A5103025430- Microbial bioremediation and biosurfactants
- Enzyme Catalysis and Immobilization
- Microbial Metabolic Engineering and Bioproduction
- Analytical Chemistry and Sensors
- Advanced Chemical Sensor Technologies
- Gas Sensing Nanomaterials and Sensors
- SARS-CoV-2 and COVID-19 Research
- Metal-Catalyzed Oxygenation Mechanisms
- Catalytic Processes in Materials Science
- COVID-19 and Mental Health
- SARS-CoV-2 detection and testing
- COVID-19 epidemiological studies
- Advanced Photocatalysis Techniques
- Microbial metabolism and enzyme function
- Amyloidosis: Diagnosis, Treatment, Outcomes
- Pharmacological Effects and Assays
- Infection Control and Ventilation
- Pesticide and Herbicide Environmental Studies
- Robotic Locomotion and Control
- Analytical Chemistry and Chromatography
- Coordination Chemistry and Organometallics
- Vaccine Coverage and Hesitancy
- Anesthesia and Sedative Agents
- COVID-19 Impact on Reproduction
- Microbial Fuel Cells and Bioremediation
Shanghai Normal University
2022-2024
Peking University
2023
University of Hong Kong
2023
University of Hong Kong - Shenzhen Hospital
2023
Peking University Third Hospital
2023
Beijing Jingshida Electromechanical Equipment Research Institute
2021
Fuzhou University
2020-2021
Zhejiang University of Technology
2020
Guangzhou University
2008-2011
Texas A&M University
2006
COVID-19 mRNA vaccines (Pfizer-BioNTech and Moderna) have been shown to be highly protective against COVID-19-associated hospitalizations (1-3). Data are limited on the level of protection hospitalization among disproportionately affected populations in United States, particularly during periods which B.1.617.2 (Delta) variant SARS-CoV-2, virus that causes COVID-19, predominates (2). U.S. veterans older, more racially diverse, higher prevalences underlying medical conditions than persons...
In 22 participating K–12 schools implementing multiple COVID-19 mitigation strategies, school-based SARS-CoV-2 secondary transmission was detected in two of 102 tested close contacts 37 persons with COVID-19.
ABSTRACT Aromatic hydroxylations are important bacterial metabolic processes but difficult to perform using traditional chemical synthesis, so use a biological catalyst convert the priority pollutant benzene into industrially relevant intermediates, oxidation was investigated. It discovered that toluene 4-monooxygenase (T4MO) of Pseudomonas mendocina KR1, 3-monooxygenase (T3MO) Ralstonia pickettii PKO1, and ortho -monooxygenase (TOM) Burkholderia cepacia G4 phenol, catechol,...
Wild-type toluene 4-monooxygenase (T4MO) of Pseudomonas mendocina KR1 oxidizes to p-cresol (96%) and benzene sequentially phenol, catechol, 1,2,3-trihydroxybenzene. In this study T4MO was found oxidize o-cresol 3-methylcatechol (91%) methylhydroquinone (9%), m-cresol 4-methylcatechol (100%), o-methoxyphenol 4-methoxyresorcinol (87%), 3-methoxycatechol (11%), methoxyhydroquinone (2%). Apparent Vmax values 6.6 +/- 0.9 10.7 0.1 nmol/min/ mg protein were obtained for o-, m-, oxidation by...
A primary goal of protein engineering is to control catalytic activity. Here we show that through mutagenesis three active site residues, the activity a multicomponent monooxygenase altered so it hydroxylates all positions toluene as well both naphthalene. Hence, for first time, an enzyme has been engineered its regiospecific oxidation substrate can be controlled. Through A107G mutation in α-subunit para-monooxygenase, variant was formed hydroxylated primarily at ortho-position while...
Oxygenases are promising biocatalysts for performing selective hydroxylations not accessible by chemical methods. Whereas toluene 4-monooxygenase (T4MO) of Pseudomonas mendocina KR1 hydroxylates monosubstituted benzenes at the para position and ortho-monooxygenase (TOM) Burkholderia cepacia G4 ortho position, 3-monooxygenase (T3MO) Ralstonia pickettii PKO1 was reported previously to hydroxylate meta producing primarily m-cresol (R. H. Olsen, J. Kukor, B. Kaphammer, Bacteriol. 176:3749-3756,...
Abstract After discovering that toluene 4‐monooxygenase (T4MO) of Pseudomonas mendocina KR1 oxidizes nitrobenzene to 4‐nitrocatechol, albeit at a very low rate, this reaction was improved using directed evolution and saturation mutagenesis. Screening 550 colonies from random mutagenesis library generated by error‐prone PCR tmoAB Escherichia coli TG1/pBS(Kan)T4MO on agar plates containing led the discovery nitrocatechol‐producing mutants. One mutant, NB1, contained six amino acid...
Abstract A cataluminescence (CTL) sensor using Y 2 O 3 nanoparticles as the sensing materials was proposed for determination of ethyl acetate. This acetate showed high sensitivity and specificity at optimal temperature 264°C. Quantitative analysis performed a wavelength 425 nm. The linear ranges CTL intensity vs concentrations were 2.0–250 ppm ( r = 0.9965) 250–6500 0.9997) with detection limit (3σ) 0.5 ppm. There no response or weak when foreign substances such formic acid, n ‐hexane,...
Abstract The regiospecific oxidation of the polycyclic aromatic hydrocarbons naphthalene and fluorene was examined with Escherichia coli strains expressing wildtype toluene 4‐monooxygenase (T4MO) from Pseudomonas mendocina KR1, para ‐monooxygenase (TpMO) Ralstonia pickettii PKO1, ortho‐ monooxygenase (TOM) Burkholderia cepacia G4, toluene/ ortho ‐xylene (ToMO) P. stutzeri OX1. T4MO oxidized (12.1 ± 0.8 nmol/min/mg protein at 109 μM), (7.7 1.5 5 mM), (0.68 0.04 0.2 mM) faster than other...
To assess the household secondary infection risk (SIR) of B.1.1.7 (Alpha) and non-Alpha lineages severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children.During January to April 2021, we prospectively followed households with a SARS-CoV-2 infection. We collected questionnaires, serial nasopharyngeal swabs for reverse transcription polymerase chain reaction testing whole genome sequencing, blood samples serology testing. calculated SIRs by primary case age (pediatric vs...
On April 24, 2023, the American Samoa Department of Health (ASDoH) declared a public health emergency amid concern about possible measles outbreak given low 2-dose vaccination coverage at time. ASDoH had received two positive immunoglobulin (Ig) M test results after Flag Day festivities 1 week earlier from vaccinated children. performed active case finding, took actions to mitigate transmission, and requested technical assistance CDC. implemented campaign improve suboptimal coverage....
The solar-powered photocatalytic oxygen reduction reaction is considered a promising alternative method for H2O2 production under mild conditions. However, the intrinsic competitive pathway grossly inhibits selectivity and final yield of accompanying loss photogenerated electrons during process. Herein, two-coordinate nitrogen (N2C) vacancy-rich g-C3N4 (DCN1.2) was developed by polymerization pyrolysis using bottom-up strategy. DCN1.2 with low-coordinated N2C-vacancy enabled an enhanced in...
Households are common places for spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We investigated factors associated with household transmission and acquisition SARS-CoV-2. children age <18 years were enrolled into prospective, longitudinal cohorts followed from August 2020 to 2021 in Utah, September New York City, November October Maryland. Participants self-collected nasal swabs weekly onset illness. Swabs tested SARS-CoV-2 using reverse transcription polymerase...
AbstractWe have recently found that toluene para-monooxygenase (TpMO) of Ralstonia pickettii PKO1 (encoded by tbuA1UBVA2C) performs successive hydroxylations benzene (Appl. Environ. Microbiol. 70: 3814, 2004) as well hydroxylates to a mixture 90% p-cresol and 10% m-cresol which are then further oxidized 100% 4-methylcatechol (J. Bacteriol. 186: 3117, whereas it was thought previously TpMO forms is not capable hydroxylations. Here we propose modification the degradation pathway originally...
Abstract Saturation mutagenesis was used to generate 10 mutants of toluene‐ o ‐xylene monooxygenase (ToMO) at alpha subunit (TouA) positions A101 and A110: A101G, A101I, A101M, A101VE, A101V, A110G, A110C, A110S, A110P, A110T; by testing the substrates toluene, o‐ cresol, m‐ p‐ phenol, naphthalene, methoxyphenol, xylene, nitrobenzene, these were found influence regiospecific oxidation aromatics. For example, compared wild‐type ToMO, TouA variant A101V produced threefold more...
Over 30% of commercial pesticides are racemic mixtures. Nowadays, the environmental safety chiral has received more and attention. Metalaxyl is a broad-spectrum fungicide with systemic function, which carbon. Although its fungicidal activity almost entirely originates from R-enantiomer, enantioselective toxicity metalaxyl in animals human beings not yet clear. In this study, urinary metabolomics approach was applied to analyze changes metabolic phenotypes adolescent rats by using nuclear...
In the present paper, we reported a cataluminescence (CTL) sensor using nanoporous <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> as sensing material to determine trace acetic acid in air. The proposed showed high sensitivity and selectivity at optimal temperature of 293 °C. Quantitative analysis was performed wavelength 440 nm. linear range CTL intensity versus concentration are 25...