Determination of the Kinetic Properties of Platycodin D for the Inhibition of Pancreatic Lipase Using a 1,2-Diglyceride-Based Colorimetric Assay

Zhao, Hai Lin,Kim , Yeong-Shik The Pharmaceutical Society of Korea 2004 Archives of Pharmacal Research Vol.27 No.10

A 1, 2-diglyceride-based multi-step colorimetric assay to measure the pancreatic lipase activity was applied for the determination of the kinetic profiles of the lipase inhibition with a slight modification and the validity verification. With this assay method, our study revealed that platycodin D, one of major constituents of Platycodi Radix, inhibits the pancreatic lipase activity in a competitive type, with the value of $K_I$ being 0.18${\pm}$0.02 mM. In addition, PD has affected the values of $K_{m,app}\;and\;K_{cat}/K_m$ in a dose- dependent manner. The results shed a meaningful light on how PD mediates lipid metabolism in the intestinal tracts. On the other hand, since the revised assay is sensitive, rapid, and does not affect the accuracy to the kinetic properties, it is applicable not only to evaluation of the kinetic properties of the pancreatic lipase, but also to highthroughput screening of pancreatic lipase activity.

Determination of the Kinetic Properties of Platycodin D for the Inhibition of Pancreatic Lipase Using a 1,2-Diglyceride-Based Colorimetric Assay

Hai Lin Zhao,Yeong Shik Kim 대한약학회 2004 Archives of Pharmacal Research Vol.27 No.9

A 1, 2-diglyceride-based multi-step colorimetric assay to measure the pancreatic lipase activity was applied for the determination of the kinetic profiles of the lipase inhibition with a slight modification and the validity verification. With this assay method, our study revealed that platycodin D, one of major constituents of Platycodi Radix, inhibits the pancreatic lipase activity in a competitive type, with the value of KI being 0.18±0.02 mM. In addition, PD has affected the values of Km, app and Kcat/Km in a dose- dependent manner. The results shed a meaningful light on how PD mediates lipid metabolism in the intestinal tracts. On the other hand, since the revised assay is sensitive, rapid, and does not affect the accuracy to the kinetic properties, it is applicable not only to evaluation of the kinetic properties of the pancreatic lipase, but also to highthroughput screening of pancreatic lipase activity.

Cholesterol-lowering effect of platycodin D in hypercholesterolemic ICR mice

Zhao, Hai Lin,Cho, Kyung-Hyun,Ha, Young Wan,Jeong, Tae-Sook,Lee, Woo Song,Kim, Yeong Shik Elsevier 2006 european journal of pharmacology Vol.537 No.1

<P><B>Abstract</B></P><P>This study investigates the in vivo hypocholesterolemic action of platycodin D and its in vitro evidence for the cholesterol-lowering properties. In order to examine the effects of platycodin D on hypercholesterolemia in male ICR mice, platycodin D with doses of 15, 30 or 50?mg/kg was orally administered for 8 weeks. Changes in body weight and daily food intake were measured regularly during the experimental period. Final contents of triglyceride and different types of cholesterol in the serum, livers and feces were determined. The effects of platycodin D on cholesterol metabolism were further investigated with several in vitro assays, including antioxidant effect on low density lipoprotein oxidation, inhibition of human acyl-coenzyme A:cholesterol acyltransferase (hACAT) and serum lipoprotein associated-phospholipase A<SUB>2</SUB> (Lp-PLA<SUB>2</SUB>), as well as the regulation of farnesoid X receptor. The formation of insoluble complex between platycodin D and cholesterol was also investigated. Following an eight week experimental period, the body weights of platycodin D-fed mice were less than those of control mice on a high cholesterol diet by 11.2±5% (<I>P</I><0.01) with 15 mg/kg platycodin D, 11.7±5% (<I>P</I><0.01) with 30?mg/kg platycodin D, and 23.4±7.9% (<I>P</I><0.0001) with 50?mg/kg platycodin D, respectively. A decrease in daily food consumption was also noted in most of the treated animals. Triglyceride and cholesterol concentrations were decreased in serums and livers, but increased in feces. Some of the in vitro observations revealed that the hypocholesterolemic effect of platycodin D is partly associated with inhibition to hACAT activity and antagonism to the farnesoid X receptor as well as the formation of insoluble complex with between platycodin D and cholesterol. Both in vivo and in vitro results demonstrate a potential value of platycodin D as a novel cholesterol-lowering and anti-atherogenic candidate.</P>

Behavior and calculation on concrete-filled steel CHS (Circular Hollow Section) beam-columns

Lin-Hai Han,Guo-Huang Yao,Xiao-Ling Zhao 국제구조공학회 2004 Steel and Composite Structures, An International J Vol.4 No.3

A mechanics model is developed in this paper for concrete-filled steel CHS (circular hollow section) beam-columns. A unified theory is described where a confinement factor (ξ) is introduced to describe the composite action between the steel tube and the filled concrete. The predicted load versus deformation relationship is in good agreement with test results. The theoretical model was used to investigate the influence of important parameters that determine the ultimate strength of concrete-filled steel CHS beam-columns. The parametric and experimental studies provide information for the development of formulas for the calculation of the ultimate strength of the composite beam-columns. Comparisons are made with predicted beam-columns strengths using the existing codes, such as LRFD-AISC-1999, AIJ-1997, BS5400-1979 and EC4-1994.

Space-vector PWM Techniques for a Two-Phase Permanent Magnet Synchronous Motor Considering a Reduction in Switching Losses

Hai Lin,Fei Zhao,Byung-il Kwon 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Two PWM techniques using space vector pulse-width modulation (SVPWM) are proposed for a two-phase permanent magnet synchronous motor (PMSM) driven by a two-phase eightswitch inverter. A two-phase motor with two symmetric stator windings is usually driven by a twophase four-, six-, or eight-switch inverter. Compared with a four- and six-switch inverter, a two-phase eight-switch inverter can achieve larger power output. For two-phase motor drives, the SVPWM technique achieves more efficient DC bus voltage utilization and less harmonic distortion of the output voltage. For a two-phase PMSM fed by a two-phase eight-switch inverter under a normal SVPWM scheme, each of the eight PWM trigger signals for the inverter have to be changed twice in a cycle, causing a higher PWM frequency. Based on the normal SVPWM scheme, two effective SVPWM schemes are investigated in order to reduce the PWM frequency by rearranging four comparison values, while achieving the same function as the normal PWM scheme. A detailed explanation of the normal and two proposed SVPWM schemes is illustrated in the paper. The experimental results demonstrate that the proposed schemes achieve a better steady performance with lower switching losses compared with the normal scheme.

Tests and mechanics model for concrete-filled SHS stub columns, columns and beam-columns

Lin-Hai Han,Xiao-Ling Zhao,Zhong Tao 국제구조공학회 2001 Steel and Composite Structures, An International J Vol.1 No.1

A series of tests on concrete-filled SHS (Square Hollow Section) stub columns (twenty), columns (eight) and beam-columns (twenty one) were carried out. The main parameters varied in the tests are (1) Confinement factor (x ) from 1.08 to 5.64, (2) concrete compression strength from 10.7MPa to 36.6MPa, (3) tube width to thickness ratio from 20.5 to 36.5. (4) load eccentricity (e) from 15 mm to 80 mm and (5) column slenderness (l) from 45 to 75. A mechanics model is developed in this paper for concrete-filled SHS stub columns, columns and beam-columns. A unified theory is described where a confinement factor (x ) is introduced to describe the composite action between the steel tube and filled concrete. The predicted load versus axial strain relationship is in good agreement with stub column test results. Simplified models are derived for section capacities and modulus in different stages of the composite sections. The predicted beam-column strength is compared with that of 331 beam-column tests with a wide range of parameters. A good agreement is obtained. The predicted load versus midspan deflection relationship for beam-columns is in good agreement with test results. A simplified model is developed for calculating the member capacity of concrete-filled SHS columns. Comparisons are made with predicted columns strengths using the existing codes such as LRFD (AISC 1994), AIJ (1997), and EC4 (1996). Simplified interaction curves are derived for concrete-filled beam-columns.

Development of Integrated Multi-Station System to Precisely Detect and Mitigate Surface Damage on Fused Silica Optics

Lin-Jie Zhao,Jian Cheng,Ming-Jun Chen,Xiao-Dong Yuan,Wei Liao,Hao Yang,Qi Liu,Hai-Jun Wang 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.1

In high power laser facility, irreversible damage on fused silica optics, induced by laser irradiation or processing, seriously affects the service life of optics. Therefore, the work of inhibiting damage growth has been carried out in various countries. In our work, an integrated multi-station system is designed to detect and mitigate surface damage on fused silica. The process of processing fused silica optics include UV laser conditioning, surface damage detection and surface damage mitigation with CO2 laser. UV laser conditioning pre-initiates surface damage on fused silica optics with the laser flux less than Laser-Induced Damage Threshold (LIDT). Images of surface damage acquired from camera are processed by improved global threshold segmentation algorithm to extract damage information. Finally, CO2 laser is applied to process the damage with specific morphology to enhance the laser damage resistance. This integrated multi-station system saves the repeated optics installation time between the workstations with the positioning accuracy of 20 μm. Furthermore, the damage with diameter of 10 μm is mitigated to prolong service life of processed fused silica optics. The efficient and accurate integrated multi-station system is of great significance for off -line detecting and mitigating surface damage of fused silica optics in high power laser facility.

Space-vector PWM Techniques for a Two-Phase Permanent Magnet Synchronous Motor Considering a Reduction in Switching Losses

Lin, Hai,Zhao, Fei,Kwon, Byung-il The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Two PWM techniques using space vector pulse-width modulation (SVPWM) are proposed for a two-phase permanent magnet synchronous motor (PMSM) driven by a two-phase eight-switch inverter. A two-phase motor with two symmetric stator windings is usually driven by a two-phase four-, six-, or eight-switch inverter. Compared with a four- and six-switch inverter, a two-phase eight-switch inverter can achieve larger power output. For two-phase motor drives, the SVPWM technique achieves more efficient DC bus voltage utilization and less harmonic distortion of the output voltage. For a two-phase PMSM fed by a two-phase eight-switch inverter under a normal SVPWM scheme, each of the eight PWM trigger signals for the inverter have to be changed twice in a cycle, causing a higher PWM frequency. Based on the normal SVPWM scheme, two effective SVPWM schemes are investigated in order to reduce the PWM frequency by rearranging four comparison values, while achieving the same function as the normal PWM scheme. A detailed explanation of the normal and two proposed SVPWM schemes is illustrated in the paper. The experimental results demonstrate that the proposed schemes achieve a better steady performance with lower switching losses compared with the normal scheme.

Clinical Microbiology and Biomedical Sciences : Construction and Characterization of an Enhanced GFP-Tagged TIM-1 Fusion Protein

( Ji Lin Qing ),( Hai Bing Xiao ),( Lin Zhao ),( Gui Fang Qin ),( Li Hua Hu ),( Zhi Zhong Chen ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.4

TIM-1 (also known as KIM-1 and HAVcr-1) is a type I transmembrane glycoprotein member of the TIM family that may play important roles in innate and adaptive immune responses. The overexpression of proteins associated with membrane proteins is a major obstacle to overcome in studies of membrane protein structures and functions. In this study, we successfully coupled the overexpression of the TIM-1 protein with a C-terminal enhanced green fluorescent protein (GFP) tag in Escherichia coli. To the best of our knowledge, this report is the first to describe the overexpression of human TIM-1 in E. coli. The purified TIM-1-EGFP fusion protein recognized and bound directly to apoptotic cells and did not to bind to viable cells. Furthermore, we confirmed that the interactions of TIM-1-EGFP with apoptotic cells were blocked by TIM-1-Fc fusion proteins. This fusion protein represents a readily obtainable source of biologically active TIM-1 that may prove useful in future studies of human TIM-1.

Galectin-9 Acts as a Prognostic Factor with Antimetastatic Potential in Hepatocellular Carcinoma

Zhang, Zhao-Yang,Dong, Jia-Hong,Chen, Yong-Wei,Wang, Xian-Qiang,Li, Chong-Hui,Wang, Jian,Wang, Guo-Qiang,Li, Hai-Lin,Wang, Xue-Dong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Considerable research has been conducted concerning galectin-9 and carcinomas, but little information is available about any relation with the hepatocellular carcinoma. In this study, we employed a small interfering RNA (siRNA) targeting galectin-9 to down-regulate the expression in HepG2 cells. As a result, after galectin-9 expression was reduced, cell aggregation was suppressed, while other behaviour such as the proliferation, adhesion and invasion to ECM, cell-endothelial adhesion and transendothelial invasion of the cells were markedly enhanced. When tumors of 200 patients with hepatocellular carcinoma were tested for galectin-9 expression by immunohistochemistry, binding levels demonstrated intimate correlations with the histopathologic grade, lymph node metastasis, vascular invasion and intrahepatic metastasis (P<0.05). Moreover, survival analysis indicated that patients with galectin-9 expression had much longer survival time than those with negative lesions, and the Log-rank test indicated that this difference was statistical significant (P<0.0001). The Cox proportional hazards model suggested that negative galectin-9 expression in hepatocellular carcinoma represented a significant risk factor for patient survival. We propose that galectin-9 might be a new prognostic factor with antimetastatic potential in patients with hepatocellular carcinoma.