Acanthopanax senticosus Extract Prepared from Cultured Cells Improves Lipid Parameters in Rats Fed with a High Fat Diet

Youn-Soo Cha,Ju-Ryoun Soh,Jae-Whune Kim 한국식품영양과학회 2003 Preventive Nutrition and Food Science Vol.8 No.1

Acanthopanax senticosus was grown by a novel, proprietary method, of culturing isolated cells in a bioreactor. An extract from the cells was evaluated for its effect on lipid metabolism in rats fed a high fat diet. Male Sprague-Dawley rats (n=6) were fed either an AIN-76 diet (control, NDCon), control diet plus Acanthopanax senticosus extract (ND+Ex), a modified AIN-76 diet supplemented with 20% beef tallow (high fat, HFCon), or a high fat diet plus Acanthopanax senticosus extract (HF+Ex), for 5weeks. Body weight gain was significantly higher in the HFCon group than the NDCon group. Feed consumption was significantly lower, but energy intake higher, in the groups fed high fat diets compared with the groups fed control diets. Serum HDL-cholesterol concentrations were significantly increased but serum LDL-cholesterol concentrations were decreased in the groups fed the Acanthopanax senticosus extract. Abdominal fat accumulation, serum leptin levels were significantly higher in the HFCon group than the other groups. Carnitine palmitoyltransferase-I (CPT-I) mRNA levels were increased in the groups fed Acanthopanx senticosus extract. These results suggest that supplementation of cell cultured Acanthopanax senticosus extract regulates CPT-I mRNA levels in liver, has an effect on the normalization of lipids in rats fed a high fat diet.

Q 열에 의한 감염성 심내막염 2예

문수연,최영실,박미연,이정아,정미경,정혜숙,정두련,송재훈,백경란 대한감염학회 2009 감염과 화학요법 Vol.41 No.3

Q fever is a zoonosis caused by Coxiella burnetii, Presenting as acute and chronic illness and it has been reported worldwide. Acute Q fever is usually asymptomatic or mild and self-limiting, but infective endocarditis is one of the most serious complications of chronic Q fever and can be fatal. Known risk factors for Q fever endocarditis are valvular heart disease, immunocompromised hosts, and pregnancy. There have been some reports on Q fever in Korea but there exists no report on Q fever endocarditis. We have experienced 2 cases of Q fever with underlying valvular heart disease; both Patients came to the hospital for evaluation of prolonged fever. Although Q fever and Q fever endocarditis are rare in Korea, Q fever endocarditis should be considered in the differential diagnosis of patient with infective endocarditis when causative microorganism cannot be identified.

Acanthopanax senticosus Extract Prepared from Cultured Cells Improves Lipid Parameters in Rats Fed with a High Fat Diet

Cha, Youn-Soo,Soh, Ju-Ryoun,Kim, Jae-Whune The Korean Society of Food Science and Nutrition 2003 Preventive Nutrition and Food Science Vol.8 No.1

Acanthopanax senticosus was grown by a novel, proprietary method, of culturing isolated cells in a bioreactor. An extract from the cells was evaluated for its effect on lipid metabolism in rats fed a high fat diet. Male Sprague-Dawley rats (n=6) were fed either an AIN-76 diet (control, NDCon), control diet plus Acanthopanax senticosus extract (ND+Ex), a modified AIN-76 diet supplemented with 20% beef tallow (high fat, HFCon), or a high fat diet plus Acanthopanax senticosus extract (HF+Ex), for 5weeks. Body weight gain was significantly higher in the HFCon group than the NDCon group. Feed consumption was significantly lower, but energy intake higher, in the groups fed high fat diets compared with the groups fed control diets. Serum HDL-cholesterol concentrations were significantly increased but serum LDL-cholesterol concentrations were decreased in the groups fed the Acanthopanax senticosus extract. Abdominal fat accumulation and serum leptin levels were significantly higher in the HFCon group than the other groups. Carnitine palmitoyltransferase-I (CPT-I) mRNA levels were increased in the groups fed Acanthopanx senticosus extract. These results suggest that supplementation of cell cultured Acanthopanax senticosus extract regulates CPT-I mRNA levels in liver and has an effect on the normalization of lipids in rats fed a high fat diet.

Sustainable antireflection using recoverable nanopattern arrays

Park, Juhyuk,Youn, Jae Ryoun,Song, Young Seok The Royal Society of Chemistry 2017 Journal of Materials Chemistry C Vol.5 No.40

<▼1><P>This research proposes a unique antireflection (AR) strategy which is to infuse shape recovery ability into nanopattern arrays for obtaining high sustainability of the AR nanostructures.</P></▼1><▼2><P>Antireflection (AR) nanostructures mimicking a moth's eye have been developed for optical devices to achieve a high transmittance of light energy. However, mechanical vulnerability has always been pointed out as a drawback of these nanostructures. This research proposes a unique AR strategy which is to infuse shape recovery ability into nanopattern arrays for obtaining high sustainability of the AR nanostructures. A shape memory polymer (SMP) was prepared through tri-copolymerization, where the transition temperature was modulated close to body temperature for facile shape recovery. Nanoscale shape recoverability of the patterns was explored at body temperature. Light transmittance was analyzed experimentally according to the shape state of the AR nanopatterns, and the shape recovery function restored 50% of the damaged antireflection performance. The underlying mechanism of the sustainable AR based on nanopatterns was suggested by calculating theoretical transmittance. Omnidirectional antireflectivity by the nanopatterns was examined by measuring oblique incident transmittances with their sustainability. The nanomechanical properties and the sustainable self-cleaning effect induced by the smart nanostructures were also confirmed experimentally. We foresee that the approach suggested in this study can provide new insights into biomimetic optics.</P></▼2>

Encapsulated Phase Change Material Embedded by Graphene Powders for Smart and Flexible Thermal Response

Yu, Chengbin,Youn, Jae Ryoun,Song, Young Seok 한국섬유공학회 2019 Fibers and polymers Vol.20 No.3

Three dimensional flow analysis within a profile extrusion die by using control volume finite-element method

Kim, Jongman,Youn, Jae-Ryoun,Hyun, Jae-Chun The Korean Society of Rheology 2001 Korea-Australia rheology journal Vol.13 No.2

Three-dimensional flow analysis was performed by using the control volume finite-element method for design of a profile extrusion die. Because polymer melt behavior is complicated and cross-sectional shape of the profile extrusion die is changing continuously, the fluid flow within the die must be analyzed three-dimensionally. A commercially available polypropylene is used for theoretical and experimental investigations. Material properties are assumed to be constant except for the viscosity. The 5-constant modified Cross model is used for the numerical analysis. A test problem is examined in order to verify the accuracy of the numerical method. Simulations are performed for conditions of three different screw speeds and three different die temperatures. Predicted pressure distribution is compared with the experimental measurements and the results of the previous two-dimensional study. The computational results obtained by using three dimensional CVFEM agree with the experimental measurements and are more accurate than those obtained by using the two-dimensional cross-sectional method. The velocity profiles and the temperature distributions within several cross-sections of the die are given as contour plots.

Constitutive Equations for Dilute Bubble Suspensions and Rheological Behavior in Simple Shear and Uniaxial Elongational Flow Fields

Seo Dongjin,Youn Jae Ryoun The Korean Fiber Society 2005 Fibers and polymers Vol.6 No.2

A theoretical model is proposed in order to investigate rheological behavior of bubble suspension with large deformation. Theoretical constitutive equations for dilute bubble suspensions are derived by applying a deformation theory of ellipsoidal droplet [1] to a phenomenological suspension theory [2]. The rate of deformation tensor within the bubble and the time evolution of interface tensor are predicted by applying the proposed constitutive equations, which have two free fitting parameters. The transient and steady rheological properties of dilute bubble suspensions are studied for several capillary numbers (Ca) under simple shear flow and uniaxial elongational flow fields. The retraction force of the bubble caused by the interfacial tension increases as bubbles undergo deformation. The transient and steady relative viscosity decreases as Ca increases. The normal stress difference (NSD) under the simple shear has the largest value when Ca is around 1 and the ratio Of the first NSD to the second NSD has the value of 3/4 for large Ca but 2 for small Ca. In the uniaxial elongational flow, the elongational viscosity is three times as large as the shear viscosity like the Newtonian fluid.

Flow Analysis of Profile Extrusion by a Modified Cross-sectional Numerical Method

Seo, Dongjin,Youn, Jae-Ryoun The Korean Fiber Society 2000 Fibers and polymers Vol.1 No.2

Flow analysis of profile extrusion is essential for design and production of a profile extrusion die. Velocity, pressure, and temperature distribution in an extrusion die are predicted and compared with the experimental results. A two dimensional numerical method is proposed for three dimensional analysis of the flow field within the profile extrusion die by applying a modified cross-sectional numerical method. Since the cross-sectional shape of the die is varied gradually, it is assumed that the pressure is constant within a cross-sectional plane that is perpendicular to the flow direction. With this assumption, the velocity component in the cross-sectional direction is neglected. The exact cross-sectional shape at any position is calculated based on the geometry of standard cross-sections. The momentum and energy equations are solved with proper boundary conditions at a cross-section and then the same calculation is carried out for the next cross-section using the current calculated values. An L-shaped profile extrusion die is produced and employed for experimental investigation using a commercially available polypropylene. Numerical prediction for the varying cross-sectional shape provides better results than the previous studies and is in good agreement with the experimental results.

Carbon Nanotube Embedded Nanostructure for Biometrics

Park, Juhyuk,Youn, Jae Ryoun,Song, Young Seok American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.51

<P>Low electric energy loss is a very important problem to minimize the decay of transferred energy intensity due to impedance mismatch. This issue has been dealt with by adding an impedance matching layer at the interface between two media. A strategy was proposed to improve the charge transfer from the human body to a biometric device by using an impedance matching nanostructure. Nanocomposite pattern arrays were fabricated with shape memory polymer and carbon nanotubes. The shape recovery ability of the nanopatterns enhanced durability and sustainability of the structure. It was found that the composite nanopatterns improved the current transfer by two times compared with the nonpatterned composite sample. The underlying mechanism of the enhanced charge transport was understood by carrying out a numerical simulation. We anticipate that this study can provide a new pathway for developing advanced biometric devices with high sensitivity to biological information.</P>

Evaluation of effective thermal conductivity for carbon nanotube/polymer composites using control volume finite element method

Song, Young Seok,Youn, Jae Ryoun Elsevier 2006 Carbon Vol.44 No.4

<P><B>Abstract</B></P><P>Effective thermal conductivity of the polymeric composites filled with carbon nanotubes (CNTs) is predicted by using the asymptotic expansion homogenization technique (AEH), which makes it possible to localize and homogenize a heterogeneous medium. In the present study, CNT embedded epoxy composites are taken into account as the heterogeneous system. The representative volume element (RVE) employed in the homogenization process is constructed by assuming that the CNTs are dispersed homogeneously in the polymer matrix. It is presumed that the RVE contains a single CNT and that there is no direct interaction between neighboring CNTs. The dispersion state of CNTs in the composites is morphologically characterized by the field emission scanning electronic microscope (FESEM). In order to consider the orientation state of CNTs, the bounding approach is adopted by using the orientation tensor. It is found that the numerically homogenized thermal conductivity is higher than that obtained by the analytic model. Predicted conductivities are also compared with experimental results as well as analytic results. The homogenization technique yields the effective thermal conductivity accordant with experimental results. In the case that a heterogeneous material has anisotropic properties or geometrical complexity, the homogenization technique is an efficient method to obtain averaged material properties equivalent to those of the real heterogeneous medium.</P>