Essential amino acid residues and catalytic mechanism of trans-epoxysuccinate hydrolase for production of meso-tartaric acid.

Objectives: This study aimed to discuss the essential amino acid residues and catalytic mechanism of trans-epoxysuccinate hydrolase from Pseudomonas koreensis for the production of meso-tartaric acid.

Results: The optimum conditions of the enzyme were 45 °C and pH 9.0, respectively.

The Temporal Lagged Relationship Between Meteorological Factors and Scrub Typhus With the Distributed Lag Non-linear Model in Rural Southwest China.

Background: Meteorological factors can affect the emergence of scrub typhus for a period lasting days to weeks after their occurrence. Furthermore, the relationship between meteorological factors and scrub typhus is complicated because of lagged and non-linear patterns. Investigating the lagged correlation patterns between meteorological variables and scrub typhus may promote an understanding of this association and be beneficial for preventing disease outbreaks.

SARS-CoV-2 Seroprevalence and Profiles Among Convalescents in Sichuan Province, China.

To explore and understand the SARS-CoV-2 seroprevalence of convalescents, the association between antibody levels and demographic factors, and the seroepidemiology of convalescents of COVID-19 till March 2021. We recruited 517 voluntary COVID-19 convalescents in Sichuan Province and collected 1,707 serum samples till March 2021. Then we reported the seroprevalence and analyzed the associated factors.

Isolation of Penicillium expansum WH-3 for the production of L(+)-tartaric acid.

The L(+)-form of tartaric acid (L(+)-TA) exists extensively in nature, and is widely used in the food, chemical, textile, building, and pharmaceutical industries (Su et al., 2001). The main method for L(+)-TA production is microbial transformation by cis-epoxysuccinate hydrolase (CESH), which can catalyze the asymmetric hydrolysis of cis-epoxysuccinic acid or its salts to TA or tartrate (Bao et al.

Spatial and temporal clusters of avian influenza a (H7N9) virus in humans across five epidemics in mainland China: an epidemiological study of laboratory-confirmed cases.

Background: Avian influenza A (H7N9) virus was first reported in mainland China in 2013, and alarming in 2016-17 due to the surge across a wide geographic area. Our study aimed to identify and explore the spatial and temporal variation across five epidemics to reinforce the epidemic prevention and control.

Methods: We collected spatial and temporal information about all laboratory-confirmed human cases of A (H7N9) virus infection reported in mainland China covering 2013-17 from the open source.

Isolation of a novel strain Aspergillus niger WH-2 for production of L(+)-tartaric acid under acidic condition.

Objectives: To isolate a novel cis-epoxysuccinate hydrolase (CESH)-producing fungus for production of L( +)-tartaric acid, before this, all strains were selected from bacteria.

Results: A CESH-producing fungus was first isolated from soil and identified as Aspergillus niger WH-2 based on its morphological properties and ITS sequence. The maximum activity of hyphaball and fermentation supernatants was 1278 ± 64 U/g and 5.

The epidemic potential of avian influenza A (H7N9) virus in humans in mainland China: A two-stage risk analysis.

Background: From 2013 to 2017, more than one thousand avian influenza A (H7N9) confirmed cases with hundreds of deaths were reported in mainland China. To identify priorities for epidemic prevention and control, a risk assessing framework for subnational variations is needed to define the epidemic potential of A (H7N9).

Methods: We established a consolidated two-stage framework that outlined the potential epidemic of H7N9 in humans: The Stage 1, index-case potential, used a Boosted Regression Trees model to assess population at risk due to spillover from poultry; the Stage 2, epidemic potential, synthesized the variables upon a framework of the Index for Risk Management to measure epidemic potential based on the probability of hazards and exposure, the vulnerability and coping capacity.