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Variants of the severe acute respiratory syndrome coronavirus (SARS-CoV-2) have evolved such that it may be challenging for diagnosis and clinical treatment of the pandemic coronavirus disease-19 (COVID-19). Compared with developed SARS-CoV-2 diagnostic tools recently, aptamers may exhibit some advantages, including high specificity/affinity, longer shelf life (vs. antibodies), and could be easily prepared. Herein an integrated microfluidic system was developed to automatically carry out one novel screening process based on the systematic evolution of ligands by exponential enrichment (SELEX) for screening aptamers specific with SARS-CoV-2. The new screening process started with five rounds of positive selection (with the S1 protein of SARS-CoV-2). In addition, including non-target viruses (influenza A and B), human respiratory tract-related cancer cells (adenocarcinoma human alveolar basal epithelial cells and dysplastic oral keratinocytes), and upper respiratory tract-related infectious bacteria (including methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae), and human saliva were involved to increase the specificity of the screened aptamer during the negative selection. Totally, all 10 rounds could be completed within 20 h. The dissociation constant of the selected aptamer was determined to be 63.0 nM with S1 protein. Limits of detection for Wuhan and Omicron clinical strains were found to be satisfactory for clinical applications (i.e. 4.80 × 10 1 and 1.95 × 10 2 copies/mL, respectively). Moreover, the developed aptamer was verified to be capable of capturing inactivated SARS-CoV-2 viruses, eight SARS-CoV-2 pseudo-viruses, and clinical isolates of SARS-CoV-2 viruses. For high-variable emerging viruses, this developed integrated microfluidic system can be used to rapidly select highly-specific aptamers based on the novel SELEX methods to deal with infectious diseases in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: To ensure the timely diagnosis of emerging infectious diseases, high-tech molecular biotechnology is often used to detect pathogens and has gradually become the gold standard for virological testing. However, beginners and students are often unable to practice their skills due to the higher costs associated with high-level virological testing, the increasing complexity of the equipment, and the limited number of specimens from patients. Therefore, a new training program is necessary to increase training and reduce the risk of test failure., Objective: The aim of the study is to (1) develop and implement a virtual reality (VR) software for simulated and interactive high-level virological testing that can be applied in clinical practice and skills building or training settings and (2) evaluate the VR simulation's effectiveness on reaction, learning, and behavior of the students (trainees)., Methods: Viral nucleic acid tests on a BD MAX instrument were selected for our VR project because it is a high-tech automatic detection system. There was cooperation between teachers of medical technology and biomedical engineering. Medical technology teachers were responsible for designing the lesson plan, and the biomedical engineering personnel developed the VR software. We designed a novel VR teaching software to simulate cognitive learning via various procedure scenarios and interactive models. The VR software contains 2D VR "cognitive test and learning" lessons and 3D VR "practical skills training" lessons. We evaluated students' learning effectiveness pre- and posttraining and then recorded their behavior patterns when answering questions, performing repeated exercises, and engaging in clinical practice., Results: The results showed that the use of the VR software met participants' needs and enhanced their interest in learning. The average posttraining scores of participants exposed to 2D and 3D VR training were significantly higher than participants who were exposed solely to traditional demonstration teaching (P<.001). Behavioral assessments of students pre- and posttraining showed that students exposed to VR-based training to acquire relevant knowledge of advanced virological testing exhibited significantly improved knowledge of specific items posttraining (P<.01). A higher participant score led to fewer attempts when responding to each item in a matching task. Thus, VR can enhance students' understanding of difficult topics., Conclusions: The VR program designed for this study can reduce the costs associated with virological testing training, thus, increasing their accessibility for students and beginners. It can also reduce the risk of viral infections particularly during disease outbreaks (eg, the COVID-19 pandemic) and also enhance students' learning motivation to strengthen their practical skills., (©Huey-Pin Tsai, Che-Wei Lin, Ying-Jun Lin, Chun-Sheng Yeh, Yan-Shen Shan. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 21.06.2023.)

A method using label-free surface enhanced Raman spectroscopy (SERS) based on substrate design is provided for an early detection and differentiation of spike glycoprotein mutation sites in live SARS-CoV-2 variants. Two SERS-active substrates, Au nanocavities (Au NCs) and Au NPs on porous ZrO 2 (Au NPs/pZrO 2 ), were used to identify specific peaks of A.3, Alpha, and Delta variants at different concentrations and demonstrated the ability to provide their SERS spectra with detection limits of 0.1-1.0% (or 10 4-5 copies/mL). Variant identification can be achieved by cross-examining reference spectra and analyzing the substrate-analyte relationship between the suitability of the analyte upon the hotspot(s) formed at high concentrations and the effective detection distance at low concentrations. Mutation sites on the S1 chain of the spike glycoprotein for each variant may be related and distinguishable. This method does not require sample preprocessing and therefore allows for fast screening, which is of high value for more comprehensive and specific studies to distinguish upcoming variants., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jiunn-Der Liao reports financial support was provided by National Science Council of Taiwan. Jiunn-Der Liao reports a relationship with National Science Council of Taiwan that includes: funding grants. Jiunn-Der Liao has patent pending to National Cheng Kung University., (Copyright © 2023 Elsevier B.V. All rights reserved.)

COVID-19, caused by SARS-CoV-2, created a devastating outbreak worldwide and consequently became a global health concern. However, no verifiable, specifically targeted treatment has been devised for COVID-19. Several emerging vaccines have been used, but protection has not been satisfactory. The complex genetic composition and high mutation frequency of SARS-CoV-2 have caused an uncertain vaccine response. Small interfering RNA (siRNA)-based therapy is an efficient strategy to control various infectious diseases employing post-transcriptional gene silencing through the silencing of target complementary mRNA. Here, we designed two highly effective shRNAs targeting the conserved region of RNA-dependent RNA polymerase (RdRP) and spike proteins capable of significant SARS-CoV-2 replication suppression. The efficacy of this approach suggested that the rapid development of an shRNA-based therapeutic strategy might prove to be highly effective in treating COVID-19. However, it needs further clinical trials.

Background: Drug repurposing is a fast and effective way to develop drugs for an emerging disease such as COVID-19. The main challenges of effective drug repurposing are the discoveries of the right therapeutic targets and the right drugs for combating the disease., Methods: Here, we present a systematic repurposing approach, combining Homopharma and hierarchal systems biology networks (HiSBiN), to predict 327 therapeutic targets and 21,233 drug-target interactions of 1,592 FDA drugs for COVID-19. Among these multi-target drugs, eight candidates (along with pimozide and valsartan) were tested and methotrexate was identified to affect 14 therapeutic targets suppressing SARS-CoV-2 entry, viral replication, and COVID-19 pathologies. Through the use of in vitro (EC 50 = 0.4 μM) and in vivo models, we show that methotrexate is able to inhibit COVID-19 via multiple mechanisms., Results: Our in vitro studies illustrate that methotrexate can suppress SARS-CoV-2 entry and replication by targeting furin and DHFR of the host, respectively. Additionally, methotrexate inhibits all four SARS-CoV-2 variants of concern. In a Syrian hamster model for COVID-19, methotrexate reduced virus replication, inflammation in the infected lungs. By analysis of transcriptomic analysis of collected samples from hamster lung, we uncovered that neutrophil infiltration and the pathways of innate immune response, adaptive immune response and thrombosis are modulated in the treated animals., Conclusions: We demonstrate that this systematic repurposing approach is potentially useful to identify pharmaceutical targets, multi-target drugs and regulated pathways for a complex disease. Our findings indicate that methotrexate is established as a promising drug against SARS-CoV-2 variants and can be used to treat lung damage and inflammation in COVID-19, warranting future evaluation in clinical trials., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chen, Chang, Pathak, Tzou, Luo, Hsu, Li, Lee, Chen, Huang, Yang, Hsu, Tsai, Chang, Hsu, Liu, Chin, Lin, Yang, Wu, Lee, Hsu, Liu, Chu, Wang, Wang, Huang, Lin, Hsieh, Wu Lee, Hung and Yang.)

Background: The regional respiratory syncytial virus (RSV) outbreak in southern Taiwan in late 2020 followed the surge of RSV cases in the national surveillance data and displayed distinct clinical features. This study investigated RSV epidemiology in the most recent five years and compared the clinical manifestations of this outbreak with non-outbreak period., Methods: Medical records of RSV-infected children at the National Cheng Kung University Hospital from January 2016 to December 2020 were retrospectively retrieved from hospital-based electronic medical database. Cases of RSV infection were identified by RSV antigen positive and/or RSV isolated from respiratory specimens. The demographic, clinical presentations, and laboratory data were recorded. The RSV isolates in 2020 was sequenced for phylogenetic analysis., Results: Overall, 442 RSV-infected cases were retrieved and 42.1% (186 cases) clustered in late 2020. The 2020 outbreak started in September, peaked in November, and lasted for 3 months. 2020 RSV-infected children were older (2.3 ± 2.2 years vs. 1.0 ± 1.0 years), more likely to be diagnosed with bronchopneumonia (57.5% vs. 31.6%), but also had a lower hospitalization rate, shorter hospital stay, less oxygen use, and less respiratory distress than those in 2016-2019 (all p value < 0.05). The RSV isolates in 2020 belonged to RSV-A subtype ON1 but were phylogenetically distinct from the ON1 strains prevalent in Taiwan previously., Conclusion: The 2020 RSV outbreak was led by the novel RSV-A subtype ON1 variant with clinical manifestations distinct from previous years. Continuous surveillance of new emerging variants of respiratory viruses in the post-pandemic era is warranted., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2022. Published by Elsevier B.V.)

Rapid, sensitive and accurate diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of great need for effective quarantining and treatment. Real-time reverse-transcription polymerase chain reaction requiring thermocyling has been commonly used for diagnosis of SARS-CoV-2 though it may take two to 4 h before lengthy sample pretreatment process and require bulky apparatus and well-trained personnel. Since multiple reverse transcription loop-mediated isothermal amplification (multiple RT-LAMP) process without thermocycling is sensitive, specific and fast, an electromagnetically-driven microfluidic chip (EMC) was developed herein to lyse SARS-CoV-2 viruses, extract their RNAs, and perform qualitative analysis of three marker genes by on-chip multiple RT-LAMP in an automatic format within 82 min at a limit of detection of only ∼5000 copies per reaction (i.e. 200 virus/ μL). This compact EMC may be especially promising for SARS-CoV-2 diagnostics in resource-limited countries., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The COVID-19 pandemic negatively affected the economy and health security on a global scale, causing a drastic change on lifestyle, calling a need to mitigate further transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Surface-enhanced Raman spectroscopy (SERS) has shown great potential in the sensitive and rapid detection of various molecules including viruses, through the identification of characteristic peaks of their outer membrane proteins. Accurate detection can be developed through the synergistic integration effect among SERS-active substrate, the appropriate laser wavelength, and the target analyte. In this study, gold nanocavities (Au NC) and Au nanoparticles upon ZrO 2 nano-bowls (Au NPs/pZrO 2 ) were tested and used as SERS-active substrates in detecting SARS-CoV-2 pseudovirus containing S protein as a surface capsid glycoprotein (SARS-CoV-2 S pseudovirus) and vesicular stomatitis virus G (VSV-G) pseudo-type lentivirus (VSV-G pseudovirus) to demonstrate their virus detection capability. The optimized Au NCs and Au NPs/pZrO 2 substrates were then verified by examining the repetition of measurement, reproducibility, and detection limit. Due to the difference in geometry and composition of the substrates, the characteristic peak-positions of live SARS-CoV-2 S and VSV-G pseudoviruses in the obtained Raman spectra vary, which were also compared with those of inactivated ones. Based on the experimental results, SERS mechanism of each substrate to detect virus is proposed. The formation of hot spots brought by the synergistic integration effect among substrate, analyte, and laser induction may result differences in the obtained SERS spectra., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jiunn-Der Liao reports financial support was provided by Republic of China Ministry of Science and Technology. Jiunn-Der Liao has patent pending to National Cheng Kung University., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The COVID-19 pandemic has caused a significant burden since December 2019 that has negatively impacted the global economy owing to the fact that the SARS-CoV-2 virus is fast-transmitting and highly contagious. Efforts have been taken to minimize the impact through strict screening measures in country borders in order to isolate potential virus carriers. Effective fast-screening methods are thus needed to identify infected individuals. The standard diagnostic methods for screening SARS-CoV-2 virus have always been to perform nucleic acid-based and serological tests. However, with each having drawbacks on producing false results at very early or later stage after symptoms onset, supplementary techniques are needed to back up these tests. Surface-enhanced Raman spectroscopy (SERS) as a detection technique has continuously advanced throughout the years in terms of sensitivity and capability to detect ultralow concentration of analytes ranging from single molecule to pathogens, to present as a highly potential alternative to known sensing methods. SERS technology as a candidate for an alternative and supplementary diagnostic method for the viral envelope of SARS-CoV-2 virus is presented, comparing its pros and cons to the standard methods and what other aspects it could offer that the other methods are not capable of. Factors that contribute to the detection effectivity of SERS is also discussed to show the advantages and limitations of this technique. Despite its promising capabilities, challenges like sources of SARS-CoV-2 virus and its variations, reliable SERS spectra, mass production of SERS-active substrates, and compliance to regulations for wide-scale testing scenario are highlighted., (Copyright © 2021 Elsevier B.V. All rights reserved.)