Imaging the Enzymatic Reaction of Urease Using Liquid Crystal-Based pH Sensor

Hu, Qiong-Zheng,Jang, Chang-Hyun Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.12

In this study, real-time and label-free methods for monitoring the enzymatic reaction of urease, which releases ammonia through the hydrolysis of urea in an aqueous solution, were developed using a liquid crystal (LC)-based pH sensor. Nematic liquid crystal 4-cyano-4'-pentylbiphenyl (5CB), doped with 4'-pentyl-biphenyl-4-carboxylic acid (PBA), exhibited a shift in optical appearance from bright to dark when it was in contact with ammonia generated from the enzymatic reaction between urease and urea. This optical change was attributed to the anchoring transitions of LCs caused by hydrophobic interactions between the tails of deprotonted PBA ($PBA^-$) molecules and the LCs at the aqueous/LC interface. This novel technique holds great promise for the sensitive detection of urease along with its substrates and inhibitors.

ON UNICITY OF MEROMORPHIC SOLUTIONS OF DIFFERENTIAL-DIFFERENCE EQUATIONS

Hu, Pei-Chu,Wang, Qiong-Yan Korean Mathematical Society 2018 대한수학회지 Vol.55 No.4

In this paper, we give a uniqueness theorem on meromorphic solutions f of finite order of a class of differential-difference equations such that solutions f are uniquely determined by their poles and two distinct values.

Encoding of XML Elements for Mining Association Rules

Hu Gongzhu,Liu Yan,Huang Qiong Korea Association of Information Systems 2005 情報시스템硏究 Vol.14 No.3

Mining of association rules is to find associations among data items that appear together in some transactions or business activities. As of today, algorithms for association rule mining, as well as for other data mining tasks, are mostly applied to relational databases. As XML being adopted as the universal format for data storage and exchange, mining associations from XML data becomes an area of attention for researchers and developers. The challenge is that the semi-structured data format in XML is not directly suitable for traditional data mining algorithms and tools. In this paper we present an encoding method to encode XML tree-nodes. This method is used to store the XML data in Value Table and Transaction Table that can be easily accessed via indexing. The hierarchical relationship in the original XML tree structure is embedded in the encoding. We applied this method to association rules mining of XML data that may have missing data.

Cardioprotective effect of ginsenoside Rb1 via regulating metabolomics profiling and AMP-activated protein kinase-dependent mitophagy

Jingui Hu,Ling Zhang,Fei Fu,Qiong Lai,Lu Zhang,Tao Liu,Boyang Yu,Junping Kou,Fang Li 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.2

Background: Ginsenoside Rb1, a bioactive component isolated from the Panax ginseng, acts as a remedy to prevent myocardial injury. However, it is obscure whether the cardioprotective functions of Rb1 are related to the regulation of endogenous metabolites, and its potential molecular mechanism still needs further clarification, especially from a comprehensive metabolomics profiling perspective. Methods: The mice model of acute myocardial ischemia (AMI) and oxygen glucose deprivation (OGD)-induced cardiomyocytes injury were applied to explore the protective effect and mechanism of Rb1. Meanwhile, the comprehensive metabolomics profiling was conducted by high-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (HPLC-Q/TOF-MS) and a tandem liquid chromatography and mass spectrometry (LC-MS). Results: Rb1 treatment profoundly reduced the infarct size and attenuated myocardial injury. The metabolic network map of 65 differential endogenous metabolites was constructed and provided a new inspiration for the treatment of AMI by Rb1, which was mainly associated with mitophagy. In vivo and in vitro experiments, Rb1 was found to improve mitochondrial morphology, mitochondrial function and promote mitophagy. Interestingly, the mitophagy inhibitor partly attenuated the cardioprotective effect of Rb1. Additionally, Rb1 markedly facilitated the phosphorylation of AMP-activated protein kinase a (AMPKa), and AMPK inhibition partially weakened the role of Rb1 in promoting mitophagy. Conclusions: Ginsenoside Rb1 protects acute myocardial ischemia injury through promoting mitophagy via AMPKa phosphorylation, which might lay the foundation for the further application of Rb1 in cardiovascular diseases.

Imaging the Enzymatic Reaction of Urease Using Liquid Crystal-Based pH Sensor

장창현,Qiong-Zheng Hu 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.12

In this study, real-time and label-free methods for monitoring the enzymatic reaction of urease, which releases ammonia through the hydrolysis of urea in an aqueous solution, were developed using a liquid crystal (LC)-based pH sensor. Nematic liquid crystal 4-cyano-4'-pentylbiphenyl (5CB), doped with 4'-pentyl-biphenyl-4-carboxylic acid (PBA), exhibited a shift in optical appearance from bright to dark when it was in contact with ammonia generated from the enzymatic reaction between urease and urea. This optical change was attributed to the anchoring transitions of LCs caused by hydrophobic interactions between the tails of deprotonted PBA (PBA^−) molecules and the LCs at the aqueous/LC interface. This novel technique holds great promise for the sensitive detection of urease along with its substrates and inhibitors.

On unicity of meromorphic solutions of differential-difference equations

Pei-Chu Hu,Qiong-Yan Wang 대한수학회 2018 대한수학회지 Vol.55 No.4

In this paper, we give a uniqueness theorem on meromorphic solutions $f$ of finite order of a class of differential-difference equations such that solutions $f$ are uniquely determined by their poles and two distinct values.

Encoding of XML Elements for Mining Association Rules

Gong Zhu Hu,Yan Liu,Qiong Huang 한국정보시스템학회 2005 情報시스템硏究 Vol.14 No.3

Structural behaviors of sustainable hybrid columns under compression and flexure

Wu Xiang-Guo,Hu Qiong,Zou Ruofei,Zhao Xinyu,Yu Qun 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.5

Structural behaviors of a sustainable hybrid column with the ultra high performance cementitious composites (UHPCC) permanent form under compression and flexure were studied. Critical state and failure stage characters are analyzed for large and small eccentricity cases. A simplified theoretical model is proposed for engineering designs and unified formulas for loading capacity of the hybrid column under compression and flexure loads are derived, including axial force and moment. Non-linear numerical analysis is carried out to verify the theoretical predictions. The theoretical predictions agree well with the numerical results which are verified by the short hybrid column tests recursively. Compared with the traditional reinforced concrete (RC) column, the loading capacity of the sustainable hybrid column is improved significantly due to UHPCC confinements.

Synthesis, characterization, and antioxidant activity in vitro of selenium‑Euryale ferox Salisb. polysaccharide

Dong Fang,Zheng Hu-Zhe,Jeong Woo-Sik,Chung Shin-Kyo,Qu Zhong-Yuan,Zou Xiang,Liu Chen,Xiang Qiong,Feng Feng 한국응용생명화학회 2021 Applied Biological Chemistry (Appl Biol Chem) Vol.64 No.S

In order to obtain and explore selenide composed of selenium and polysaccharide, three parameters were selected to optimize the synthesis process of selenium-Euryale ferox Salisb. polysaccharide (Se-ESPS) by Box-Behnken design. Furthermore, ESPS-B1 separated from ESPS was selenitized to Se-ESPS-B1 by the optimal synthesis process, then the characterization, and antioxidant activity in vitro of Se-ESPS-B1 were explored. The result manifested that the Se content of Se-ESPS was (2.915 ± 0.03) mg/g according to the optimal synthesis process of Se-ESPS (reaction time at 5 h, reaction temperature at 81 ℃, weight ratio of Na2SeO3 to ESPS at 0.9 g/g). A series of detection results indicated that the characterizations of Se-ESPS-B1 were apparently distinguished from that of ESPS-B1. Moreover, the antioxidant experiments in vitro demonstrated that Se-ESPS-B1 could exert antioxidant activity by scavenging DPPH, ABTS,·OH, and increasing reduction ability. In conclusion, the synthesis process is an effective approach to harvest seleniumpolysaccharide, and Se-ESPS-B1 may be utilized as a potential antioxidant or selenium nutritional supplement.

Phosphorylation of DYNLT1 at Serine 82 Regulates Microtubule Stability and Mitochondrial Permeabilization in Hypoxia

Xue Xu,Yue-sheng Huang,Qiong Zhang,Jiong-yu Hu,Dong-xia Zhang2,Xu-pin Jiang,jie-zhi Jia,Jing-ci Zhu 한국분자세포생물학회 2013 Molecules and cells Vol.36 No.4

Hypoxia-induced microtubule disruption and mitochondrial permeability transition (mPT) are crucial events leading to fatal cell damage and recent studies showed that microtubules (MTs) are involved in the modulation of mitochondrial function. Dynein light chain Tctex-type 1 (DYNLT1) is thought to be associated with MTs and mitochondria. Previously we demonstrated that DYNLT1 knockdown aggravates hypoxia-induced mitochondrial permeabilization, which indicates a role of DYNLT1 in hypoxic cytoprotection. But the underlying regulatory mechanism of DYNLT1 remains illusive. Here we aimed to investigate the phosphorylation alteration of DYNLT1 at serine 82 (S82) in hypoxia (1% O2). We therefore constructed recombinant adenoviruses to generate S82E and S82A mutants, used to transfect H9c2 and HeLa cell lines. Development of hypoxia-induced mPT (MMP examining, Cyt c release and mPT pore opening assay), hypoxic energy metabolism (cellular viability and ATP quantification), and stability of MTs were examined. Our results showed that phosph-S82 (S82-P) expression was increased in early hypoxia; S82E mutation (phosphomimic) aggravated mitochondrial damage, ele-vated the free tubulin in cytoplasm and decreased the cellular viability; S82A mutation (dephosphomimic) seemed to diminish the hypoxia-induced injury. These data suggest that DYNLT1 phosphorylation at S82 is involved in MTs and mitochondria regulation, and their interaction and cooperation contribute to the cellular hypoxic tolerance. Thus, we provide new insights into a DYNLT1 mechanism in stabilizing MTs and mitochondria, and propose a potential therapeutic target for hypoxia cytoprotective studies.