Aspergillus niger DLFCC-90 rhamnoside hydrolase, a new type of flavonoid glycoside hydrolase

A novel rutin-α-L-rhamnosidase hydrolyzing α-L-rhamnoside of rutin, naringin, and hesperidin was purified and characterized from Aspergillus niger DLFCC-90, and the gene encoding this enzyme, which is highly homologous to the α-amylase gene, was cloned and expressed in Pichia pastoris GS115. The novel enzyme was classified in glycoside-hydrolase (GH) family 13.     

Construction of glycerol synthesis pathway in <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> for bioconversion of glucose into 1,3-propanediol

1,3-Propanediol (1,3-PDO) is an important three-carbon compound widely used in new polyester polymer materials. Natural organisms that can produce 1,3-PDO from glycerol were well studied. However, no natural microorganisms found could directly convert glucose to 1,3-PDO due to its insufficient glycerol synthesis pathway. In this study, two essential glycerol synthesis genes, CgGPD gene (encoding glycerol-3-phosphate dehydrogenase from Candida glycerinogenes) and ScGPP2 gene (encoding glycerol-3-phosphatase from Saccharomyces cerevisiae), were expressed in wild-type Klebsiella pneumoniae, a natural 1,3-PDO producers with reduction pathway for 1,3-PDO synthesis from glycerol. The results of fermentation, key enzyme activities, and metabolites analysis confirmed that recombinant K. pneumoniae now possessed a metabolic pathway capable of converting glucose to 1,3-PDO. The strain could produce 1,3-PDO from glucose with a final titer of 17.27 g/L with 40 g/L glucose in the medium, showing a 1.26-fold increase compared with 30 g/L glucose. Also, adding certain concentrations of glycerol could quickly initiate the 1,3-PDO synthetic pathway and promote the accumulation of 1,3-PDO, which could shorten the fermentation cycle. These results have important implications for further studies involving the use of one strain for bioconversion of glucose to 1,3-PDO.     

Supreme™ laryngeal mask airway use in general Anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study

Background

The Supreme? laryngeal mask airway (SLMA) is a single-use LMA with double lumen design that allows separation of the respiratory and the alimentary tract, hence potentially reducing the gastric volume and risk of aspiration. The purpose of this prospective cohort study is to evaluate the the role of the SLMA as an airway technique for women undergoing category 2 and 3 Cesarean delivery under general anesthesia.

Methods

We recruited 584 parturients who underwent category 2 or 3 Cesarean delivery under general anesthesia, in which 193 parturients underwent category 2 and 391 parturients underwent category 3 Cesarean delivery. The primary outcome was insertion success rate at 1st attempt in SLMA insertion. The secondary outcomes included anaesthetic, obstetric outcomes and maternal side effects associated with airway device.

Results

The 1st attempt insertion success rate was 98.3%, while the overall insertion success rate was 100%. The mean (Standard deviation) time to effective ventilation was 15.6 (4.4) seconds. Orogastric tube insertion was successful at the 1st attempt in all parturients. There was no clinical evidence of aspiration or regurgitation. No episodes of hypoxemia, laryngospasm or bronchospasm were observed intra-operatively. The incidence of complications was low and with good maternal satisfaction reported.

Conclusions

The SLMA could be an alternative effective airway in category 2 and 3 parturients emergency Cesarean Delivery under general anesthesia in a carefully-selected obstetric population.

Trial registration

Clinical Trials Registration: Clinicaltrials.gov Registration NCT02026882. Registered on December 31, 2013.

     

Synthesis and antiviral activity of novel pyrazole derivatives containing oxime esters group

Fourteen title compounds, 1-substituted-5-substitutedphenylthio-4-pyrazolaldoxime ester derivatives 4a-4n, were synthesized from the starting material 1-substitutedphenyl-3-methyl-5-substitutedphenylthio-4-pyrazolaldoximes 3 by treatment with acyl chloride. The synthesized compounds were characterized by physical constants, and the structures of the title compounds were further confirmed by IR, 1H NMR, 13C NMR and elemental analysis. The bioassay results showed that title compounds possessed weak to good anti-TMV bioactivity with 4l showing significant enhancement of disease resistance in tobacco leaves with high affinity for TMV CP.     

Revisiting the stratigraphic position of the Matuyama–Brunhes geomagnetic polarity boundary in Chinese loess

It is commonly accepted that the climate records in Chinese loess can be correlated well with that in marine sediments. However, discrepancies for the stratigraphic position of paleomagnetic polarity reversal boundary seriously restrict an accurate teleconnection between these two archives. For example, the exact stratigraphic position of the whole Matuyama–Brunhes (MB) transitional polarity zone remains uncertain in Chinese loess. In this study, an accurate transitional zone of the MB reversal from the Mangshan profile, southeast margin of the Chinese Loess Plateau (CLP), was statistically determined using multiple subsets of parallel samples. By integrating results from the central CLP, the whole MB transitional zone is consistently located across the pedostratigraphic and climatostratigraphic transitional zones between S8 and L8 over a wide region of the CLP. This conclusion further supports that the paleosol unit S8 should be teleconnected to the marine oxygen isotope stage 19 rather than 21, and thus unambiguously supplies an accurate age control in constructing a new loess time scale.