of the antibody variable region. Thirteen candidate sequences were expressed, of which three were tested positive for receptor binding domain recognition but only one was confirmed as having broad neutralization against several SARS-CoV-2 variants. The current study successfully obtained a SARS-CoV-2 antibody with broad neutralizing abilities and provided a strategy for antibody development in emerging infectious diseases using single memory B cell BCR sequencing and computer assistance in antibody fabrication.

Anti-SARS-CoV-2 spike immunoglobulin G and immunoglobulin M titers decline as interval from the second inactivated vaccine dose to the onset of illness is prolonged in breakthrough infection patients.

BACKGROUND: Understanding of the early immune response in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infections is limited. METHODS: Ninety-eight patients with coronavirus disease 2019 (COVID-19) breakthrough infections were divided into two groups, with intervals from receiving the second dose of inactivated vaccine to the onset of illness <60 or ≥60 days. RESULTS: The median lymphocyte count and the median anti-SARS-CoV-2 spike immunoglobulin G (IgG) and immunoglobulin M (IgM) titers were higher in the <60-day interval group compared with the corresponding medians in the ≥60-day interval group (p = 0.005, p = 0.001, and p = 0.001, respectively). The median interleukin-6 (IL-6) level in the <60-day interval group was significantly lower than the median IL-6 level in the ≥60-day interval group (p < 0.001). CONCLUSIONS: Our results highlight the different anti-SARS-CoV-2 spike IgG and IgM antibody titers among patients with different intervals from receiving the second dose of inactivated vaccine to the onset of illness.

Thorectidiol A Isolated from the Marine Sponge Dactylospongia elegans Disrupts Interactions of the SARS-CoV-2 Spike Receptor Binding Domain with the Host ACE2 Receptor.

Thorectidiols isolated from the marine sponge Dactylospongia elegans (family Thorectidae, order Dictyoceratida) collected in Papua New Guinea are a family of symmetrical and unsymmetrical dimeric biphenyl meroterpenoid stereoisomers presumed to be products of oxidative phenol coupling of a co-occurring racemic monomer, thorectidol (3). One member of the family, thorectidiol A (1), has been isolated in its natural form, and its structure has been elucidated by analysis of NMR, MS, and ECD data. Acetylation of the sponge extract facilitated isolation of additional thorectidiol diacetate stereoisomers and the isolation of the racemic monomer thorectidol acetate (6). Racemic thorectidiol A (1) showed selective inhibition of the SARS-CoV-2 spike receptor binding domain (RBD) interaction with the host ACE2 receptor with an IC50 = 1.0 ± 0.7 µM.

Research on Dual-Technology Fusion Biosensor Chip Based on RNA Virus Medical Detection.

In recent years, the emergence of COVID-19 and other epidemics caused by RNA(ribonucleic acid)-type genetic viruses has aroused the close attention of governments around the world on emergency response to public safety and health emergencies. In this paper, an electrodeless biosensing detection chip for RNA virus medical detection is designed using quartz crystal microbalance technology and local surface plasmon resonance technology. The plasmonic resonance characteristic in the nanostructures of gold nanorods-quartz substrates with different parameters and the surface potential distribution of the quartz crystal microbalance sensing chip were studied by COMSOL finite element simulation software. The results show that the arrangement structure and spacing of gold nanorod dimers greatly affect the local surface plasmon resonance of nanorods, which in turn affects the detection results of biomolecules. Moreover, high concentrations of "hot spots" are distributed between both ends and the gap of the gold nanorod dimer, which reflects the strong hybridization of the multiple resonance modes of the nanoparticles. In addition, by simulating and calculating the surface potential distribution of the electrode area and non-electrode area of the biosensor chip, it was found that the biosensor chip with these two areas can enhance the piezoelectric effect of the quartz chip. Under the same simulation conditions, the biochip with a completely electrodeless structure showed a better sensing performance. The sensor chip combining QCM and LSPR can reduce the influence of the metal electrode on the quartz wafer to improve the sensitivity and accuracy of detection. Considering the significant influence of the gold nanorod dimer plasma resonance mode and the significant advantages of the electrodeless biosensor chip, an electrodeless biosensor combining these two technologies is proposed for RNA virus detection and screening, which has potential applications in biomolecular measurement and other related fields.

One-pot and rapid detection of SARS-CoV-2 viral particles in environment using SERS aptasensor based on a locking amplifier.

With the frequent detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in dwellings and wastewater, the risk of transmission of environmental contaminants is of great concern. Fast, simple and sensitive sensors are essential for timely detecting infection and controlling transmission through environment fomites. Herein, we developed a Surface Enhanced Raman Scattering (SERS) aptasensor, which can realize ultrasensitive and rapid assay of SARS-CoV-2 viral particles. In this strategy, we designed a novel locking amplifier which is activated only in the presence of virus by aptamer recognition. The reaction process was carried out though one-pot method at 37 °C, which can save time and resources. In addition, magnetic beads used in reaction system can simplify operation, as well as provide ideas for developing biosensing robots via magnetic field. This SERS aptasensor can detect SARS-CoV-2 virus with a LOD of 260 TU/µL within 40 min in the linear range of 625-10,000 TU/µL. Therefore, this convenience, speediness, sensitivity, and selectivity of detection has great prospects in analyzing SARS-CoV-2 viral particles or other viruses in environment as well as monitoring of environmental virus sources.

Development and Clinical Applications of a 5-Plex Real-Time RT-PCR for Swine Enteric Coronaviruses.

A PEDV/PDCoV/TGEV/SADS-CoV/XIPC 5-plex real-time RT-PCR was developed and validated for the simultaneous detection and differentiation of four swine enteric coronaviruses (PEDV, PDCoV, TGEV and SADS-CoV) in one PCR reaction (XIPC serves as an exogenous internal positive control). The 5-plex PCR had excellent analytical specificity, analytical sensitivity, and repeatability based on the testing of various viral and bacterial pathogens, serial dilutions of virus isolates, and in vitro transcribed RNAs. The 5-plex PCR had comparable diagnostic performance to a commercial PEDV/TGEV/PDCoV reference PCR, based on the testing of 219 clinical samples. Subsequently, 1807 clinical samples collected from various U.S. states during 2019-2021 were tested by the 5-plex PCR to investigate the presence of SADS-CoV in U.S. swine and the frequency of detecting swine enteric CoVs. All 1807 samples tested negative for SADS-CoV. Among the samples positive for swine enteric CoVs, there was a low frequency of detecting TGEV, an intermediate frequency of detecting PDCoV, and a high frequency of detecting PEDV. Although there is no evidence of SADS-CoV presence in the U.S. at present, the availability of the 5-plex PCR will enable us to conduct ongoing surveillance to detect and differentiate these viruses in swine samples and other host species samples as some of these coronaviruses can cause cross-species infection.

The prevalence and incidence of major depressive disorder in 8079 Chinese university freshmen before and during COVID-19.

BACKGROUND: COVID-19 pandemic may impact the prevalence and incidence of depression in college students. However, there is no longitudinal study focusing on major depressive disorder (MDD) before and during COVID-19 pandemic. METHODS: A cohort study was carried out among 8079 Chinese college freshmen. The baseline survey was conducted in 2018 (T0) and annual follow-ups were in 2019 (T1, before COVID-19) and in 2020 (T2, during COVID-19). CIDI-3.0 was used to diagnose MDD. Random effects logistic models of panel data analysis were used for the risk of MDD incidence. STATA 15.1 was used for all analysis. RESULTS: The weighted 12-month prevalence of MDD at T2 (2.10%) was significantly lower than that at T1 (2.67%) (p < 0.001). However, among students who reported exposure to the COVID-19 events, the annual prevalence of MDD at T2 was higher than that at T1 (4.21% vs. 2.79%, p < 0.001). The incidence from T0 to T1, incidence from T1 to T2, and the 2-year incidence was 2.23%, 1.34% and 3.75%, respectively. Only 8.93% of MDD students had chosen to seek professional help during the COVID-19 pandemic period. LIMITATIONS: The computer assisted CIDI may not be as sensitive and specific as the diagnosis made by a psychiatrist and may have caused report bias. CONCLUSIONS: Although the MDD incidence of college students was decreasing over time, the impact of the pandemic on student mental health may depend on exposure to COVID-19 events. Not seeking professional help in the Chinese college students is still an important issue.

Specific anti-SARS-CoV-2 S1 IgY-scFv is a promising tool for recognition of the virus

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread globally, a series of vaccines, antibodies and drugs have been developed to combat coronavirus disease 2019 (COVID-19). High specific antibodies are powerful tool for the development of immunoassay and providing passive immunotherapy against SARS-CoV-2 and expected with large scale production. SARS-CoV-2 S1 protein was expressed in E. coli BL21 and purified by immobilized metal affinity chromatography, as antigen used to immunize hens, the specific IgY antibodies were extracted form egg yolk by PEG-6000 precipitation, and the titer of anti-S1 IgY antibody reached 1:10,000. IgY single chain variable fragment antibody (IgY-scFv) was generated by using phage display technology and the IgY-scFv showed high binding sensitivity and capacity to S1 protein of SARS-CoV-2, and the minimum detectable antigen S1 protein concentration was 6 ng/µL. The docking study showed that the multiple epitopes on the IgY-scFv interacted with multiple residues on SARS-CoV-2 S1 RBD to form hydrogen bonds. This preliminary study suggests that IgY and IgY-scFv are suitable candidates for the development of immunoassay and passive immunotherapy for COVID-19 to humans and animals.

Evaluation and Influencing Factor Analysis of Sustainable Green Transformation Efficiency of Resource-Based Cities in Western China in the Post-COVID-19 Era.

Under the impact of the coronavirus disease 2019 (COVID-19), green, low-carbon, and sustainable development has become a global consensus, and the world will enter a low-carbon and intelligent production mode faster. As the largest contributor to world economic growth and an active participant in global environmental governance, achieving green recovery and the high-quality economic and social development of China is of great significance to promote the global sustainable development strategy. The green transformation of resource-based cities in Western China is the key factor for China to build a high-quality modern economic system and promote long-term sustainable development. This article used the Super Efficiency Slack Based Model (Super-SBM) model and Malmquist index model of the Data Envelope Analysis (DEA) method to measure the static and dynamic green transformation efficiency of resource-based cities in Western China. It investigated the impact of different factors on the static and dynamic efficiency by constructing panel Tobit and dynamic panel models. The research found that the static efficiency of the green transformation of resource-based cities in Western China is low, and the development is uneven. The dynamic efficiency of green transformation showed a fluctuating upward trend first and an accelerating upward trend later. Different factors have different effects on green transformation efficiency. This article holds that the combination of post-epidemic economic recovery and green transformation is expected to promote the green transformation of western resource-based cities while injecting new vitality into China's green sustainable development in the post-COVID-19 era.

Gender-Specific Related Factors for Suicidal Ideation During COVID-19 Pandemic Lockdown Among 5,175 Chinese Adolescents

Background Suicide was an urgent issue during the pandemic period in adolescents. However, few studies were focused on suicide during the coronavirus disease 2019 (COVID-19) pandemic lockdown. Methods An online survey was conducted among 5,175 Chinese adolescents from June 9th to 29th in 2020 to investigate the prevalence of suicidal ideation (SI) during COVID-19 pandemic lockdown. A gender-specific stepwise logistic regression model was used. All analyses were performed with STATA 15.0. Results About 3% of the participants had reported having SI during the COVID-19 pandemic lockdown period. The prevalence of female SI (3.64%, 95% CI: 2.97–4.45%) was higher than that of males (2.39%, 95% CI: 1.88–3.05%) (χ2 = 6.87, p = 0.009). Quarreling with parents [odds ratio (OR) = 9.73, 95% CI: 5.38–17.59], insomnia (OR = 5.28, 95% CI: 2.81–9.93), previous suicide attempt history (OR = 3.68, 95% CI: 1.69–8.03), previous SI history (OR = 2.81, 95% CI: 1.30–6.06), and feeling depressed during pandemic lockdown (OR = 2.26, 95% CI: 1.22–4.18) were positively associated with the males' SI. However, having emptiness inside (OR = 4.39, 95% CI: 2.19–8.79), quarreling with parents (OR = 3.72, 95% CI: 2.16–6.41), insomnia (OR = 3.28, 95% CI: 1.85–5.80), feeling anxious (OR = 2.62, 95% CI: 1.46–4.70), and longing for father's emotional warmth (OR = 0.38, 0.20–0.72) were associated mostly with females' SI. Conclusions Female adolescents, who felt emptiness from their families and their fathers' emotional warmth, were at much higher risk of having SI during COVID-19 lockdown. We must specify a suicide prevention policy and interventions for adolescents in the pandemic crisis based on gender gaps.

The impact of physical conditions on the incidence of major depressive disorder in Chinese university students: Results from a longitudinal study.

BACKGROUND: Major depressive disorder (MDD) is prevalent, and highly comorbid with physical illnesses. Few longitudinal studies have investigated the relationship between physical health conditions and MDD. The objectives of this study were to investigate the comorbid relationship between physical conditions and MDD, and the association between physical conditions and the 2-year risk of MDD. METHODS: A study was conducted in first-year Chinese university students (n = 8,079) over two and half years, using a longitudinal design. An adapted version of the Composite International Diagnostic Interview (CIDI - 3.0) was used to assess for MDD. The presence of physician diagnosed physical conditions was assessed using ten self-report questions. Cross-sectional and longitudinal associations between self-reported physical conditions and MDD were estimated, adjusting for possible confounders. RESULTS: The most frequently reported physical conditions were migraines, chronic rhinitis, and gastritis. We found that migraines, gastritis, and stomach ulcers were associated with a significantly higher lifetime prevalence of MDD than those without any physical health conditions. In those without a lifetime MDD, migraines, gastritis and stomach ulcers were also found to be significant predictors for 2-year risk of new onset MDD. LIMITATIONS: Recall and selection biases are possible when using self-reporting measures. Additionally, the COVID-19 outbreak impacted the response rate at the second follow-up assessment. Lastly, the severity of the physical conditions was not measured. CONCLUSIONS: Physical conditions and MDD are highly prevalent and comorbid in university students. Migraines, gastritis and stomach ulcers are associated with the risk of developing MDD. Future studies should further investigate how this information can be used to prevent MDD.

The impact of self-efficacy on first onset and prognosis of major depressive disorder: findings from a longitudinal study in a sample of Chinese first-year university students.

BACKGROUND: Self-efficacy is a pivotal factor in the etiology and prognosis of major depression. However, longitudinal studies on the relationship between self-efficacy and major depressive disorder (MDD) are scarce. The objectives were to investigate: (1) the associations between self-efficacy and the 1-year and 2-year risks of first onset of MDD and (2) the associations between self-efficacy and the 1-year and 2-year risks of the persistence/recurrence of MDD, in a sample of first-year university students. METHODS: We followed 8079 first-year university students for 2 years from April 2018 to October 2020. MDD was ascertained by the Chinese version of the Composite International Diagnostic Interview (CIDI-3.0) based on self-report. Self-efficacy was measured by the 10-item General Self-efficacy (GSE) scale. Random effect logistic regression modeling was used to estimate the associations. RESULTS: Among participants without a lifetime MDD, the data showed that participants with high baseline GSE scores were associated with a higher risk of first onset of MDD over 2 years [odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01-1.08]. Among those with a lifetime MDD, participants with high baseline GSE scores were less likely to have had a MDD over 2 years (OR 0.93, 95% CI 0.88-0.99) compared to others. CONCLUSIONS: A high level of GSE may be protective of the risk of persistent or recurrent MDD. More longitudinal studies in university students are needed to further investigate the impact of GSE on the first onset of MDD.

Cinobufacini Improves the Respiratory Function of Severe COVID-19 Patients

Targeted therapeutics for SARS-CoV-2 virus caused COVID-19 are in urgent need. Cinobufacini has been reported to have broad-spectrum antiviral effects and widely used in Southeast Asian countries. This study aims to assess the efficacy of Cinobufacini injection in treating patients with severe COVID-19. A randomized preliminary clinical trial was conducted and eligible patients were allocated to receive general treatment plus Cinobufacini injection or only general treatment as control for 7 days. The primary outcomes of the oxygenation index PaO2/FiO2 and ROX, secondary outcomes of white blood cell count, respiratory support step-down time (RSST), safety indicators, etc were monitored. After 7 days of treatment, the oxygenation index was improved in 95.2% patients in the treatment group compared with 68.4% in the control group. The PaO2/FiO2 and ROX indices in the treatment group (mean, 226.27±67.35 and 14.01±3.99 respectively) were significantly higher than the control group (mean, 143.23±51.29 and 9.64±5.54 respectively). The RSST was 1 day shorter in the treatment group. Multivariate regression analysis suggested that Cinobufacini injection contributed the most to the outcome of PaO2/FiO2. No obvious adverse effects were observed. The preliminary data showed that Cinobufacini injection had apparent efficacy in improving the respiratory function of patients with severe COVID-19.

Arbitrary Scale Super-Resolution for Medical Images.

Single image super-resolution (SISR) aims to obtain a high-resolution output from one low-resolution image. Currently, deep learning-based SISR approaches have been widely discussed in medical image processing, because of their potential to achieve high-quality, high spatial resolution images without the cost of additional scans. However, most existing methods are designed for scale-specific SR tasks and are unable to generalize over magnification scales. In this paper, we propose an approach for medical image arbitrary-scale super-resolution (MIASSR), in which we couple meta-learning with generative adversarial networks (GANs) to super-resolve medical images at any scale of magnification in [Formula: see text]. Compared to state-of-the-art SISR algorithms on single-modal magnetic resonance (MR) brain images (OASIS-brains) and multi-modal MR brain images (BraTS), MIASSR achieves comparable fidelity performance and the best perceptual quality with the smallest model size. We also employ transfer learning to enable MIASSR to tackle SR tasks of new medical modalities, such as cardiac MR images (ACDC) and chest computed tomography images (COVID-CT). The source code of our work is also public. Thus, MIASSR has the potential to become a new foundational pre-/post-processing step in clinical image analysis tasks such as reconstruction, image quality enhancement, and segmentation.

Immunoassay of SARS-CoV-2 nucleocapsid proteins using novel red emission-enhanced carbon dot-based silica spheres.

It is imminent to develop a new type of rapid COVID-19 detection method with high sensitivity. Here, we used novel red emission-enhanced carbon dot (CD)-based silica (RCS) spheres as the signals of lateral flow immunochromatography (LFI) to ultrasensitively detect novel severe acute respiratory syndrome coronavirus 2 nucleocapsid proteins (SARS-CoV-2 NPs). The red emission of CDs can be enhanced and enriched in silica spheres by a simple way. The amino ends of the N-ß-(aminoethyl)-γ-aminopropyltrimethoxy anchor carboxyl-rich CDs and enhance the red emission, while the other end is embedded in the silica carrier. Then, the composite silica spheres werecoated with 3-(triethylsilyl) propylamine to protect the CDs, promote bioconjugation and obtain RCS spheres. The optimal emission peaks of the aqueous solution and the solid state of RCS spheres were at 634 nm and 638 nm, respectively, with quantum yields (QYs) of 48.5% and 35.7%, respectively. Their red emission has a wide excitation range (from the ultraviolet region to the red region), and the best excitation wavelength is about 580 nm. Two fluorescence detection modes of the RCS-LFI technology for the SARS-CoV-2 NP assay are available: the simple mode of observation under ultraviolet light has a sensitivity of 100 pg mL-1; the advanced mode of detection under a fluorescence microscope has a sensitivity of 10 pg mL-1. This assay also exhibits the advantages of fast detection speed, high specificity, and simple operation. In addition, the feasibility of this method in actual sample detection was verified in human serum by the standard-addition method, and the results show that the method has excellent practicability. We believe that this method will be a valuable supplement for the diagnosis of COVID-19.

The point-of-care-testing of nucleic acids by chip, cartridge and paper sensors

ABSTRACT Point-of-care nucleic acid testing (POCNAT) has played an important role in the outbreak of infectious diseases (e.g., COVID-19) over recent years. POCNAT aims to realize the rapid, simple and automatic detection of nucleic acid. Thanks to the development of manufacturing technology, electronic information technology, artificial intelligence technology, and biological information technology in recent years, the development of the POCNAT device has led to significant advancement. Instead of the normal nucleic acid detection methods used in the laboratory, some novel experimental carriers have been applied, such as chips, cartridges and papers. The application of these experimental carriers has realized the automation and integration of nucleic acid detection. The entire process of nucleic acid detection is normally divided into three steps (nucleic acid extraction, target amplification and signal detection). All of the reagents required by the process can be pre-stored on these experimental carriers, without unnecessary manual operation. Furthermore, all of the processes are carried out in this experimental carrier, with the assistance of a specific control device. Although they are complicated to manufacture and precise in design, their application provides a significant step forwards in nucleic acid detection and realizes the integration of nucleic acid detection. This technology has great potential in the field of point-of-care molecular diagnostics in the future. This paper focuses on the relevant content of these experimental carriers.

Early Detection of Severe Acute Respiratory Syndrome Coronavirus 2 Antibodies as a Serologic Marker of Infection in Patients With Coronavirus Disease 2019.

BACKGROUND: Thousands of medical staff have been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with hundreds of deaths reported. Such loss could be prevented if there were a serologic assay for SARS-CoV-2-specific antibodies for serological surveillance of its infection at the early stage of disease. METHODS: Using Chinese hamster ovarian (CHO) cell-expressed full-length SARS-CoV-2 S1 protein as capturing antigen, a coronavirus disease 2019 (COVID-19)/SARS-CoV-2 S1 serology enzyme-linked immunosorbent assay (ELISA) kit was developed and validated with negative samples collected prior to the outbreak or during the outbreak and positive samples from patients confirmed with COVID-19. RESULTS: The specificity of the ELISA kit was 97.5%, as examined against total 412 normal human samples. The sensitivity was 97.1% by testing against 69 samples from hospitalized and/or recovered COVID-19 patients. The overall accuracy rate reached 97.3%. The assay was able to detect SARS-CoV-2 antibody on day 1 after the onset of COVID-19 disease. The average antibody levels increased during hospitalization and 14 days after discharge. SARS-CoV-2 antibodies were detected in 28 of 276 asymptomatic medical staff and 1 of 5 nucleic acid test-negative "close contacts" of COVID-19 patients. CONCLUSIONS: With the assays developed here, we can screen medical staff, incoming patients, passengers, and people who are in close contact with the confirmed patients to identify the "innocent viral spreaders," protect the medical staff, and stop further spread of the virus.