The Antiviral Roles of Hydrogen Sulfide by Blocking the Interaction between SARS-CoV-2 and Its Potential Cell Surface Receptors.

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is posing a great threat to the global economy and public health security. Together with the acknowledged angiotensin-converting enzyme 2, glucose-regulated protein 78, transferrin receptor, AXL, kidney injury molecule-1, and neuropilin 1 are also identified as potential receptors to mediate SARS-CoV-2 infection. Therefore, how to inhibit or delay the binding of SARS-CoV-2 with the abovementioned receptors is a key step for the prevention and treatment of COVID-19. As the third gasotransmitter, hydrogen sulfide (H2S) plays an important role in many physiological and pathophysiological processes. Recently, survivors were reported to have significantly higher H2S levels in COVID-19 patients, and mortality was significantly greater among patients with decreased H2S levels. Considering that the beneficial role of H2S against COVID-19 and COVID-19-induced comorbidities and multiorgan damage has been well-examined and reported in some excellent reviews, this review will discuss the recent findings on the potential receptors of SARS-CoV-2 and how H2S modulates the above receptors, in turn blocking SARS-CoV-2 entry into host cells.

A Dialogue-based Information Extraction System for Medical Insurance Assessment (preprint)

In the Chinese medical insurance industry, the assessor's role is essential and requires significant efforts to converse with the claimant. This is a highly professional job that involves many parts, such as identifying personal information, collecting related evidence, and making a final insurance report. Due to the coronavirus (COVID-19) pandemic, the previous offline insurance assessment has to be conducted online. However, for the junior assessor often lacking practical experience, it is not easy to quickly handle such a complex online procedure, yet this is important as the insurance company needs to decide how much compensation the claimant should receive based on the assessor's feedback. In order to promote assessors' work efficiency and speed up the overall procedure, in this paper, we propose a dialogue-based information extraction system that integrates advanced NLP technologies for medical insurance assessment. With the assistance of our system, the average time cost of the procedure is reduced from 55 minutes to 35 minutes, and the total human resources cost is saved 30% compared with the previous offline procedure. Until now, the system has already served thousands of online claim cases.

Failed detection of the full-length genome of SARS-CoV-2 by ultra-deep sequencing from the recovered and discharged patients retested viral PCR positive (preprint)

Over 10 percent of recovered and discharged patients retested positive for SARS-CoV-2, raising a public health concern whether they could be potential origins of infection. In this study, we found that detectable viral genome in discharged patients might only mean the presence of viral fragments, and could hardly form an infection origin for its extremely low concentration.

Development and Evaluation of A CRISPR-based Diagnostic For 2019-novel Coronavirus (preprint)

Background: The recent outbreak of infections by the 2019 novel coronavirus (2019-nCoV), the third zoonotic CoV has raised great public health concern. The demand for rapid and accurate diagnosis of this novel pathogen brought significant clinical and technological challenges. Currently, metagenomic next-generation sequencing (mNGS) and reverse-transcription PCR (RT-PCR) are the most widely used molecular diagnostics. Methods: 2019-nCoV infections were confirmed in 52 specimens by mNGS. Genomic information was analyzed and used for the design and development of an isothermal, CRISPR-based diagnostic for this novel virus. The diagnostic performance of CRISPR-nCoV was assessed and compared across three technology platforms (mNGS, RT-PCR and CRISPR). Results: 2019-nCoVs sequenced in our study were conserved with the Wuhan strain, and shared certain genetic similarity with SARS-CoV. A high degree of variation in the level of viral RNA was observed in clinical specimens. CRISPR-nCoV demonstrated a near single-copy sensitivity and great clinical sensitivity with a shorter turn-around time than RT-PCR. Conclusion: CRISPR-nCoV presents as a promising diagnostic option for the emerging pathogen.

Optimizing diagnostic strategy for novel coronavirus pneumonia, a multi-center study in Eastern China (preprint)

COVID-19 caused by a novel coronavirus SARS-CoV-2 emerged in Wuhan, Hubei province since December 2019, and caused a rapid outbreak throughout China and globally. Cities outside Hubei are also facing great challenge and require implementing of effective and feasible strategy in precision diagnosing novel coronavirus pneumonia (NCP). We described a multicenter prospective study on diagnostic strategy of suspected NCP patients from January 22nd to February 9th, 2020 in Eastern China cities. Nasopharyngeal swabs were collected from the patients. The epidemiological characteristics, clinical symptoms, laboratory assessments, and computed tomographic (CT) scans were obtained. Pathogen screen were performed including RT-PCR, multiplex PCR, rapid flu antigen tests and mNGS. We enrolled 53 suspected NCP patients, among whom 20 were laboratory-confirmed. Fourteen (70%) and 3 (15%) patients were positive for the first and second SARS-CoV-2 RT-PCR test, respectively. All NCP patients were positive for mNGS. Chest CT images and the symptoms of early stage NCP patients were similar to other viral pneumonia patients. We identified 11 of 20 co-infections in NCP cases, including regular respiratory virus, fungi and bacteria synchronously. Genomic analysis showed that 8 of 10 cases had no mutation in virus genome, while 2 cases had only one single mutation in N gene. Our study discovered that a combination of chest CT, SARS-CoV-2 RT-PCR and multi-plex PCR is recommended in regions outside Hubei province. Co-infection of other pathogens with SARS-CoV-2 exists and should be acknowledged. Repeated sampling, change of specimen type or metagenomics sequencing could further facilitate during critical clinical cases.