An ultrasensitive electrochemiluminescence immunosensor for SARS-CoV-2 nucleocapsid protein detection based on signal amplification strategy of DMSN@QDs

Based on signal amplification strategy of dendritic mesoporous silica nanospheres loaded with CdSe/ZnS quantum dots (DMSN@QDs), an ultrasensitive electrochemiluminescence (ECL) immunosensor with magnetic separation was constructed for the detection of SARS-CoV-2 nucleocapsid protein (NP). DMSN, a mesoporous material with abundant radial pores, large specific surface area and high porosity, can increase the loading capacity of QDs and hinder their aggregation as the nanocarrier. DMSN@QDs with good ECL efficiency were used as signal labels to construct a sandwich immunosensor. The designed ECL immunosensor displayed a good linear relationship for NP concentrations ranging from 0.005 ng mL(-1) to 50 ng mL(-1), with a limit of detection of 3.33 pg mL(-1). The ECL immunosensor was successfully applied to detect NP in human serum samples with satisfactory recovery. This strategy provided a new method for detecting NP and expanded the application field of DMSN.

Practical Recommendations of Peking Union Medical College Hospital for Assessment and Management of COVID-19 in Primary Care (2023).

Following the recent adjustments to coronavirus disease 2019 (COVID-19) prevention and control policies, an increasing number of medical staffs, especially those in primary care facilities are confront-ed with rapid growth of COVID-19 patients. Peking Union Medical College Hospital (PUMCH) has therefore compiled this recommendation for COVID-19 primary care practices based on a patient-centered perspective and following recommendations from domestic and international guidelines as well as the latest Chinese government policies. Further, PUMCH.s conception and compilation of this recommendation strictly adhere to evidence-based, concise and clinically applicable principles of practice. For the critical clinical questions with insufficient medical evidence, the recommendation offers insights on the basis of experience from PUMCH multi-disciplinary expert team and first-line medics.practices. Emphasizing on screening community residents with higher risk of severe illness, implementing early interventions including pharmaceutical treatment, enhan-cing nutritional support and improving sleep quality, we aim to construct a "Household-Community-Hospital" tertiary defense, with the hope of promoting health and reducing severe cases.Copyright © 2023, Peking Union Medical College Hospital. All rights reserved.

An immobilization-based, loop-mediated isothermal amplification device for nucleic acid detection of SARS-CoV-2 N gene

Confronting the global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), simple, fast and specific non-laboratory SARS-CoV-2 diagnostic tests are urgently required. However, the current nucleic acid assays generally rely on the diagnostic laboratory, trained staff and specialized equipment for execution and analysis, presenting clear limitations in the field detection. Here, we describe a portable and reliable immobilization-based loop-mediated isothermal amplification (LAMP) device which is mobile, without the requirement of any complicated instrument and appropriate for high-throughput testing. This device was constructed by utilizing the interaction between a carboxyl-tagged primer and an amino-tagged substrate, and capable of catching the target sequence in SARS-CoV-2 produced via the immobilization-based LAMP. In this study, the immobilization conditions and immobilized primer structure were explored and optimized. With this proposed device, the analysis result can be obtained rapidly in 30 min with excellent specificity, even if the template is extracted from a complex sample containing pharyngeal swab or human blood. In addition, the device can be applied to detect the nucleic acid of SARS-CoV-2 and various other pathogens, showing attractive potential for rapid and high-throughput detection at airports, railway stations, cold-chain transportations, community hospitals and so on. Therefore, we believe that the immobilization-based LAMP device is an advanced approach to developing a portable, specific, low-cost and high-throughput diagnostic platform.

Analysis of COVID-19 Impact on Public Transport Usage based on Smart Card Data-A Regional Case Study in Australia

The outbreak of COVID-19 has made a profound impact on mobility, especially for public transport users. Extensive research has been conducted on the change of travel patterns in major cities where public transport systems have been well developed and heavily used. However, in small cities, the public transport network is relatively sparse, especially in suburban areas, which makes the corresponding travel patterns differ from those in major cities. Therefore, proper investigation of the public transport usage in such small cities is still needed, especially under the COVID-19 impact. This paper aims to reveal the change of public transport users' travel patterns based on a comparative study of public transport usage Pre-COVID and during the COVID-19 period. The Illawarra, a coastal region close to Sydney in Australia is used as a case study. Smart card data is used to reveal relevant changes in both intraregion (in the Illawarra) and inter-region (between the Illawarra and Sydney) travels in consideration of heterogeneous user groups. The results show a significant decrease (around 47%) in public transport ridership by both train and bus. However, compared to intra-region ridership, the inter-region trips by train drop much more (around 62%). Moreover, heterogeneous age group passengers show different changes after the COVID-19 outbreak. The research findings are expected to provide valuable suggestions for policy making and public transport service adjustment when a similar crisis occurs again. © 2022 IEEE.

A review of electrochemical biosensor application in the detection of the SARS-COV-2

With the rapid spread and proliferation of Coronavirus disease 2019 (COVID-19) worldwide, highly pathogenic severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) seriously threatens human life and health. The rapid and accurate abilities to detect SARS-CoV-2 have become the key to prevent and control COVID-19. Electrochemical sensors have shown broad application prospects in biological detection because of the advantages of high sensitivity, specificity, and short time-consuming. This review summarizes the application of electrochemical biosensors in detecting SARS-CoV-2 and discusses prospects for developing direction in this field.

Restaurant Reservation System: Allocating Customers with Space Management Under the Impact of COVID-19

The service industry takes an essential and necessary position in business and provides various types of entertainment to consumers. Restaurant is recognized as one of the most influenced service industries under the COVID-19 impact, consumers who goes to the restaurant are strictly decreased since the preventing from COVID-19. This paper strives to focus on designing a new reservation system help the restaurant manage the space efficiently and maximize the social value. Considering that customers may have incentives to misreport their values, the VCG mechanism is implemented to ensure that each customer takes rational actions. As a result, we expect that such a reservation system with the VCG mechanism applied can allocate customers efficiently and raise the revenue of the restaurant on condition that the proper prevention of COVID-19 contagion. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

A Dynamic Sensitivity Model for Unidirectional Pedestrian Flow With Overtaking Behaviour and Its Application on Social Distancing's Impact During COVID-19

As a common phenomenon, overtaking behaviour is frequently observed on pedestrian flow, which not only reshapes pedestrian flow but also generates adverse impacts on pedestrian safety to some extent. Prior research focused on unidirectional pedestrian modelling, especially with overtaking behaviour, is limited. Moreover, pedestrian behaviour in the context of COVID-19 is rarely investigated. Inspired by the social force model, this paper proposes a dynamic sensitivity model for unidirectional pedestrian flow, which is able to describe the overtaking behaviour and analyse the potential impact of COVID-19 on pedestrian behaviour. In the proposed model, dynamic sensitivity and attention field of pedestrians are introduced to embody the effects of individual characteristics and surrounding environments on pedestrian behaviours. To calibrate the model and evaluate the effects of COVID-19 pandemic on pedestrian dynamics, real-life data collected by video recordings in Nanjing, China is used in this study. The simulation results indicate that the dynamic sensitivity model is able to reflect the variance of the adaptive velocity and route choice of overtaking pedestrians on unidirectional pedestrian flow. Our research findings show that the social distance during COVID-19 is higher than the value under normal conditions, and the majority of pedestrians tend to follow the suggested social distancing rules during COVID-19. Moreover, the overtaking pedestrians violate the suggested social distancing rules more frequently than the rest pedestrians. IEEE

Traffic Density Reduction Caused by City Lockdowns Across the World during the COVID-19 Epidemic: From the View of High-resolution Remote Sensing Imagery

As the COVID-19 epidemic began to worsen in the first months of 2020, stringent lockdown policies were implemented in numerous cities throughout the world to control human transmission and mitigate its spread. Although traffic density reduction inside the city was felt subjectively, there has thus far been no objective and quantitative study of its variation to reflect the intracity population flows and their corresponding relationship with lockdown policy stringency from the view of remote sensing images with the high resolution under 1m. Accordingly, we here provide a quantitative investigation of the traffic density reduction before and after lockdown was implemented in six cities (Wuhan, Milan, Madrid, Paris, New York, and London) around the world heavily affected by the COVID-19 epidemic, which is accomplished by extracting vehicles from the multi-temporal high-resolution remote sensing images. A novel vehicle detection model combining unsupervised vehicle candidate extraction and deep learning identification was specifically proposed for the images with the resolution of 0.5m. Our results indicate that traffic densities were reduced by an average of approximately 50% (and as much as 75.96%) in these six cities following lockdown. The influences on traffic density reduction rates are also highly correlated with policy stringency, with an R

Patient-reported outcomes of breastcancer patients during the COVID-19 outbreak in theepicenter of China: A cross-sectional survey study

Purpose: We aimed to analyze the psychological status of breast cancer (BC) patients in the epicenter of theCOVID-19 pandemic. Patients and Methods: A total of 658 individuals were recruited from multiple breast cancer centers in HubeiProvince. Online questionnaires were conducted and included demographic information, clinical features, and fourpatient-reported outcomes (PROs) scales (GAP-7, PHQ-9, ISI, and IES-R). Multivariable logistic regression analysis was designed to identify potential factors on mental health outcomes. Results: Questionnaires were collected from February 16 to 19, 2020, the peak time point of COVID-19 outbreak inChina. 46.2% of BC patients had to modify planned necessary anticancer treatment during the outbreak. 8.9% and9.3% of patients reported severe anxiety and severe depression, respectively. 20.8% and 4.0% of patients showedsevere distress and insomnia, respectively. Multivariable logistic regression analysis demonstrated poor generalcondition, shorter duration after BC diagnosis, aggressive BC molecular subtypes, and close contact with COVID-19patients as independent factors associated with anxiety. Poor general condition and CVC (central venous catheter)flushing delay were factors independently associated with depression. In terms of insomnia, poor general condition was the only associated independent factor. Poor physical condition and treatment discontinuation were underlyingrisk factors for distress based on multivariable analysis. Conclusion: High rates of anxiety, depression, distress, and insomnia were observed in patients with breast cancerduring the COVID-19 outbreak. Special attention should be paid to the psychological status of breast cancerpatients, especially those with poor general condition, treatment discontinuation, aggressive molecular subtypes, and metastatic breast cancer.

[The keypoints in treatment of the critical coronavirus disease 2019 patient(1)].

COVID-19 has been prevalent in Wuhan and spread rapidly to all of our country. Some cases can develop into ARDS, or even death. We will share the treatment experience of severe COVID-19 with the first-line treatment experience. The best respiratory support mode should be selected, but the timing of intubation and protection during intubation are two difficulties; patients with high level peep and poor effect in prone position can be given ECMO support. For COVID-19 patients with mechanical ventilation, reasonable sedation and analgesia strategies should be formulated; delirium should not be ignored. In addition, there is up regulation of inflammatory factors in patients with severe COVID-19, but the effect of renal replacement therapy needs to be further confirmed by clinical research.

Rapid and visual detection of 2019 novel coronavirus (SARS-CoV-2) by a reverse transcription loop-mediated isothermal amplification assay.

OBJECTIVE: To evaluate a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and compare it with RT-PCR. METHODS: We designed primers specific to the orf1ab and S genes of SARS-CoV-2. Total viral RNA was extracted using the QIAamp Viral RNA Mini Kit. We optimized the RT-LAMP assay, and evaluated it for its sensitivity and specificity of detection using real-time turbidity monitoring and visual observation. RESULTS: The primer sets orf1ab-4 and S-123 amplified the genes in the shortest times, the mean (±SD) times were 18 ± 1.32 min and 20 ± 1.80 min, respectively, and 63°C was the optimum reaction temperature. The sensitivities were 2 × 101 copies and 2 × 102 copies per reaction with primer sets orf1ab-4 and S-123, respectively. This assay showed no cross-reactivity with 60 other respiratory pathogens. To describe the availability of this method in clinical diagnosis, we collected 130 specimens from patients with clinically suspected SARS-CoV-2 infection. Among them, 58 were confirmed to be positive and 72 were negative by RT-LAMP. The sensitivity was 100% (95% CI 92.3%-100%), specificity 100% (95% CI 93.7%-100%). This assay detected SARS-CoV-2 in a mean (±SD) time of 26.28 ± 4.48 min and the results can be identified with visual observation. CONCLUSION: These results demonstrate that we developed a rapid, simple, specific and sensitive RT-LAMP assay for SARS-CoV-2 detection among clinical samples. It will be a powerful tool for SARS-CoV-2 identification, and for monitoring suspected patients, close contacts and high-risk groups.

[The keypoints in treatment of the critical coronavirus disease 2019 patient(2)].

The treatment of critically ill patients with coronavirus disease 2019(COVID-19) faces compelling challenges. In this issue, we'd like to share our first-line treatment experience in treating COVID-19. Hemodynamics need be closely monitored and different types of shock should be distinguished. Vasoconstrictor drugs should be used rationally and alerting of complications is of the same importance. The risk of venous thromboembolism (VTE) needs to be assessed, and effective prevention should be carried out for high-risk patients. It is necessary to consider the possibility of pulmonary thromboembolism (PTE) in patients with sudden onset of oxygenation deterioration, respiratory distress, reduced blood pressure. However, comprehensive analysis of disease state should be taken into the interpretation of abnormally elevated D-Dimer. Nutritional support is the basis of treatment. It's important to establish individual therapy regimens and to evaluate, monitor and adjust dynamically. Under the current epidemic situation, convalescent plasma can only be used empirically, indications need to be strictly screened, the blood transfusion process should be closely monitored and the curative effect should be dynamically evaluated.

[Pharmacotherapeutics for the New Coronavirus Pneumonia].

The New Coronavirus Pneumonia (NCP, also named as COVID-19 by WHO on Feb 11 2020, is now causing a severe public health emergency in China since. The number of diagnosed cases is more than 40,000 until the submission of this manuscript. Coronavirus has caused several epidemic situations world widely, but the present contagious disease caused by 2019 new Coronavirus is unprecedentedly fulminating. The published cohorts of 2019 new Coronavirus (n-Cov) are single-center studies, or retrospective studies. We here share the therapeutic experiences of NCP treatment with literature review. Combination of Ribavirin and Interferon-α is recommended by the 5(th) edition National Health Commission's Regimen (Revised Edition) because of the effect on MERS (Middle East Respiratory Syndrome), and the effectiveness of Lopinavir/Ritonavir and Remdisivir needs to be confirmed by randomized controlled trial (RCT), given the situation of no specific antivirus drug on NCP is unavailable. Systemic glucocorticosteroid is recommended as a short term use (1~2 mg.kg(-1).d(-1), 3~5d ) by the 5(th) edition National Health Commission's Regimen (Revised Edition) yet RCTs are expected to confirm the effectiveness. Inappropriate application of antibiotics should be avoided, especially the combination of broad-spectrum antibiotics, for the NCP is not often complicated with bacterial infection.