• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.21-21
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• 1996

The hyperthermostable protein, rubredoxin from Pyrococcus furiosus is 53-residue protein with a three-stranded anti-parallel $\beta$-sheet and several loops. To investigate the effect of changes of electrostatic and hydrophobic interactions on the structure and dynamic property of P. furiosus rubredoxin, molecular dynamics simulations in water were performed on three mesophilic rubredoxins, P, furiosus rubresoxin, and 5 mutants of P. furiosus rubredoxin. (omitted)

• Korean Journal of Mathematics
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• v.19 no.1
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• pp.61-64
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• 2011

Let $\mathcal{A}^*$ denotes the class of operators satisfying $|T^2|{\geq}|T^*|^2$. In this paper, we show if the restriction to a non-trivial invariant subspace $\mathcal{M}$ of an operator $T{\in}\mathcal{A}^*$ is normal, then $\mathcal{M}$ reduces T.

• Korean Journal of Mathematics
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• v.16 no.3
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• pp.349-353
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• 2008

Let the set of all quasi-class A operators for which $ker(A){\subseteq}ker(A^*)$ be denoted by $A{\in}{\mathcal{Q}}A^*$. In this paper it is proved that an operator $T{\in}{\mathcal{Q}}A^*$ is normal if and only if the Duggal transform of T is normal.

• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.499-507
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• 2010

In this note, we study the local spectral properties of semi-shifts. If $T\;{\in}\;L(X)$ is a semi-shift on a complex Banach space X, then T is admissible. We also prove that if $T\;{\in}\;L(X)$ is subadmissible, then $X_T(F)\;=\;E_T(F)$ for all closed $F\;{\subseteq}\;\mathbb{C}$. In particular, every subscalar operator on a Banach space is admissible.

• Journal of the Korean Mathematical Society
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• v.53 no.1
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• pp.233-246
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• 2016

In this paper, we introduce the class of analytic extensions of M-hyponormal operators and we study various properties of this class. We also use a special Sobolev space to show that every analytic extension of an M-hyponormal operator T is subscalar of order 2k + 2. Finally we obtain that an analytic extension of an M-hyponormal operator satisfies Weyl's theorem.

• IMMUNE NETWORK
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• v.14 no.1
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• pp.45-53
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• 2014

Osteoarthritis (OA) is a degenerative joint disease characterized by a progressive loss of cartilage. And, increased oxidative stress plays a relevant role in the pathogenesis of OA. Ursodeoxycholic acid (UDCA) is a used drug for liver diseases known for its free radical-scavenging property. The objectives of this study were to investigate the in vivo effects of UDCA on pain severity and cartilage degeneration using an experimental OA model and to explore its mode of actions. OA was induced in rats by intra-articular injection of monosodium iodoacetate (MIA) to the knee. Oral administration UDCA was initiated on the day of MIA injection. Limb nociception was assessed by measuring the paw withdrawal latency and threshold. Samples were analyzed macroscopically and histologically. Immunohistochemistry was used to investigate the expression of interleukin-$1{\beta}$ (IL-$1{\beta}$), IL-6, nitrotyrosine and inducible nitric oxide synthase (iNOS) in knee joints. UDCA showed an antinociceptive property and attenuated cartilage degeneration. OA rats given oral UDCA significantly exhibited a decreased number of osteoclasts in subchondral bone legion compared with the vehicle-treated OA group. UDCA reduced the expression of IL-$1{\beta}$, IL-6, nitrotyrosine and iNOS in articular cartilage. UDCA treatment significantly attenuated the mRNA expression of matrix metalloproteinase-3 (MMP-3), -13, and ADAMTS5 in IL-$1{\beta}$-stimulated human OA chondrocytes. These results show the inhibitory effects of UDCA on pain production and cartilage degeneration in experimentally induced OA. The chondroprotective properties of UDCA were achieved by suppressing oxidative damage and inhibiting catabolic factors that are implicated in the pathogenesis of cartilage damage in OA.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.590-597
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• 2000

The rheological properties of ${\beta}-glucans$ isolated from non-waxy and waxy barley were investigated. ${\beta}-Glucan$ solutions showed pseudoplastic properties and their behaviors were explained by applying Power law model in the range of concentrations$(1{\sim}4%)$ and temperatures$(20{\sim}65^{\circ}C)$. The effects of temperature and concentration on the apparent viscosity at $700\;s^{-1}$ shear rate were examined by applying Arrhenius equation and power law equation, and their effect was more pronounced in waxy ${\beta}-glucan$ solutions. The activation energy for flow of ${\beta}-glucan$ solutions decreased with the increase of concentration, and the concentration-dependent constant A increased with the increase of temperature. The intrinsic viscosity of waxy ${\beta}-glucan$ was higher than that of non-waxy ${\beta}-glucan$. The transition from dilute to concentrate region occurred at a critical coil overlap parameter $C^*[{\eta}]=0.02.$ The slopes of non-waxy and waxy ${\beta}-glucan$ at $C[{\eta}] were similar, but the slope of waxy ${\beta}-glucan$ at $C[{\eta}]>C^*[{\eta}]$ was higher than that of non-waxy ${\beta}-glucan$. Dynamic viscoelasticity measurement showed that cross-over happened, and storage modulus was higher than loss modulus at frequency range above cross-over. ${\beta}-Glucan$ solutions formed weak gels after stored for 24 hr.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.347-354
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• 2014

Larrea nitida is a plant that belongs to the Zygophyllaceae family and is widely used in South America to treat inflammatory diseases, tumors and menstrual pain. However, its pharmacological activity remains unclear. In this study we evaluated the property of selective estrogen receptor modulator (SERM) of Larrea nitida extracts (LNE) as a phytoestrogen that can mimic, modulate or disrupt the actions of endogenous estrogens, depending on the tissue and relative amount of other SERMs. To investigate the property of SERM of LNE, we performed MCF-7 cell proliferation assays, estrogen response element (ERE)-luciferase reporter gene assay, human estrogen receptor (hER) binding assays and in vivo uterotrophic assay. To gain insight into the active principles, we performed a bioassay-guided analysis of LNE employing solvents of various polarities and using classical column chromatography, which yielded 16 fractions (LNs). LNE showed high binding affinities for $hER{\alpha}$ and $hER{\beta}$ with $IC_{50}$ values of $1.20{\times}10^{-7}$ g/ml and $1.00{\times}10^{-7}$ g/ml, respectively. LNE induced $17{\beta}$-estradiol (E2)-induced MCF-7 cell proliferation, however, it reduced the proliferation in the presence of E2. Furthermore, LNE had an atrophic effect in the uterus of immature rats through reducing the expression level of progesterone receptor (PR) proteins. LN08 and LN10 had more potent affinities for binding on $hER{\alpha}$ and ${\beta}$ than other fractions. Our results indicate that LNE had higher binding affinities for $hER{\beta}$ than $hER{\alpha}$, and showed SERM properties in MCF-7 breast cancer cells and the rat uterus. LNE may be useful for the treatment of estrogen-related conditions, such as female cancers and menopause.

• Journal of Korea Technology Innovation Society
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• v.11 no.2
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• pp.241-263
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• 2008

Within any income approach, a discount rate is used to convert some projected free cash flow to its presented value. In case of valuing companies, the most frequently used discount rate is the weighted average cost of capital(WACC) at the aggregate level. But technology valuation is different to discounting aggregate corporate cash flow since it is concerned about individual Intellectual property. Therefore, blindly applying standard discount rate such as WACC in technology valuation is unlikely to lead to the right result. The primary focus of this paper is to establish the structure of discount rate for technology valuation and to suggest the method of estimation. To determine an appropriate discount rate for technology valuation, the level of technology risk, market risk and competitive risk should be included in the structure of discount rate. This paper suggests the build-up model which consists of three components as a expansion of the CAPM. It includes (1) a risk-free rate of return, (2) general market risk premium and beta and (3) intellectual property risk premium related to technology risk and specific target market risk. However, there is no specific check list for examining the intellectual property risk until now and no specific method for quantifying its risk into risk premium. This paper developed the 10 element to determine the level of the intellectual property risk and applied estimation function such as linear function, natural log function and exponential function to transform the level of risk into risk premium. The limitation of this paper is that the range of intellectual property risk premium is inferred based on the information of foreign and domestic valuation agency. Finally, this paper explored the development of an intellectual property discount rate for technology valuation and presented the method in order to quantify the intellectual property risk premium.

• The Korea Journal of Herbology
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• v.23 no.3
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• pp.93-102
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• 2008

Objectives : Forsythiae Fructus (Forsythia koreana Nakai) has been used anti-inflammatory, diuretics, antidote, and antibacterials in traditional herbal medicine. The present study is focused on the inhibitory effect of Forsythiae Fructus ethanol extract (FF-E) on the production of inflammatory mediators such as NO, iNOS and proinflammatory cytokines ($TNF-{\alpha}$, $IL-1{\beta}$ and IL-6) in LPS-stimulated BV-2 cells, a mouse microglial cell line, and investigated the scavenging activity of FF-E. Methods : BV-2 cells were pre-incubated with FF-E for 30 min and then stimulated with LPS (1 ${\mu}g/m{\ell}$) at indicated times. Cell toxicity of GCF was determined by MTT assay. The levels of NO, PGE2 and cytokines were measured by Griess assay and ELISA. The mRNA and protein expressions of iNOS and cytokines were determined by RT-PCR and Western blotting. Free radical scavenging activity of GCF was determined by DPPH assay in tube test. Results : FF-E significantly inhibited the excessive production of NO, $PGE_2$, $TNF-{\alpha}$, and $IL-1{\beta}$ in LPS-stimulated BV-2 cells. In addition, FF-E attenuated the mRNA and protein expressions of iNOS, and proinflammatory cytokines. FF-E also significantly scavenged the DPPH free radicals in a dose-dependent manner. Conclusions : These results indicate that FF-E exhibits anti-inflammatory property by suppressing the transcription of inflammatory mediator genes, suggesting the anti-inflammatory property of FF-E may make it useful as a therapeutic agent for the treatment of human neurodegenerative diseases.