Conjugated topological cavity-states in one-dimensional photonic systems and bio-sensing applications.

Traditional photonic systems are endowed with brand new properties owing to the addition of topological physics with light. A conjugated topological cavity-states (CTCS) in one-dimensional photonic systems is presented, which has not only robust light transport but also ultra-high performances, such as high quality factor (high-Q) and perfect transmission. This extraordinary CTCS can address the bottleneck of typical topological photonic systems, which can only achieve robust light transport without maintaining high performance. Furthermore, the CTCS is especially suitable for bio-photonic sensing with high resolution requirements. An ultra-sensitivity of 2000 nm/RIU and a high-Q of 109 for detecting the concentration of SARS-CoV-2 S-glycoprotein solution are obtained. Notably, the CTCS not only opens new possibilities for advanced photonics but also paves the way for high performance in topological photonic devices.

Integrated Chinese herbal medicine and Western medicine successfully resolves spontaneous subcutaneous emphysema and pneumomediastinum in a patient with severe COVID-19 in Taiwan: A case report.

CASE: Serious complications of severe coronavirus disease 2019 (COVID-19) include subcutaneous emphysema (SE) and pneumomediastinum, which are complicated to treat with conventional Western medicine. We report how combining Chinese herbal medicine (CHM) with Western medicine quickly resolved a patient's COVID-19-associated pulmonary complications, shortened hospital stay and improved quality of life. CLINICAL FEATURES AND OUTCOME: A 59-year-old male with a history of smoking and tumors was diagnosed with COVID-19 in May 2021. At hospitalization, his oxygen saturation (SpO2) was 80%, he had a continuous severe cough, rapid shallow breathing, spontaneous SE and pneumomediastinum. By Day 4 of hospitalization, his condition was worsening despite standard care, so CHM was added. After 3-5 days, his coughing had lessened and supplementary oxygen therapy was de-escalated. Nine days after starting CHM, the SE had completely resolved and the patient avoided intubation. His WHO OS 10-point Scale score had fallen from 6 to 3 points and the modified Medical Research Council Dyspnea Scale score from 4 to 2 points. He was hospitalized for 19 days. At 1 week post-discharge, the patient could handle most of his daily activities and experienced minor shortness of breath only when performing labor-intensive tasks. At 1 month, his work output was restored to pre-COVID-19 levels. CONCLUSION: CHM combined with standard Western medicine improved pulmonary function, respiratory rate, blood oxygen saturation and shortened the hospital stay of a patient with severe COVID-19 complicated by SE and pneumomediastinum.

A Structural Comparison of SARS-CoV-2 Main Protease and Animal Coronaviral Main Protease Reveals Species-Specific Ligand Binding and Dimerization Mechanism.

Animal coronaviruses (CoVs) have been identified to be the origin of Severe Acute Respiratory Syndrome (SARS)-CoV, Middle East respiratory syndrome (MERS)-CoV, and probably SARS-CoV-2 that cause severe to fatal diseases in humans. Variations of zoonotic coronaviruses pose potential threats to global human beings. To overcome this problem, we focused on the main protease (Mpro), which is an evolutionary conserved viral protein among different coronaviruses. The broad-spectrum anti-coronaviral drug, GC376, was repurposed to target canine coronavirus (CCoV), which causes gastrointestinal infections in dogs. We found that GC376 can efficiently block the protease activity of CCoV Mpro and can thermodynamically stabilize its folding. The structure of CCoV Mpro in complex with GC376 was subsequently determined at 2.75 Å. GC376 reacts with the catalytic residue C144 of CCoV Mpro and forms an (R)- or (S)-configuration of hemithioacetal. A structural comparison of CCoV Mpro and other animal CoV Mpros with SARS-CoV-2 Mpro revealed three important structural determinants in a substrate-binding pocket that dictate entry and release of substrates. As compared with the conserved A141 of the S1 site and P188 of the S4 site in animal coronaviral Mpros, SARS-CoV-2 Mpro contains N142 and Q189 at equivalent positions which are considered to be more catalytically compatible. Furthermore, the conserved loop with residues 46-49 in animal coronaviral Mpros has been replaced by a stable α-helix in SARS-CoV-2 Mpro. In addition, the species-specific dimerization interface also influences the catalytic efficiency of CoV Mpros. Conclusively, the structural information of this study provides mechanistic insights into the ligand binding and dimerization of CoV Mpros among different species.

A Structural Comparison of SARS-CoV-2 Main Protease and Animal Coronaviral Main Protease Reveals Species-Specific Ligand Binding and Dimerization Mechanism

Animal coronaviruses (CoVs) have been identified to be the origin of Severe Acute Respiratory Syndrome (SARS)-CoV, Middle East respiratory syndrome (MERS)-CoV, and probably SARS-CoV-2 that cause severe to fatal diseases in humans. Variations of zoonotic coronaviruses pose potential threats to global human beings. To overcome this problem, we focused on the main protease (Mpro), which is an evolutionary conserved viral protein among different coronaviruses. The broad-spectrum anti-coronaviral drug, GC376, was repurposed to target canine coronavirus (CCoV), which causes gastrointestinal infections in dogs. We found that GC376 can efficiently block the protease activity of CCoV Mpro and can thermodynamically stabilize its folding. The structure of CCoV Mpro in complex with GC376 was subsequently determined at 2.75 Å. GC376 reacts with the catalytic residue C144 of CCoV Mpro and forms an (R)- or (S)-configuration of hemithioacetal. A structural comparison of CCoV Mpro and other animal CoV Mpros with SARS-CoV-2 Mpro revealed three important structural determinants in a substrate-binding pocket that dictate entry and release of substrates. As compared with the conserved A141 of the S1 site and P188 of the S4 site in animal coronaviral Mpros, SARS-CoV-2 Mpro contains N142 and Q189 at equivalent positions which are considered to be more catalytically compatible. Furthermore, the conserved loop with residues 46–49 in animal coronaviral Mpros has been replaced by a stable α-helix in SARS-CoV-2 Mpro. In addition, the species-specific dimerization interface also influences the catalytic efficiency of CoV Mpros. Conclusively, the structural information of this study provides mechanistic insights into the ligand binding and dimerization of CoV Mpros among different species.

The Mediating Effect of Ownership of Psychological Behavior and Tour Leader Experience on Accountability in Order to Explore the Sustainable Business Model of the Tourism Industry

Since 2019, the world has been affected by COVID-19. The tourism industry, in particular, has suffered greatly. For instance, widespread travel restrictions have directly led to unemployment among tourism practitioners, especially tour leaders engaged in leading overseas tour groups. In the current environment, tour companies are limited to training only, and as such have chosen to focus on strengthening three critical areas: the leadership, psychological, and professional skills of their tour operators. This study contributes to the tourism literature by examining the direct and indirect effects of accountability on ownership of organization behavior (OOB) and tour leader personality in the context of the tourism industry, in order to expand the sustainable development of the tourism industry. The definition of OOB is that the psychological influence of the tour leader will affect their behavior, and the psychological consequences of the tour leader will be affected by experience (such as seniority of the team leader or number of tour groups). A structured questionnaire was used to survey tour leaders who hold an international license in Taiwan. The direct mediating influences of competence and having a place (psychological antecedents) on their accountability was confirmed. OOB also partially mediated the direct positive effect of the practice mechanism on their accountability. Our results also confirmed that competence and having a place are important predictors of the practice mechanism, and are better predictors of accountability than OOB. These findings should enhance the organizational design and marketing options available to travel agency businesses, as well as offering guidance to managers attempting to shape and mold their organizational culture and the behaviors of tour leaders associated with the implementation of OOB, in order to improve accountability in the sustainable business model of tourism.