COMMON STATIONARY POINTS OF MULTI-VALUED F-CONTRACTIONS WITH δ-DISTANCE

Liu1 Zeqing,Liu Ying,Kang Shin Min 경남대학교 기초과학연구소 2019 Nonlinear Functional Analysis and Applications Vol.24 No.1

Three common stationary point theorems for some multi-valued F-contractions with δ-distance in bounded complete metric spaces are proved. The results obtained in this paper are extended or are different from several results in the literature. Three nontrivial examples are given.

Bioconversion of ginsenoside Rc into Rd by a novel α-L-arabinofuranosidase, Abf22-3 from Leuconostoc sp. 22-3: cloning, expression, and enzyme characterization.

Liu, Qing-Mei,Jung, Hae-Min,Cui, Chang-Hao,Sung, Bong-Hyun,Kim, Jin-Kwang,Kim, Song-Gun,Lee, Sung-Taik,Kim, Sun-Chang,Im, Wan-Taek N.V. Swets en Zeitlinger 2013 Antonie van Leeuwenhoek Vol.103 No.4

<P>A novel α-L-arabinofuranosidase (Abf22-3) that could biotransform ginsenoside Rc into Rd was obtained from the ginsenoside converting Leuconostoc sp. strain 22-3, isolated from the Korean fermented food kimchi. The gene, termed abf22-3, consisting of 1,527 bp and encoding a protein with a predicted molecular mass of 58,486 Da was cloned into the pMAL-c2x (TEV) vector. A BLAST search using the Abf22-3's amino acid sequence revealed significant homology to that of family 51 glycoside hydrolases. The over-expressed recombinant Abf22-3 in Escherichia coli BL21 (DE3) catalyzed the hydrolysis of the arabinofuranoside moiety attached to the C-20 position of ginsenoside Rc under optimal conditions of pH 6.0 and 30 C. This result indicated that Abf22-3 selectively converts ginsenoside Rc into Rd, but did not catalyze the hydrolysis of glucopyranosyl groups from Rc or other ginsenosides such as Rb1 and Rb2. Over-expressed recombinant enzymes were purified by two steps with amylose-affinity and DEAE-cellulose chromatography and then characterized. The kinetic parameters for α-L-arabinofuranosidase showed apparent Km and Vmax values of 0.95 0.02 μM and 1.2 0.1 μmol min(-1) mg of protein(-1) against p-nitrophenyl-α-L-arabinofuranoside, respectively. Using a purified MBP-Abf22-3 (10 μg/ml), 0.1 % of ginsenoside Rc was completely converted to ginsenoside Rd within 20 min.</P>

FSCB phosphorylation in mouse spermatozoa capacitation

( Shun Li Liu ),( Bing Ni ),( Xiang Wei Wang ),( Wen Qian Huo ),( Jun Zhang ),( Zhi Qiang Tian ),( Ze Min Huang ),( Yi Tian ),( Jun Tang ),( Yan Hua Zheng ),( Feng Shuo Jin ),( Yan Feng Li ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.8

It is generally accepted that spermatozoa capacitation is associated with protein kinase A-mediated tyrosine phosphorylation. In our previous study, we identified the fibrous sheath CABYR binding protein (FSCB), which was phosphorylated by PKA. However, the phosphorylation status of FSCB protein during spermatozoa capacitation should be further investigated. To this aim, in this study, we found that phosphorylation of this 270-kDa protein occurred as early as 1 min after mouse spermatozoa capacitation, which increased over time and remained stable after 60 min. Immunoprecipitation assays demonstrated that the tyrosine and Ser/Thr phosphorylation of FSCB occurred during spermatozoa capacitation. The extent of phosphorylation and was closely associated with the PKA activity and spermatozoa motility characteristics. FSCB phosphorylation could be induced by PKA agonist DB-cAMP, but was blocked by PKA antagonist H-89.Therefore, FSCB contributes to spermatozoa capacitation in a tyrosine-phosphorylated format, which may help in further elucidating the molecular mechanism of spermatozoa capacitation. [BMB reports 2011; 44(8): 541-546]

Soybean hull functionalized by phosphoric acid for sorption of copper from aqueous solution

Renmin Gong,Lingling Liu,Min Feng,Jiajing Zhao,Xingyan Liu,Shoujun Ni 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.2

One kind of potentially biodegradable cationic sorbent, which bears hydroxyl groups of phosphoric acid as its functional groups, with high sorption capacity of copper was prepared by thermochemically esterifying phosphoric acid (PA) onto soybean hull. Sorption of Cu(Ⅱ) from aqueous solution onto modified soybean hull (MSH) was investigated in a batch system. The sorption experiments were performed under various conditions such as different initial pH, copper concentration, MSH dosage, and contact time. The maximum copper sorption was obtained when initial solution pH≥3.5. The isothermal data of copper sorption fitted the Langmuir model and the sorption process could be described by the pseudo-first-order kinetic model. The maximum sorption capacity (Qm) of MSH for Cu(Ⅱ) was 31.55 mg/g. For 100 mg/l of Cu(Ⅱ) solution, a sorption ratio above 91% could be achieved by 5.0 g/l of MSH. The equilibrium of Cu(Ⅱ) sorption was reached within 50 min. The foreign cation and chelator in Cu(Ⅱ) solution caused decline of Cu(Ⅱ) sorption.

Chlorpropamide 2-hydroxylation is catalysed by CYP2C9 and CYP2C19 <i>in vitro</i>: chlorpropamide disposition is influenced by CYP2C9, but not by CYP2C19 genetic polymorphism

Shon, Ji-Hong,Yoon, Young-Ran,Kim, Min-Jung,Kim, Kyoung-Ah,Lim, Young-Chae,Liu, Kwang-Hyeon,Shin, Dong-Hoon,Lee, Chung Han,Cha, In-June,Shin, Jae-Gook Blackwell Science Ltd 2005 British journal of clinical pharmacology Vol.59 No.5

<P>Aims</P><P>We evaluated the involvement of cytochrome P450 (CYP) isoforms 2C9 and 2C19 in chlorpropamide 2-hydroxylation <I>in vitro</I> and in chlorpropamide disposition <I>in vivo</I>.</P><P>Methods</P><P>To identify CYP isoforms(s) that catalyse 2-hydroxylation of chlorpropamide, the incubation studies were conducted using human liver microsomes and recombinant CYP isoforms. To evaluate whether genetic polymorphisms of CYP2C9 and/or CYP2C19 influence the disposition of chlorpropamide, a single oral dose of 250 mg chlorpropamide was administered to 21 healthy subjects pregenotyped for CYP2C9 and CYP2C19.</P><P>Results</P><P>In human liver microsomal incubation studies, the formation of 2-hydroxychlorpropamide (2-OH-chlorpropamide), a major chlorpropamide metabolite in human, has been best described by a one-enzyme model with estimated <I>K</I><SUB><I>m</I></SUB> and <I>V</I><SUB>max</SUB> of 121.7 ± 19.9 µ<SMALL>M</SMALL> and 16.1 ± 5.0 pmol min<SUP>−1</SUP> mg<SUP>−1</SUP> protein, respectively. In incubation studies using human recombinant CYP isoforms, however, 2-OH-chlorpropamide was formed by both CYP2C9 and CYP2C19 with similar intrinsic clearances (CYP2C9 <I>vs.</I> CYP2C19: 0.26 <I>vs.</I> 0.22 µl min<SUP>−1</SUP> nmol<SUP>−1</SUP> protein). Formation of 2-OH-chlorpropamide in human liver microsomes was significantly inhibited by sulfaphenazole, but not by <I>S</I>-mephenytoin, ketoconazole, quinidine, or furafylline. In <I>in vivo</I> clinical trials, eight subjects with the <I>CYP2C9</I>*<I>1/</I>*<I>3</I> genotype exhibited significantly lower nonrenal clearance [*<I>1/</I>*<I>3 vs.</I>*<I>1/</I>*<I>1</I>: 1.8 ± 0.2 <I>vs.</I> 2.4 ± 0.1 ml h<SUP>−1</SUP> kg<SUP>−1</SUP>, <I>P</I> < 0.05; 95% confidence interval (CI) on the difference 0.2, 1.0] and higher metabolic ratios (of chlorpropamide/2-OH-chlorpropamide in urine: *<I>1/</I>*<I>3 vs.</I>*<I>1/</I>*<I>1</I>: 1.01 ± 0.19 <I>vs.</I> 0.56 ± 0.08, <I>P</I> < 0.05; 95% CI on the difference − 0.9, − 0.1) than did 13 subjects with <I>CYP2C9</I>*<I>1/</I>*<I>1</I> genotype. In contrast, no differences in chlorpropamide pharmacokinetics were observed for subjects with the <I>CYP2C19</I> extensive metabolizer <I>vs.</I> poor metabolizer genotypes.</P><P>Conclusions</P><P>These results suggest that chlorpropamide disposition is principally determined by CYP2C9 activity <I>in vivo</I>, although both CYP2C9 and CYP2C19 have a catalysing activity of chlorpropamide 2-hydroxylation pathway.</P>

Perturbed three-step iterative processes witherrors for general strongly nonlinear quasivariationalinequalities

Yali Zhao,Zeqing Liu,Shin Min Kang,Zunquan Xia 한국전산응용수학회 2005 Journal of applied mathematics & informatics Vol.17 No.1-2

In this paper, we introduce and study a class of general strongly nonlinear quasivariational inequalities in Hilbert spaces. We prove the existence and uniqueness of solution and convergence of the perturbed the three-step iterative sequences with errors for this kind of general strongly nonlinear quasivariational inquality problems involving relaxed Lipschitz, relaxed monotone, and strongly monotone mappings. Our results extend, improve, and unify many known results due to Liu-Ume-Kang, Kim-Kyung, Zeng and others

PERTURBED THREE-STEP ITERATIVE PROCESSES WITH ERRORS FOR GENERAL STRONGLY NONLINEAR QUASIVARIATIONAL INEQUALITIES

ZHAO, YALI,XIA, ZUNQUAN,LIU, ZEQING,KANG, SHIN MIN 한국전산응용수학회 2005 Journal of applied mathematics & informatics Vol.17 No.1

In this paper, we introduce and study a class of general strongly nonlinear quasivariational inequalities in Hilbert spaces. We prove the existence and uniqueness of solution and convergence of the perturbed the three-step iterative sequences with errors for this kind of general strongly nonlinear quasivariational inquality problems involving relaxed Lipschitz, relaxed monotone, and strongly monotone mappings. Our results extend, improve, and unify many known results due to Liu-Ume-Kang, Kim-Kyung, Zeng and others.

Distinctive Roles of Wnt Signaling in Chondrogenic Differentiation of BMSCs under Coupling of Pressure and Platelet-Rich Fibrin

Cheng Baixiang,Feng Fan,Shi Fan,Huang Jinmei,Zhang Songbai,Quan Yue,Tu Teng,Liu Yanli,Wang Junjun,Zhao Ying,Zhang Min 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.4

BACKGROUND: Although newly formed constructs of feasible pressure-preadjusted bone marrow mesenchymal stem cells (BMSCs) and platelet-rich fibrin (PRF) showed biomechanical flexibility and superior capacity for cartilage regeneration, it is still not very clear how BMSCs and seed cells feel mechanical stimuli and convert them into biological signals, and the difference in signal transduction underlying mechanical and chemical cues is also unclear. METHODS: To determine whether mechanical stimulation (hydrostatic pressure) and chemical cues (platelet-rich fibrin, PRF) activate canonical or noncanonical Wnt signaling in BMSCs, BMSCs cocultured with PRF were subjected to hydrostatic pressure loading, and the activation of the Wnt signaling molecules and expression of cartilage-associated proteins and genes were determined by western blotting and polymerase chain reaction (PCR). Inhibitors of canonical or noncanonical Wnt signaling, XVX-939 or L690,330, were adopted to investigate the role of Wnt signaling molecules in mechanically promoted chondrogenic differentiation of BMSCs. RESULTS: Hydrostatic pressure of 120 kPa activated both Wnt/b-catenin signaling and Wnt/Ca2? signaling, with the the maximum promotion effect at 60 min. PRF exerted no synergistic effect on Wnt/b-catenin signaling activation. However, the growth factors released by PRF might reverse the promotion effects of pressure on Wnt/Ca2? signaling. Real-time PCR and Western blotting results showed that pressure could activate the expression of Col-II, Sox9, and aggrecan in BMSCs cocultured with PRF. Blocking experiment found a positive role of Wnt/b-catenin signaling, and a negative role of Wnt/ Ca2? signaling in chondrogenic differentiation of the BMSCs. Mutual inhibition exists between canonical and noncanonical Wnt signaling in BMSCs under pressure. CONCLUSION: Wnt signaling participates in the pressure-promoted chondrogenesis of the BMSCs co-cultured with PRF, with canonical and noncanonical pathways playing distinct roles during the process.

Rapid HPLC determination of gastrodin in Gastrodiae Rhizoma

Lee, Ju-Gyeong,Moon, Sung-Ok,Kim, Se-Yong,Yang, Eun-Ju,Min, Ju-Sik,An, Ju-Hee,Choi, Eun-A,Liu, Kwang-Hyeon,Park, Eun Ji,Lee, Hwa-Dong,Song, Kyung-Sik 한국응용생명화학회 2015 Applied Biological Chemistry (Appl Biol Chem) Vol.58 No.3

Gastrodin is a major biologically active ingredient in members of the genus Gastrodia. For this reason, there are many reports on the quantification of gastrodin in Gastrodiae Rhizoma (GR) and in GR-containing herbal preparations. HPLC, HPLC-MS, and TLC are the major approaches for gastrodin quantification; however, they usually require complicated pre-treatment, lengthy analysis, and expensive instruments. Therefore, a rapid and reliable method for determining gastrodin in GR is necessary. Optimal HPLC separation was achieved using a Chromolith Performance RP-18e ($4.8{\times}100mm$, $5{\mu}m$) stationary phase. The optimal mobile phase was a mixture of water (A) and acetonitrile (B) with a gradient of 1 % B at 0-8 min, 20 % B at 8-10 min, 80-100 % B at 10-12 min, and 100 % B at 12-13 min, followed by equilibration with 1 % B for 2 min at a flow rate of 1.5 mL/min. The detection wavelength was UV220 nm. Gastrodin appeared within 4 min under the above conditions. The calibration curve of gastrodin showed good linearity in the 0.25-10.0 range ($r^2=0.9998$). The limit of detection ($0.13{\mu}g$), limit of quantification ($0.25{\mu}g$), and reproducibilities of area and retention time (0.04 and 3.24 %, respectively) were within acceptable ranges. In addition, the intra-day precision and accuracy of gastrodin were 0.74 and $100.63{\pm}0.04%$, respectively, while the inter-day precision and accuracy were 0.06 and $99.25{\pm}0.05%$, respectively. The range of mean gastrodin content in six GR samples, which were cultivated at different sites, was 0.37-0.79 %. This result may be a guideline for the quality control of GR and GR-containing medicinal preparations.

Defects evolution and element segregation of Ni-Mo-Cr alloy irradiated by 30 keV Ar ions

Liu Min,Liu Wenguan,He Xiujie,Gao Yantao,Liu Renduo,Zhou Xingtai 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.8

In present study, TEM foils of Ni-Mo-Cr alloy were directly irradiated with 30 keV Ar ions to allow direct characterization. The defects evolution and element segregation after irradiation were investigated by TEM and HAADF-EDS linear scanning. At low irradiation doses (1.38 and 2.76 dpa), black dots were formed and grew with increasing dose. Complicated defects including peas-shaped dislocation loops, polygon dislocation networks and large loops were visible in samples irradiated to high doses (13.8 and 27.6 dpa). Meanwhile, dislocation channels appeared, in which defects were swept out. Significant Mo depletions at dislocation lines and grain boundaries were induced by irradiation due to large misfits between Mo-Ni atoms and high content of Mo.