Design of a rapid electrochemical biosensor based on MXene/Pt/C nanocomposite and DNA/RNA hybridization for the detection of COVID-19.

Since the rapid spread of the SARS-CoV-2 (2019), the need for early diagnostic techniques to control this pandemic has been highlighted. Diagnostic methods based on virus replication, such as RT-PCR, are exceedingly time-consuming and expensive. As a result, a rapid and accurate electrochemical test which is both available and cost-effective was designed in this study. MXene nanosheets (Ti3C2Tx) and carbon platinum (Pt/C) were employed to amplify the signal of this biosensor upon hybridization reaction of the DNA probe and the virus's specific oligonucleotide target in the RdRp gene region. By the differential pulse voltammetry (DPV) technique, the calibration curve was obtained for the target with varying concentrations ranging from 1 aM to 100 nM. Due to the increase in the concentration of the oligonucleotide target, the signal of DPV increased with a positive slope and a correlation coefficient of 0.9977. Therefore, at least a limit of detection (LOD) was obtained 0.4 aM. Furthermore, the specificity and sensitivity of the sensors were evaluated with 192 clinical samples with positive and negative RT-PCR tests, which revealed 100% accuracy and sensitivity, 97.87% specificity and limit of quantification (LOQ) of 60 copies/mL. Besides, various matrices such as saliva, nasopharyngeal swabs, and serum were assessed for detecting SARS-CoV-2 infection by the developed biosensor, indicating that this biosensor has the potential to be used for rapid Covid-19 test detection.

Mashhad urban management practices during the COVID-19 pandemic: a qualitative study to identify challenges, current and future measures

This study aims to make a qualitative assessment of the urban management practices in Mashhad, the second largest metropolis of Iran, during the COVID-19 pandemic, and identify challenges, current measures, and future actions. A grounded theory approach has been used. The data was collected using semi-structured interviews, and MAXQDA-12 software was used for the analysis. The results showed that Mashhad urban management practices have faced 11 main obstacles during this pandemic. Current measures and future actions are presented by taking into account the identified obstacles and challenges. The findings can help urban managers to make decisions based on strong evidence. [ FROM AUTHOR] Copyright of Urban Research & Practice is the property of Routledge 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.)

Sensitive and specific clinically diagnosis of SARS-CoV-2 employing a novel biosensor based on boron nitride quantum dots/flower-like gold nanostructures signal amplification.

The sudden increase of the COVID-19 outbreak and its continued growth with mutations in various forms has created a global health crisis as well as devastating social and economic effects over the past two years. In this study, a screen-printed carbon electrode reinforced with boron nitride quantum dots/flower-like gold nanostructures (BNQDs/FGNs/SPCE) and functionalized by highly specific antisense DNA oligonucleotide presents an alternative and promising solution for targeting SARS-CoV-2 RNA without nucleic acid amplification. The platform was tested on 120 SARS-CoV-2 RNA isolated from real clinical samples (60 positive and 60 negative confirmed by conventional RT-PCR method). Based on obtained quantitative results and statistical analysis (box-diagram, cutoff value, receiver operating characteristic curve, and t-test), the biosensor revealed a significant difference between the two positive and negative groups with 100% sensitivity and 100% specificity. To evaluate the quantitation capacity and detection limit of the biosensor for clinical trials, the detection performance of the biosensor for continuously diluted RNA isolated from SARS-CoV-2-confirmed patients was compared to those obtained by RT-PCR, demonstrating that the detection limit of the biosensor is lower than or comparable to that of RT-PCR. The ssDNA/BNQDs/FGNs/SPCE showed negligible cross-reactivity with RNA fragments isolated from Influenza A (IAV) clinical samples and also remained stable for up to 14 days. In conclusion, the fabricated biosensor may serve as a promising tool for point-of-care applications.

SARS-CoV-2 Liability: The Hidden Mystery Behind Its Presentation in Children.

Coronavirus disease 2019 (COVID-19) is now of global concern because of its rapid dissemination across the globe. It is unclear whether COVID-19 is as hazardous as previous coronavirus outbreaks, though there are many overlapping similarities between these viruses. An important similar feature includes the virus's pathogenicity in pediatric populations. Additionally, genetic factors are recognized as important contributors to infectious disease susceptibility. Further understanding of this area can help make sense of the pathogenesis of COVID-19 and the varying clinical spectrums of the disease. The available data suggests that COVID-19 most likely produces mild symptoms in a healthy pediatric population regardless of their age, and recovery appears to occur without serious sequelae in the vast majority. However, the available data regarding the detailed repercussions of COVID-19 in children is very limited. To date, only some theoretical issues could be responsible for the COVID-19 susceptibility in pediatric patients, including a more intact but mature immune system within the respiratory system, possible role of viral interference in pediatric populations that are more often infected with common respiratory viruses, possible role of gut-lung axis, and a respiratory system with different amounts of cellular receptors for COVID-19 virus. Moreover, there is little data available on the genetic risk factors for COVID-19, and future research should aim to cover this gap in knowledge. This chapter aims to summarize the recently published data on the impact of COVID-19 in the pediatric population and to systematically review the available evidence of genetic risk factors for COVID-19.

The Potential Impact of Statins in the Treatment of Patients with COVID-19 Infection.

INTRODUCTION: Statins are cholesterol-lowering drugs that also have anti-inflammatory/ immunomodulatory properties, and have been suggested as an adjunct therapy for COVID-19. METHODS: To investigate the clinical impact of statins as a potential therapeutic approach in the treatment of cases infected with COVID-19, a systematic search was performed using PubMed and Google Scholar databases. To extend the search results, a set of keywords were used as follows: ("corona virus" OR "Covid-19" OR "SARS-Cov-2" OR "Severe Acute Respiratory Syndrome Coronavirus 2" OR coronavirus) AND (Statins), alongside a manual search in Google Scholar search engine. RESULTS: It has also been suggested that statins could influence the entry of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) into cells by altering the expression of the angiotensin-converting enzyme 2 (ACE2) and CD143 receptors. Statins may be beneficial for COVID-19 patients according to its pleiotropic effects, although, from the clinical aspect, these pleiotropic effects of statins may not be as strong as in preclinical phase on COVID-19. A retrospective study showed favorable effects for statins in SARS-CoV-2 infection. CONCLUSION: Patients with SARS-CoV-2 infection have a high risk of cardiovascular and thrombotic complications and pleiotropic effects of statins may help manage the COVID-19. There is growing evidence that supports the need for trials of statin treatment in COVID-19 infection.

The Chance of COVID-19 Infection after Vaccination.

The outbreak of COVID-19 that was first reported in Wuhan, China, has constituted a new emerging epidemic that has spread around the world. There are some reports illustrating the patients getting re-infected after recovering from COVID-19. Here, we provide an overview of the biphasic cycle of COVID-19, genetic diversity, immune response, and a chance of reinfection after recovering from COVID-19. The new generation of COVID-19 is a highly contagious and pathogenic infection that can lead to acute respiratory distress syndrome. Whilst most patients suffer from a mild form of the disease, there is a rising concern that patients who recover from COVID-19 may be at risk of reinfection. The proportion of the infected population is increasing worldwide; meanwhile, the rate and concern of reinfection by the recovered population are still high. Moreover, there is little evidence on the chance of COVID-19 infection even after vaccination, which is around one percent or less. Although the hypothesis of zero reinfections after vaccination has not been clinically proven, further studies should be performed on the recovered class in clusters to study the progression of the exposure with the re-exposed subpopulations to estimate the possibilities of reinfection and, thereby, advocate the use of these antibodies for vaccine creation.

COVID-19 vaccine: where are we now and where should we go?

INTRODUCTION: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has currently caused the pandemic with a high progressive speed and has been considered as the global public health crisis in 2020. This new member of the coronavirus family has created a potentially fatal disease, called coronavirus disease-2019 (COVID-19). Despite the continuous efforts of researchers to find effective vaccines and drugs for COVID-19, there is still no success in this matter. AREAS COVERED: Here, the literature regarding the COVID-19 vaccine candidates currently in the clinical trials, as well as main candidates in pre-clinical stages for development and research, were reviewed. These candidates have been developed under five different major platforms, including live-attenuated vaccine, mRNA-based vaccine, DNA vaccines, inactivated virus, and viral-vector-based vaccine. EXPERT OPINION: There are several limitations in the field of the rapid vaccine development against SARS-CoV-2, and other members of the coronavirus family such as SARS-CoV and MERS-CoV. The key challenges of designing an effective vaccine within a short time include finding the virulence ability of an emerging virus and potential antigen, choosing suitable experimental models and efficient route of administration, the immune-response study, designing the clinical trials, and determining the safety, as well as efficacy.

An effective drug against COVID-19: reality or dream?

Introduction: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is well known as a novel member of the coronavirus family which caused a sudden outbreak of Coronavirus disease-2019 (COVID-19) in China that quickly developed into a global pandemic. No effective approaches are found as yet for the therapy and epidemiological control of this new virus. We searched the literature in PubMed, Scopus, Web of Knowledge, Google Scholar, and MeSH, for articles and abstracts describing SARS-CoV-2, COVID-19, pneumonia, clinical trials, drug, treatment, and medicine.Areas covered: The present study aimed to comprehensively overview the current literature on effective anti-SARS-CoV-2 drugs.Expert opinion: Since the beginning of this pandemic disease, many studies have been conducted to find effective drugs to prevent COVID-19, because there are no specific drugs for the treatment of this disease. Most of these drugs with the antiviral potential effect toward COVID-19 are already used as the treatment of other infectious diseases. Some drugs that show the promising therapeutic potential in the initial clinical studies include remdesivir as an inhibitor of RNA-dependent RNA polymerase and favipiravir as an inhibitor of virus replication. Currently, remdesivir received the FDA authorizes to use as an experimental drug for emergency use in COVID-19 patients.