Test Study on the Air Permeability of Remolded Q3 Malan Loess

Jia Liu,Xi’an Li,Zeze Guo,Quan Xue,Li Wang,Jinyang Liu 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.8

Gas permeability is an important parameter in the determination of the pore structure characteristics of loess, especially in engineering fields such as earthwork and landfill cover treatment. With an improved ZC-2015 air permeameter, the air permeability (ka) testing under different water contents (w), dry densities (ρd) and wetting paths was conducted on remolded Q3 Malan loess from the Chanhe River area in Xi’an, Shaanxi, China. The results indicate that the ka of the remolded loess decreased rapidly as ρd increased and exhibited a relatively complex pattern as w increased. When w was less than the plastic limit (wp) and ρdwas relatively low (1.35 g·cm−3, 1.45 g·cm−3), ka decreased as we increased. When ρd reached a certain value (1.50 g·cm−3, 1.65 g·cm−3), the ka–we curve exhibited a notable turning point. When ρd continued to increase 1.70 g·cm−3, ka decreased as we increased. The results of microscopic analysis, suggested that under the action of different water content and compaction, levels of aggregates and pore structures were formed. A Poulsen model was used to predict the ka and the test results were in relatively coincident with the calculation results, demonstrating that the Poulsen model is applicable.

소 뇌 조직으로부터 5'-Nucleotidase의 정제 및 특성규명

류희문,석대은 충남대학교 약학대학 의약품개발연구소 2002 藥學論文集 Vol.17 No.-

5'-Nucleotidase, bound to brain membranes as a glycosylphosphatidyl-inositol (GPI)-anchored protein, is responsible for the conversion of adenosine-5'-monophosphate into adenosine, which is an agonist in adenosine receptor signalling. Here, 5'-nucleotidase was isolated from bovine brain using PI-PLC treatment, and purified by concanavalin A sepharose chromatography, DEAE-sephacel chromatography, and finally AMP affinity chromatography. For higher yield of enzyme purification, Zn^2+ was Included in the elution buffer in DEAE-sephacel chromatography. Especially, NaCl was more favorable than MgCl_2 for the elution of 5'-nucleotidase, proper for inactivation study, from AMP affinity column. The purified 5'-nucleotidase was relatively pure on SDS-PAGE analysis, showing a specific activity of 30.27 μmole/min/㎎ (purification fold 19,000 fold). The purified enzyme, possessing a K_m value of 44μM and an optimum pH of 7.5, was inhibited competitively by ATP (K_i, 12 μM), and uncompetitively by cysteine (K_i, 0.32 mM). In addition, the enzyme was activated slighty (1.5-folds) by Mg^2+.

효소 Lipoxygenase의 신규기질 : Acylglycerol, acylethanolamide, lysophospholipids 및 phospholipids

황룡쌍,류희문,박천호,석대은 충남대학교 약학대학 의약품개발연구소 2007 藥學論文集 Vol.22 No.-

Lipoxygenase belongs to a diverse family of nonheme ferroproteins that oxygenate polyenoic fatty acids containing 1,4-pentadiene structure to form their corresponding hydroperoxy derivatives. Lipoxygenases (LOXs), widely distributed in animals and plants, have a key function in the formation of biologically active substances from pulyunsaturated fatty acids. Generally, free polyunsaturated fatty acids, liberated from membrane phospholipids via phospholipase-catalyzed hydrolysis, are used as substrates for LOXs. Although it is acknowledged that free polyunsaturated fatty acids are preferred to phospholipids or triglycerides as substrates, there have been recent reports that mammalian enzymes can oxidize certain phospholipids. Especially, reticulocyte LOX (15-LOX) leukocyte 15-LOX, leukocyte LOX (12-LOX) can oxygenate complex substrates such as phospholipids and biomembranes. In addition, acylglycerol and acylethanolamide are utilized by lipoxygeanse as well as cycoloxygenase; the latter enzyme contributes to generation of bioactive prostanoids derivative. Furthermore, lysophosphatidylcholine or lysophosphatidic acid containing linoleoyl or arachidonoyl moieties are known to be oxygenated by reticulocyte LOX, leukocyte 15-LOX or leukocyte-type 12-LOX; oxygenated lysophospholipids can play a carrier role in transporting oxygenated derivatives. Thus, the use of various lipid substrates as new substrates for lipoxygenase may extend the physiological roles of those lipids containing unsaturated fatty acyl chains.

Cumene hydroperoxide에 의한 paraoxonase 1의 산화적 불활성화에 대한 보호 방안

스, 위엥쥐,류희문,김주령,석대은 충남대학교 약학대학 의약품개발연구소 2003 藥學論文集 Vol.18 No.-

Paraoxonase 1 (PON1), an enzyme associated with high density lipoprotein (HDL), is known to protect low density lipoprotein (LDL) from lipid peroxidation involving copper ion. However, Paraoxonase 1 activity was observed to decrease during LDL oxidation. Here, the inactivation of PON1 by various peroxides was examined. Paraoxonase 1, purified from human plasma, was subjected to cumene hydroperoxide, hydrogen peroxide or tert-butyl hydroperoxide. PON activity, based on the hydrolysis of phenyl acetate, decreased by approximately 40 and 38 %, respectively, after the exposure to 2mM cumene hydroperoxide and hydrogen peroxide, while tert-butyl hydroperoxide had no remarkable inhibitory effect. Next, the compounds capable of preventing against cumene hydroperoxide-induced inactivation of PONl were screened. While quercetin or phenyl acetate failed to protect PON1, lauric acid or calcium chloride was found to protect PONl from cumene hydroperoxide-induced inactivation. Especially, lauric acid appeared to show the greater protection than the other fatty acids tested. In further study, lauric acid showed a dose-dependent protection with an E& value of around 35 μM. Based on these results, It is proposed that the alky hydroperoxide-induced inactivation of Paraoxonase 1 can be prevented by a proper fatty acid recipe.

인체 혈장 Paraoxonase의 산화적 불활성화

위엥쥐스,김주령,정태숙,류희문,석대은 충남대학교 약학대학 의약품개발연구소 2002 藥學論文集 Vol.17 No.-

Paraoxonase (PON), an enzyme associated with high density lipoprotein (HDL), is known to protect low density lipoprotein (LDL) from lipid peroxidation involving copper ion. However, PON activity was observed to decrease during LDL oxidation. Here, we attempted to elucidate the possible mechanism for the inactivation of PON. PON was partially purified from human plasma, and subjected to various oxidant systems. PON activity, based on the hydrolysis of phenyl acetate, decreased slightly after the exposure to H_2O_2 or ascorbate, while oxidants such as peroxynitrite or HOCl had no remarkable effect. Inclusion of Cu^2+ in the incubation with ascorbate (0.3∼1 mM) led to a rapid decrease of activity in a time-and concentration-dependent manner. In comparison, ascorbate/Cu^2+ system was much more effective than ascorbate/Fe^2+ system in inactivating PON. A further study indicates that general hydroxyl radical scavengers such as mannitol, ethanol or benzoate failed to prevent the PON inactivation. Based on these results, it is proposed that the PON inactivation during LDL oxidation may be ascribed mainly to the Cu^2+-catalyzed oxidation.

Genetic dissection of leaf-related traits using 156 chromosomal segment substitution lines

Xi Liu,Linglong Liu,Yinhui Xiao,Shijia Liu,Yunlu Tian,Liangming Chen,Zhiquan Wang,Ling Jiang,Zhigang Zhao,Jianmin Wan 한국식물학회 2015 Journal of Plant Biology Vol.58 No.6

A two-line super-hybrid rice (Oryza sativa L.) variety [Liangyoupei9 (LYP9)] demonstrated superiority over its both parents, viz. elite inbred lines 93-11 and Pei-ai64S (PA64S), as well as other conventional hybrids, and had long been exploited in China. However, the genetic basis of its leaf-related traits, supposed to be an important component for yield potential, remains elusive. Here, initially a set of chromosome segment substitution lines (CSSLs) was constructed, in which the genome of Pei-ai64S has been introgressed into the background of 93-11. This set was developed by marker aided selection, based on 123 polymorphic SSR markers. The introgressed chromosomal segments presented in the 156 CSSLs covered 96.46% of Pei-ai64S genome. Afterwards, the CSSLs were deployed to assess the genetic basis of leaf size (length and width) and chlorophyll content of top three leaves across five different environments. The CSSLs showed transgressive segregation for all of the traits, and significant correlations were detected among most of the traits. A total of 27 quantitative trait loci (QTL) were identified on ten chromosomes, and three QTL cluster affecting related traits were found on chromosome 3, 6, and 8, respectively. Remarkably, two key QTLs, qALW3-1 and qALW3-2, both controlling the antepenultimate leaf width, were identified in all five environments, and their effect were further validated by CSSLs harboring the two QTL alleles. Our results indicate that developing CSSLs is a powerful tool for genetic dissection of quantitative traits. Meanwhile, the QTLs controlling leaf-related traits uncovered here provide useful information for marker-assisted selection in improving the performance of leaf morphology and photosynthetic ability.

Inhibition of lysophospholipase D activity by fish egg extracts

Liu, Xi-Wen,Shim, Hyun Jung,Son, Chan Wok,Kim, Mi Yeon,Kim, Min Hee,Cui, Hui Song,Park, Cheon Ho,Sok, Dai-Eun,Kim, Mee Ree Springer-Verlag 2009 European food research and technology Vol.228 No.3

Prognostic Impact of Cyclin D1, Cyclin E and P53 on Gastroenteropancreatic Neuroendocrine Tumours

Liu, Shu-Zheng,Zhang, Fang,Chang, Yu-Xi,Ma, Jie,Li, Xu,Li, Xiao-Hong,Fan, Jin-Hu,Duan, Guang-Cai,Sun, Xi-Bin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Conventional classifications of gastroenteropancreatic neuroendocrine tumours (GEP-NETs) are rather unsatisfactory because of the variation in survival within each subgroup. Molecular markers are being found able to predict patient outcome in more and more tumours. The aim of this study was to characterize the expression of the proteins cyclin D1, cyclin E and P53 in GEP-NETs and assess any prognostic impact. Tumor specimens from 68 patients with a complete follow-up were studied immunohistochemically for cyclin D1, cyclin E and P53 expression. High cyclin D1 and cyclin E immunostaining (${\geq}$ 5% positive nuclei) was found in 48 (71%) and 24 (35%) cases, and high P53 staining (${\geq}$ 10% positive nuclei) in 33 (49%). High expression of P53 was more common in gastric neuroendocrine tumors and related to malignant behavior, being associate with a worse prognosis on univariate analysis (RR=1.9, 95%CI=1.1-3.2). High expression of cyclin E was significantly associated with shorter survival in the univariate analysis (RR=2.0, 95%CI=1.2-3.6) and multivariate analysis (RR=2.1, 95%CI=1.1-4.0). We found no significant correlation between the expression of cyclin D1 and any clinicopathological variables. Our study indicated a prognostic relevance for cyclin E and P53 immunoreactivity. Cyclin E may be an independent prognostic factor from the 2010 WHO Classification which should be evaluated in further studies.

The Role of Perceived Brand Nature and Self-regulatory Focus on Chinese consumers’ Purchase Intentions

LIU XI(유시아),Bangwool Han(한방울) 한국산업경제학회 2022 한국산업경제학회 정기학술발표대회 논문집 Vol.2022 No.6

Universality of Finite-Size Corrections to Geometrical Entanglement in One-Dimensional Quantum Critical Systems

Xi-Jing Liu,Bing-Quan Hu,Sam Young Cho,Huan-Qiang Zhou,Qian-Qian Shi 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.7

Recently, the finite-size corrections to the geometrical entanglement per lattice site in the spin- 1/2 chain have been numerically shown to scale inversely with system size, and its prefactor b has been suggested to be possibly universal [Q-Q. Shi et al., New J. Phys. 12, 025008 (2010)]. As possible evidence of its universality, the numerical values of the prefactors have been confirmed analytically by using the Affleck-Ludwig boundary entropy with a Neumann boundary condition for a free compactified field [J-M. Stephan et al., Phys. Rev. B 82, 180406(R) (2010)]. However, the Affleck-Ludwig boundary entropy is not unique and does depend on conformally invariant boundary conditions. Here, we show that a unique Affleck-Ludwig boundary entropy corresponding to a finitesize correction to the geometrical entanglement per lattice site exists and show that the ratio of the prefactor b to the corresponding minimum groundstate degeneracy gmin for the Affleck- Ludwig boundary entropy is a constant for any critical region of the spin-1 XXZ system with the single-ion anisotropy, i.e., b/(2 log2 gmin) = −1. Previously studied spin-1/2 systems, including the quantum three-state Potts model, have verified the universal ratio. Hence, the inverse finite-size correction to the geometrical entanglement per lattice site and its prefactor b are universal for one-dimensional critical systems.