[Preparation and immungenicity of recombinant protein containing intramolecular adjuvant in SARS-CoV-2 RBD domain].

A fusion protein containing a tetanus toxin peptide, a tuftsin peptide and a SARS-CoV-2S protein receptor-binding domain (RBD) was prepared to investigate the effect of intramolecular adjuvant on humoral and cellular immunity of RBD protein. The tetanus toxin peptide, tuftsin peptide and S protein RBD region were connected by a flexible polypeptide, and a recombinant vector was constructed after codon optimization. The recombinant S-TT-tuftsin protein was prepared by prokaryotic expression and purification. BALB/c mice were immunized after mixed with aluminum adjuvant, and the humoral and cellular immune effects were evaluated. The recombinant S-TT-tuftsin protein was expressed as an inclusion body, and was purified by ion exchange chromatography and renaturated by gradient dialysis. The renaturated protein was identified by Dot blotting and reacted with serum of descendants immunized with SARS-CoV-2 subunit vaccine. The results showed that the antibody level reached a plateau after 35 days of immunization, and the serum antibody ELISA titer of mice immunized with recombinant protein containing intramolecular adjuvant was up to 1:66 240, which was significantly higher than that of mice immunized with S-RBD protein (P < 0.05). At the same time, the recombinant protein containing intramolecular adjuvant stimulated mice to produce a stronger lymphocyte proliferation ability. The stimulation index was 4.71±0.15, which was significantly different from that of the S-RBD protein (1.83±0.09) (P < 0.000 1). Intramolecular adjuvant tetanus toxin peptide and tuftsin peptide significantly enhanced the humoral and cellular immune effect of the SARS-CoV-2 S protein RBD domain, which provideda theoretical basis for the development of subunit vaccines for SARS-CoV-2 and other viruses.

Unidirectional Elimination of Hydrogen by a Giant Local Field Saves First- and Last-Mile Performances of Semiconductor Devices.

Hydrogen, the smallest element, easily forms bonds to host/dopant atoms in semiconductors, which strongly passivates the original electronic characteristics and deteriorates the final reliability. Here, we demonstrate a concept of unidirectional elimination of hydrogen from semiconductor wafers as well as electronic chips through a giant local electric field induced by compact chloridions. We reveal an interactive behavior of chloridions, which can rapidly approach and take hydrogen atoms away from the device surface. A universal and simple technique based on a solution-mediated three-electrode system achieves efficient hydrogen elimination from various semiconductor wafers (p-GaN, p-AlGaN, SiC, and AlInP) and also complete light emitting diodes (LEDs). The p-type conductivity and light output efficiency of H-eliminated UVC LEDs have been significantly enhanced, and the lifetime is almost doubled. Moreover, we confirm that under a one-second irradiation of UVC LEDs, bacteria and COVID-19 coronavirus can be completely killed (>99.93%). This technology will accelerate the further development of the semiconductor-based electronic industry.

Disinfection and Electrostatic Recovery of N95 Respirators by Corona Discharge for Safe Reuse.

With the COVID-19 pandemic surging, the demand for masks is challenging, especially in less-developed areas across the world. Billions of used masks are threatening the environment as a new source of plastic pollution. In this paper, corona discharge (CD) was explored as a safe and reliable method for mask reuse to alleviate the situation. CD can disinfect masks and simultaneously restore electrostatic charges to prevent filtration efficiency deterioration. Electric field, ions, and reactive species generated by CD cause DNA damage and protein denaturation to effectively disinfect N95 respirators. Log reduction of 2-3 against Escherichia coli can be easily reached within 7.5 min. Log reduction of up to 6 can be reached after three cycles of treatment with optimized parameters. CD disinfection is a broad spectrum with log reduction >1 against yeast and >2.5 against spores. N95 respirators can be recharged within 30 s of treatment and the charges can be retained at a higher level than brand-new masks for at least 5 days. The filtration efficiency of masks was maintained at ∼95% after 15 cycles of treatment. CD can provide at least 10 cycles of safe reuse with benefits of high safety, affordability, accessibility, and device scalability/portability.

The chemical mechanism of pestilences or Coronavirus disease 2019 (COVID-19)

Around the end of 2019, a new viral species caused large-scale transmissions and infections, discovered in Wuhan (WHO Emergencies Preparedness, Response, 2020) and subsequently around the world (WHO COVID-19 Disease Dashboard, 2020). Symptoms caused include coughing, shortness of breath, and fever. Around 1% to 5% (Worldometer, 2020) of confirmed infections have resulted in deaths, mainly due to severe respiratory failure (CDC, 2020). Genealogical tree studies of the new virus strains have later revealed them to be phylogenetically intimate relatives of the Severe Acute Respiratory Syndrome Coronavirus, namely (SARS-CoV), first identified in 2003 [1]. This new virus has been named SARS-CoV-2 by the International Committee on Taxonomy of Viruses (ICTV) (Gorbalenya et al., 2020) on February 11th, 2020.

The Preventive and Control Recommendations on Patient With Cleft Lip and Palate During COVID-19 Pandemic in Shanghai.

ABSTRACT: As Corona Virus Disease 2019 (COVID-19) has been gradually controlled domestically, various industries began to resume production in an orderly way. Attention should be paid to the disease and population characteristics of patients with cleft lip with/without palate during diagnosis and treatment. This article summarized and provided prevention and control recommendations on management strategies during hospitalization and protective measures of patients and healthcare workers, hoping to minimize the spread of disease and create a relatively safe environment for medical work.

Brief Report: Retrospective Evaluation on the Efficacy of Lopinavir/Ritonavir and Chloroquine to Treat Nonsevere COVID-19 Patients.

BACKGROUND: The effectiveness of lopinavir/ritonavir (LPV/r) and chloroquine treatment for COVID-19 has not been verified. METHODS: We conducted a retrospective study to summarize the clinical practices of nonsevere patients with COVID-19 receiving the standard care, LPV/r or chloroquine in Beijing Ditan Hospital from January 20 to March 26, 2020. The main outcome measurements include the changes of cycle threshold values of open reading frame 1 ab (ORF1ab) and nucleocapsid (N) genes by reverse transcriptase-polymerase chain reaction assay from day 1 to 7 after admission for patients receiving standard care or after treatment being initiated for patients receiving either LPV/r or chloroquine. The proportion of developing severe illness, fever duration and the time from symptom onset to chest computer tomography improvement, and negative conversion of nucleic acid were compared. RESULTS: Of the 129 patients included in the study, 59 received the standard care, 51 received LPV/r, and 19 received chloroquine. The demographics and baseline characteristics were comparable among the 3 groups. The median duration of fever, median time from symptom onset to chest computer tomography improvement, and negative conversion of the nucleic acid were similar among the 3 groups. The median increase in cycle threshold values of N and ORF1ab gene for patients receiving LPV/r or chloroquine or the standard care during the treatment course was 7.0 and 8.5, 8.0, and 7.6, 5.0, and 4.0, respectively. These figures were not found significantly different among the 3 groups. CONCLUSIONS: Antiviral therapy using LPV/r or chloroquine seemed not to improve the prognosis or shorten the clinical course of COVID-19.

Clinical Characteristics and Risk Factors of Acute Respiratory Distress Syndrome (ARDS) in COVID-19 Patients in Beijing, China: A Retrospective Study.

BACKGROUND Coronavirus disease 2019 (COVID-19) is a new infectious disease, and acute respiratory syndrome (ARDS) plays an important role in the process of disease aggravation. The detailed clinical course and risk factors of ARDS have not been well described. MATERIAL AND METHODS We retrospectively investigated the demographic, clinical, and laboratory data of adult confirmed cases of COVID-19 in Beijing Ditan Hospital from Jan 20 to Feb 29, 2020 and compared the differences between ARDS cases and non-ARDS cases. Univariate and multivariate logistic regression methods were employed to explore the risk factors associated with ARDS. RESULTS Of the 130 adult patients enrolled in this study, the median age was 46.5 (34-62) years and 76 (58.5%) were male. ARDS developed in 26 (20.0%) and 1 (0.8%) death occurred. Fever occurred in 114 patients, with a median highest temperature of 38.5 (38-39)°C and median fever duration of 8 (3-11) days. The median time from illness onset to ARDS was 10 (6-13) days, the median time to chest CT improvement was 17 (14-21) days, and median time to negative nucleic acid test result was 27 (17-33) days. Multivariate regression analysis showed increasing odds of ARDS associated with age older than 65 years (OR=4.75, 95% CL1.26-17.89, P=0.021), lymphocyte counts [0.5-1×109/L (OR=8.80, 95% CL 2.22-34.99, P=0.002); <0.5×109/L(OR=36.23, 95% CL 4.63-2083.48, P=0.001)], and temperature peak ≥39.1°C (OR=5.35, 95% CL 1.38-20.76, P=0.015). CONCLUSIONS ARDS tended to occur in the second week of the disease course. Potential risk factors for ARDS were older age (>65 years), lymphopenia (≤1.0×109/L), and temperature peak (≥39.1°C). These findings could help clinicians to predict which patients will have a poor prognosis at an early stage.