Fast and efficient template-mediated synthesis of genetic variants.

Efficient methods for the generation of specific mutations enable the study of functional variations in natural populations and lead to advances in genetic engineering applications. Here, we present a new approach, mutagenesis by template-guided amplicon assembly (MEGAA), for the rapid construction of kilobase-sized DNA variants. With this method, many mutations can be generated at a time to a DNA template at more than 90% efficiency per target in a predictable manner. We devised a robust and iterative protocol for an open-source laboratory automation robot that enables desktop production and long-read sequencing validation of variants. Using this system, we demonstrated the construction of 31 natural SARS-CoV2 spike gene variants and 10 recoded Escherichia coli genome fragments, with each 4 kb region containing up to 150 mutations. Furthermore, 125 defined combinatorial adeno-associated virus-2 cap gene variants were easily built using the system, which exhibited viral packaging enhancements of up to 10-fold compared with wild type. Thus, the MEGAA platform enables generation of multi-site sequence variants quickly, cheaply, and in a scalable manner for diverse applications in biotechnology.

Photoactive conjugated polymer-based strategy to effectively inactivate RNA viruses

To efficiently combat viral infectious diseases, it is important to develop broadly applicable countermeasures, and efficient antiviral systems can be developed by elaborating the relationship of antiviral efficiency with the interactions between antiviral agents and viruses. In the present study, conjugated polymer (CP)-based photodynamic therapy was used to inhibit RNA virus infections. A severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudotyped virus composed of an SARS-CoV-2 envelope coated with the S protein and luciferase RNA genome was employed to assess antiviral efficiency. Three cationic CPs with different backbone structures, fluorene-co-phenylene (PFP), thiophene (PMNT), and phenylene vinylene (PPV), exhibit different photoinactivation effects. The highly efficient photoinactivation of PPV and PMNT is derived from the complete photodegradation of spike proteins, nucleocapsid proteins and nucleic acids of SARS-CoV-2 after binding to the viral spike proteins. Although PFP showed the highest efficiency in the photodegradation of spike proteins due to its strong binding affinity, ineffective viral inhibition was observed, which occurred because the viral gene was partially damaged under light irradiation and the process of delivering the viral gene to cells received assistance. This work preliminarily reveals the effect of CP-virus interactions on their photoinactivation activity and should be beneficial for further research on the development of highly efficient antiviral PDT agents.In this work, a photodynamic therapy system based on conjugated polymers (CPs) is developed to inhibit the infection of RNA viruses. Three cationic CPs with different backbone structures fluorene-co-phenylene (PFP), thiophene (PMNT), and phenylene vinylene (PPV) exhibit different photoinactivation effects. PPV and PMNT cause effective inactivation of viruses under light irradiation, while SARS-CoV-2 pseudotyped viruses keep infectious after treated by PFP, which is determined by the interactions between CPs with the proteins and gene of viruses. This work preliminarily reveals the effect of CP-virus interactions on their photoinactivation activity and would be beneficial to develop high-efficient antiviral PDT agents.

Improving occupational health for health workers in a pilot hospital by application of the HealthWISE international tool: An interview and observation study in China.

Objective: For a safe and healthy workplace in the health sector, the International Labor Organization (ILO) and the World Health Organization (WHO) jointly developed HealthWISE, an international technical tool that helps health workers (HWs) to identify workplace hazards and apply low-cost solutions. This study sought to gather experiences and lessons from a Chinese pilot hospital for the scale-up application of HealthWISE. Methods: A qualitative study was undertaken at a Chinese public hospital with a ≥5-year application of HealthWISE through in-depth interviews with targeted HWs who participated in the Training-of-Trainer (TOT) workshops, and observations were gathered using evidence from photos and publications, then, thematic analysis was formulated. Results: Driven by motivation, the participants learned from the HealthWISE TOT workshop alongside the favorite and worst parts of it. Positive changes and results of occupational health for HWs occurred after the workshop, the participants trained others and planned to implement HealthWISE within their responsibility. During the COVID-19 Pandemic, the Hospital acted the approaches of protecting the health, safety and well-being of HWs with significant results. Further suggestions on workshop and HealthWISE implementing as well as the national policies were collected. The study indicated the Hospital's experience of leadership and participation, supporting and facilitating, system establishment, and culture creation. The suggestion included keeping staff engaged under a positive safety and health culture, promoting recognition of HealthWISE among public health institutions nationwide, developing online courses for medical colleges, focusing on the alignment among various law systems, and adopting measures under the principle of the hierarchy of occupational hazards controls. Conclusion: This study has demonstrated the systematic improvement of occupational health for HWs by HealthWISE implementation in the Chinese hospital. The valuable experiences and lessons derived here can be shared with other hospitals in China and beyond, especially under the unprecedented challenges of the COVID-19 pandemic, to achieve the goals of safety, health, and well-being for HWs by building a resilient health system.

Alarming antibody evasion properties of rising SARS-CoV-2 BQ and XBB subvariants.

The BQ and XBB subvariants of SARS-CoV-2 Omicron are now rapidly expanding, possibly due to altered antibody evasion properties deriving from their additional spike mutations. Here, we report that neutralization of BQ.1, BQ.1.1, XBB, and XBB.1 by sera from vaccinees and infected persons was markedly impaired, including sera from individuals boosted with a WA1/BA.5 bivalent mRNA vaccine. Titers against BQ and XBB subvariants were lower by 13- to 81-fold and 66- to 155-fold, respectively, far beyond what had been observed to date. Monoclonal antibodies capable of neutralizing the original Omicron variant were largely inactive against these new subvariants, and the responsible individual spike mutations were identified. These subvariants were found to have similar ACE2-binding affinities as their predecessors. Together, our findings indicate that BQ and XBB subvariants present serious threats to current COVID-19 vaccines, render inactive all authorized antibodies, and may have gained dominance in the population because of their advantage in evading antibodies.

Influencing Factors and Improvement Path of Academic Engagement among College Students in the Context of Epidemic Prevention and Control.

OBJECTIVE: The implementation of online teaching in the context of epidemic prevention and control has had an impact on the learning engagement of college students to some extent. This study aims to investigate the mechanisms that influence perceived social support and health behaviors on learning engagement, so as to make college students more focused on their studies by improving their physical and mental health as well as their ability to perceive social support. METHODS: A total of 538 college students from Henan Province, China, were studied using the Perceived Social Support Scale, Health Behavior Scale and Learning Engagement Scale, and the data were analyzed by IBM SPSS Amos 26.0 software (IBM SPSS Inc., Chicago, IL, USA). RESULTS: (1) The level of health behavior among college students was positively correlated with perceived social support ability (ß = 0.289, p < 0.001); both perceived social support and health behaviors predicted college students' learning engagement significantly (ß = 0.200, p < 0.01; ß = 0.406, p < 0.001). (2) College students' perceived social support partially mediated the relationship between health behaviors and learning engagement. CONCLUSION: One of the main ways to improve college students' learning engagement is to improve their health behavior and perceived social support. This study contributes to a better understanding of the relationships between health behaviors and learning engagement, as well as to the development of interventions to improve learning engagement among college students.

Corrigendum: Take a "selfie": Examining how leaders emerge from leader self-awareness, self-leadership, and self-efficacy.

[This corrects the article DOI: 10.3389/fpsyg.2021.635085.].

Antibody evasion properties of SARS-CoV-2 Omicron sublineages.

The identification of the Omicron (B.1.1.529.1 or BA.1) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Botswana in November 20211 immediately caused concern owing to the number of alterations in the spike glycoprotein that could lead to antibody evasion. We2 and others3-6 recently reported results confirming such a concern. Continuing surveillance of the evolution of Omicron has since revealed the rise in prevalence of two sublineages, BA.1 with an R346K alteration (BA.1+R346K, also known as BA.1.1) and B.1.1.529.2 (BA.2), with the latter containing 8 unique spike alterations and lacking 13 spike alterations found in BA.1. Here we extended our studies to include antigenic characterization of these new sublineages. Polyclonal sera from patients infected by wild-type SARS-CoV-2 or recipients of current mRNA vaccines showed a substantial loss in neutralizing activity against both BA.1+R346K and BA.2, with drops comparable to that already reported for BA.1 (refs. 2,3,5,6). These findings indicate that these three sublineages of Omicron are antigenically equidistant from the wild-type SARS-CoV-2 and thus similarly threaten the efficacies of current vaccines. BA.2 also exhibited marked resistance to 17 of 19 neutralizing monoclonal antibodies tested, including S309 (sotrovimab)7, which had retained appreciable activity against BA.1 and BA.1+R346K (refs. 2-4,6). This finding shows that no authorized monoclonal antibody therapy could adequately cover all sublineages of the Omicron variant, except for the recently authorized LY-CoV1404 (bebtelovimab).

Cryo-EM structure of the SARS-CoV-2 Omicron spike.

The recently reported B.1.1.529 Omicron variant of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) includes 34 mutations in the spike protein relative to the Wuhan strain, including 15 mutations in the receptor-binding domain (RBD). Functional studies have shown Omicron to substantially escape the activity of many SARS-CoV-2-neutralizing antibodies. Here, we report a 3.1 Å-resolution cryoelectron microscopy (cryo-EM) structure of the Omicron spike protein ectodomain. The structure depicts a spike that is exclusively in the 1-RBD-up conformation with high mobility of RBD. Many mutations cause steric clashes and/or altered interactions at antibody-binding surfaces, whereas others mediate changes of the spike structure in local regions to interfere with antibody recognition. Overall, the structure of the Omicron spike reveals how mutations alter its conformation and explains its extraordinary ability to evade neutralizing antibodies.

Striking antibody evasion manifested by the Omicron variant of SARS-CoV-2.

The B.1.1.529/Omicron variant of SARS-CoV-2 was only recently detected in southern Africa, but its subsequent spread has been extensive, both regionally and globally1. It is expected to become dominant in the coming weeks2, probably due to enhanced transmissibility. A striking feature of this variant is the large number of spike mutations3 that pose a threat to the efficacy of current COVID-19 vaccines and antibody therapies4. This concern is amplified by the findings of our study. Here we found that B.1.1.529 is markedly resistant to neutralization by serum not only from patients who recovered from COVID-19, but also from individuals who were vaccinated with one of the four widely used COVID-19 vaccines. Even serum from individuals who were vaccinated and received a booster dose of mRNA-based vaccines exhibited substantially diminished neutralizing activity against B.1.1.529. By evaluating a panel of monoclonal antibodies against all known epitope clusters on the spike protein, we noted that the activity of 17 out of the 19 antibodies tested were either abolished or impaired, including ones that are currently authorized or approved for use in patients. Moreover, we also identified four new spike mutations (S371L, N440K, G446S and Q493R) that confer greater antibody resistance on B.1.1.529. The Omicron variant presents a serious threat to many existing COVID-19 vaccines and therapies, compelling the development of new interventions that anticipate the evolutionary trajectory of SARS-CoV-2.

Therapeutic effect of simultaneous intravitreal dexamethasone and aflibercept on diabetic macular edema.

AIMS: To report the effect of simultaneous intravitreal dexamethasone (DEX) and aflibercept for the treatment of diabetic macular edema (DME). METHODS: This retrospective analysis of an open-label, multicenter, consecutive case series included 102 eyes of 81 patients with DME. Patients were selected into two groups. The control group consisted of 50 eyes treated with aflibercept alone, and the combination group consisted of 52 eyes treated with simultaneous DEX implant and aflibercept injection. The primary endpoints were changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from baseline to month 6. The secondary endpoint was the interval of retreatment. RESULTS: Baseline BCVA increased and CRT decreased at 6 months in both groups. Pseudophakic eyes in the combination group exhibited significantly greater BCVA improvement compared with phakic eyes (p = 0.031). Fewer intravitreal treatments were required for eyes treated with combination therapy than for those treated with aflibercept alone (1.56 ± 0.54 vs. 4.04 ± 1.26, p < .0001), with a mean retreatment interval of 3.66 ± 0.69 months. CONCLUSIONS: Simultaneous intravitreal DEX and aflibercept achieved non-inferior improvement of visual and anatomic outcomes compared with aflibercept alone for DME, but exhibited a significantly longer treatment interval and superior visual outcome in pseudophakic eyes. This therapeutic approach is considered a valid strategy for treating DME in the era of COVID-19.

Self-luminescent photodynamic therapy and pathogen detection for infectious diseases.

The importance of detection and treatments of infectious diseases has been stressed to the world by the ongoing COVID-19 pandemic. As a substitution of an external light source, self-luminescent therapeutics featuring in situ light emission aims to address the lack of tissue penetration in conventional photodynamic therapy (PDT). Luminol-based self-luminescent systems are successfully incorporated in PDT and detection of pathogens in infectious diseases. In these systems, luminol/hydrogen peroxide is served as luminescence source which can be activated by horseradish peroxidase (HRP). As a supplement strategy to the HRP-based bioluminescence, electrochemiluminescence (ECL) provided an electric-driven therapeutic solution and demonstrated potential capabilities of wearable healthcare devices with properly constructed transparent flexible hydrogels. Besides the diagnosis of infection and detection of bacteria, fungi and virus in solution or powder samples have been achieved by ATP-derived self-luminescence as the light source. In this inspirational note, we provide an overview on latest progress in the PDT and microbial detection by self-luminescent systems with an emphasis on the bioluminescence and ECL.