The c-numerical range of operator products on $${\mathcal {B}}(H)$$

Zhang, Yanfang; Fang, Xiaochun

doi:10.1007/s43037-019-00022-4

Cited by 4 publications

(2 citation statements)

References 21 publications

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“…All samples were run in triplicate in a 25-μL reaction volume containing 2× SUPER SYBR Mix. The PCR was performed in a Bio-Rad CFX96 real-time System (Bio-Rad Biosystems, CA, USA) using the following amplification parameters: 2 Min at 50 • C, 10 Min at 95 • C, and 40 cycles of 15 Sec at 95 • C and 1 Min at 60 • C. Prior to performing the copy number assay, we generated standard curves for the endogenous control gene glyceraldehyde 3-phosphate dehydrogenase (CgGAP) [15] from C. glycerinogenes genomic DNA, using five serial dilutions ranging from approximately 0.1 fg to 10 pg. After data analysis, the Ct number and Rn were exported for statistical analyses [16,17].…”

Section: The Integrated Identification Of the Recombinant Transformantsmentioning

confidence: 99%

Effects of xylitol dehydrogenase (XYL2) on xylose fermentation by engineered Candida glycerinogenes

Zong

Zhang

Zhuge

et al. 2017

Biotech and App Biochem

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Efficient bioconversion of d-xylose into various biochemicals is critical for lignocelluloses application. Candida glycerinogenes, expressing the xylitol dehydrogenase (XYL2) gene, has the ability to produce glycerol from xylose entered into pentose phosphate pathway. In this study, we demonstrate that low expression levels of the XYL2 gene derived from Scheffersomyces stipitis in C. glycerinogenes is a major bottleneck in efficient xylose fermentation. Through a metabolic engineering approach using an integrative expression, XYL2 was identified as an overexpression target for improving xylose metabolism. Two recombinant strains with XYL2 overexpression were constructed to ferment a mixture of glucose and xylose simultaneously in batch fermentation. Compared with C. glycerinogenes (wild type), glycerol production from xylose by C. glycerinogenes (PURGAPX2) and C. glycerinogenes (PURGPDX2) was increased by 94.5% and 103.3%, respectively. It was also found that additional overexpression of XYL2 under the control of strong promoters in a xylose-fermenting strain not only reduced xylitol accumulation but also increased glycerol yields. As the expression levels of XYL2 increased, the glycerol yields gradually improved from 30.6 to 63.3 g/L, whereas the xylitol yields significantly decreased from 38.7 to 19.9 g/L. These results suggest that strong expression of XYL2 is a necessary condition for developing efficient xylose-fermenting strains.

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Section: The Integrated Identification Of the Recombinant Transformantsmentioning

confidence: 99%

Effects of xylitol dehydrogenase (XYL2) on xylose fermentation by engineered Candida glycerinogenes

Zong

Zhang

Zhuge

et al. 2017

Biotech and App Biochem

View full text Add to dashboard Cite

show abstract

“…In [8], Wang et al also used Halmos' two projections theorem to study the containment region of the numerical range of the product of a pair of positive contractions. Zhang and Yu [15] described the numerical range of the operator P + QP. Motivated by these, we consider the numerical range of the parallel sum P : PQ for orthogonal projections P and Q. Te investigation uses in an essential way Halmos' two projections theorem, which is introduced as follows.…”

Section: Introductionmentioning

confidence: 99%