• Title, Summary, Keyword: type(${\alpha}$-2)

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Molecular Dynamic Simulations of the Phase Transition of $\alpha-quartz$ and $\alpha-quartz-type$-type $GeO_2$ under High Pressure (고압력하에서의 $\alpha-quartz$$\alpha-quartz$$GeO_2$의 상전이에 관한 분자동력학시뮬레이션)

  • ;;;;河村雄;Zenbe-e Nakagawa
    • Journal of the Korean Ceramic Society
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    • v.34 no.7
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    • pp.713-721
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    • 1997
  • Molecular dynamic (MD) simulations with new interatomic potential function including the covalent bond were performed on the phase transition of $\alpha$-quartz-type GeO2 under high pressure. The optimized crystal structure and the pressure dependence of the lattice constant showed higher reproducibility than the previous models and were in very good agreement with the experimental data. A phase transition of $\alpha$-quartz and $\alpha$-quartz-type GeO2 by simulation was found approximately 24 GPa and 6-7 GPa, respectively. This phase transition involved an abrupt volume shrinkage and showed 4-6 coordination mixed structure with the increasing in the coordination number of cation.

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ESTIMATES FOR RIESZ TRANSFORMS ASSOCIATED WITH SCHRÖDINGER TYPE OPERATORS

  • Wang, Yueshan
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.5
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    • pp.1117-1127
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    • 2019
  • Let ${\mathcal{L}}_2=(-{\Delta})^2+V^2$ be the $Schr{\ddot{o}}dinger$ type operator, where nonnegative potential V belongs to the reverse $H{\ddot{o}}lder$ class $RH_s$, s > n/2. In this paper, we consider the operator $T_{{\alpha},{\beta}}=V^{2{\alpha}}{\mathcal{L}}^{-{\beta}}_2$ and its conjugate $T^*_{{\alpha},{\beta}}$, where $0<{\alpha}{\leq}{\beta}{\leq}1$. We establish the $(L^p,\;L^q)$-boundedness of operator $T_{{\alpha},{\beta}}$ and $T^*_{{\alpha},{\beta}}$, respectively, we also show that $T_{{\alpha},{\beta}}$ is bounded from Hardy type space $H^1_{L_2}({\mathbb{R}}^n)$ into $L^{p_2}({\mathbb{R}}^n)$ and $T^*_{{\alpha},{\beta}}$ is bounded from $L^{p_1}({\mathbb{R}}^n)$ into BMO type space $BMO_{{\mathcal{L}}1}({\mathbb{R}}^n)$, where $p_1={\frac{n}{4({\beta}-{\alpha})}}$, $p_2={\frac{n}{n-4({\beta}-{\alpha})}}$.

The comparison of the output characteristics of 2-DOF PID controller in the multivariable flow control system with delayed time (지연시간을 갖는 다변수 유량제어 시스템의 2-자유도 PID 제어기 특성 비교)

  • Kim, Dong-Hwa
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.6
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    • pp.744-752
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    • 1999
  • In this paper, we studied the response characteristics of $\alpha$, $\beta$ separated type, combined type, PI typed, and feedforward type in 2DOF-PID controller through the simulation and the experiments designed with the multivariable flow control system. The parameters $\alpha$ and $\beta$ give an affect to characteristics of controller in separated type but $\gamma$ does not give an affect to the characteristics of 2-DOF PID. The more $\beta$ increases, the more overshoot decreases and especially, in case of PI type represent clearly. The $\alpha$, $\beta$ separated type has a very small overshoot and its magnitudes in 2-DOF PID onctroller increases in order of $\alpha$, $\beta$ combined type, PI type, feedforward type, conventional type. The response characteristics of simulation are similar to that of experiments but the experimental characteristics in the multivariable flow control system has the delayed response. The time delay of response in experiments depends on 2-DOF parameter $\alpha$, $\beta$, $\gamma$ and the overshoot increase as the $\alpha$, $\beta$, $\gamma$ increase. So, we can have a satisfactory response by tuning D gain.

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Association of Hepatocyte Nuclear Factor-$4{\alpha}$ (HNF-$4{\alpha}$) Polymorphisms (rs1884614) with Type 2 Diabetes in Korean Population

  • Kim, Su-Won;Yoo, Min
    • Biomedical Science Letters
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    • v.15 no.1
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    • pp.101-103
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    • 2009
  • The hepatocyte nuclear factor-$4{\alpha}$ (HNF-$4{\alpha}$), transcription factor involved in the regulation of serum lipid and glucose levels, has recently been reported to be associated with type 2 diabetes. Therefore, we investigated the genotype for the rs1884614 of HNF-$4{\alpha}$ gene in Korean population and compared genotype of patients with control group. 100 patients (Male 63, Female 37), who previously underwent type 2 diabetes (T2DM) and 100 controls (Male 36, Female 64) participated in this study. According to our present study there was no association between rs1884614 polymorphism in HNF-$4{\alpha}$ gene and T2DM in Koreans although other reports showed that HNF-$4{\alpha}$ polymorphisms might be associated with the pathogenesis of T2DM in Pima Indians et al. We assume that this finding should contribute to understanding of type 2 diabetes in Korean population in detail at genetic level.

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ISOTROPIC SMARANDACHE CURVES IN THE COMPLEX 4-SPACE

  • Ergut, Mahmut;Yilmaz, Suha;Unluturk, Yasin
    • Honam Mathematical Journal
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    • v.40 no.1
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    • pp.47-59
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    • 2018
  • We define the $e^{\alpha}_1e^{\alpha}_3$-isotropic Smarandache curves of type-1 and type-2, the $e^{\alpha}_1e^{\alpha}_2e^{\alpha}_3$-isotropic Smarandache curve, and the $e^{\alpha}_1e^{\alpha}_2e^{\alpha}_4$-isotropic Smarandache curves of type-1 and type-2. Then we examine these kinds of isotropic Smarandache curve according to Cartan frame in the complex 4-space $\mathbb{C}^4$ and give some differential geometric properties of these Samarandache curves.

COMPATIBLE MAPS OF TWO TYPES AND COMMON FIXED POINT THEOREMS ON INTUITIONISTIC FUZZY METRIC SPACE

  • Park, Jong-Seo
    • Honam Mathematical Journal
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    • v.32 no.2
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    • pp.283-298
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    • 2010
  • In this paper, we introduce the concept of compatible mapping of type(${\alpha}$-1) and type(${\alpha}$-2), prove the some properties and common fixed point theorem for such maps in intuitionistic fuzzy metric space. Also, we give the example. Our research are an extension for the results of Kutukcu and Sharma[3] and Park et.al.[11].

Expression of Low Voltage-Activated $Ca^{2+}$ Channels in Xenopus Oocytes

  • Lee, Jung-Ha;Han, Dong-Pyo
    • Journal of Microbiology and Biotechnology
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    • v.11 no.4
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    • pp.614-618
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    • 2001
  • Low-threshold T-type $Ca^{2+}$ channels are distinctive voltage-operated gates for external $Ca^{2+}$ entry around a resting membrane potential due to their low voltage activation. These phenomena have already been extensively studied due to their relevance in diverse physiological functions. Recently, three T-type $Ca^{2+}$ channel ${\alpha}$$_1$subunits were cloned and their biophysical properties were characterized after expression in mammalian expression systems. In this study, ${\alpha_IG} and {\alpha_IH}$ low-threshold $Ca^{2+}$ channels were expressed and characterized in Xenopus oocytes after adding 5' and 3'untranslated portions of a Xenopus ${\beta}$ globin to improve their expression levels. The added portions dramatically enhanced the expression levels of the ${\alpha_IG} and {\alpha_IH}$ T-type channels. When currents were recorded in 10 mM $Ba^{2+}$ as the charge carrier, the activation thresholds were about -60 mV, peak currents appeared at -20 mV, and the reversal potentials were between +40 and +45. The activation time constants were very similar to each other, while the inactivation time constants of the ${\alpha_IG}$ currents were smaller than those of ${\alpha_IH}$. Taken together, the electrophysiological properties of the ${\alpha_IG} and {\alpha_IH}$ channels expressed in Xenopus oocytes were similar to the previously reported characteristics of low-threshold $Ca^{2+}$ channel currents.

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Effects of Natural Product on the Inhibition of $5{\alpha}-Reductase$ Type 2 for the Development of Chemopreventive Agents in LNCaP Cells

  • Lee, Sung-Jin;Kim, Kyeong-Ho;Cho, Myung-Haing;Lee, Sang-Kook;Mar, Woong-Chon
    • Natural Product Sciences
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    • v.5 no.2
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    • pp.97-103
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    • 1999
  • The enzyme steroid $5{\alpha}-reductase$ is responsible for the conversion of testosterone into the most potent androgen dihydrotestosterone (DHT). In man, this steroid acts on a variety of androgen-responsive target tissues to mediate such diverse endocrine processes as male sexual differentiation in the fetus and prostatic growth in men. Androgen levels in the prostate may influence carcinogenesis in this organ. The use of a $5{\alpha}-reductase$ inhibitor, finasteride, in the chemoprevention of prostate cancer is being evaluated in a clinical trial and have been used successfully for treatment of benign prostatic hyperplasia. Therefore, for the discovery of $5{\alpha}-reductase$ type 2 inhibitors, we have evaluated the inhibitory effects of solvent fractionated extracts of natural products on $5{\alpha}-reductase$ type 2 activity. We have tested approximately 80 kinds of natural products after partition into n-hexane, ethyl acetate and aqueous layers from 100% methanol extracts of plants. The ethyl acetate fractions of Perilla sikokiana $(seed,\;IC_{50}\;:\;6.2\;ug/ml)$, Sophora flavescens $(root,\;IC_{50}\;:\;8.9\;ug/ml)$, and Angelica tenuissima $(root,\;IC_{50}\;:\;11.7\;ug/ml)$ revealed inhibitory effects on $5{\alpha}-reductase$ 2 activity in LNCaP cells. The effective ethyl acetate fractions of Perilla sikokiana, Sophora flavescens, Hydnocarpus anthelmintica, and Angelica tenuissima were subfractionated by column chromatography and tested. The subfractions $F4\;(IC_{50}\;:\;1.1\;ug/ml),\;F5\;(IC_{50}\;:\;2.0\;ug/ml),\;and\;F6\;(IC_{50}\;:\;5.8\;ug/ml)$ of the ethyl acetate fraction of Perilla sikokiana and the subfraction $F8\;(IC_{50}\;:\;5.3\;ug/ml)$ of the ethyl acetate fraction of Sophora flavescens displayed greater inhibition of $5{\alpha}-reductase$ type 2 than did finasteride in LNCaP cells. These active fractions are under the process of further sequential fractionation to find the effective pure compounds against $5{\alpha}-reductase$ 2 activity.

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An Endoplasmic Reticulum Cyclophilin Cpr5p Rescues Z-type α1-Antitrypsin from Retarded Folding

  • Jung, Chan-Hun;Lim, Jeong Hun;Lee, Kyunghee;Im, Hana
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2781-2786
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    • 2014
  • Human ${\alpha}_1$-antitrypsin (${\alpha}_1$-AT) is a natural inhibitor of neutrophil elastases and has several dozens of genetic variants. Most of the deficient genetic variants of human ${\alpha}_1$-AT are unstable and cause pulmonary emphysema. However, the most clinically significant variant, Z-type ${\alpha}_1$-AT, exhibits retarded protein folding that leads to accumulation of folding intermediates. These aggregate within the endoplasmic reticulum (ER) of hepatocytes, subsequently causing liver cirrhosis as well as emphysema. Here, we studied the role of an ER folding assistant protein Cpr5p on Z-type ${\alpha}_1$-AT folding. Cpr5p was induced > 2-fold in Z-type ${\alpha}_1$-AT-expressing yeast cells compared with the wild type. Knockout of CPR5 exacerbated cytotoxicity of Z-type ${\alpha}_1$-AT, and re-introduction of CPR5 rescued the knockout cells from aggravated cytotoxicity caused by the ${\alpha}_1$-AT variant. Furthermore, Cpr5p co-immunoprecipitated with Z-type ${\alpha}_1$-AT and facilitated its protein folding. Our results suggest that protein-folding diseases may be suppressed by folding assistant proteins at the site of causal protein biosynthesis.

THE ADHESION OF ODONTOBLAST TO TYPE I COLLAGEN (상아모세포의 I 형 아교질에 대한 부착)

  • Ahn, Myung-Ki;Jeong, Tae-Sung;Kim, Shin
    • THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
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    • v.37 no.3
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    • pp.308-316
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    • 2010
  • Odontoblasts are anchorage dependent cells adhering to a substrate via cell adhesive molecules. Receptor ligands such as integrins bind to these proteins and are known to function as signal transduction molecules in a series of critical recognition events of cell-substratum. The aim of this study is to examine the interaction of odontoblast (MDPC-23 cell) with type I Col and the effect of TGF-${\beta}1$ and TNF-$\alpha$ on the expression of cell adhesion molecules. In this study, MDPC-23 cells adhered to type I Col dose-dependently. Immunofluorescence data demonstrated that integrin ${\alpha}1$, ${\alpha}2$ and CD44 were expressed on cell surface, and FAK and paxillin were localized in focal adhesion plaques in MDPC-23 cells adhesion to Col. Cytokine TGF-${\beta}1$ increased the adhesion of MDPC-23 cells to Col and the expression level of integrin ${\alpha}1$, 4{\alpha}2$ and chondroitin sulfate on MDPC-23 cells. RT-PCR data demonstrated that cytokine TGF-${\beta}1$ increased the amount of integrin ${\alpha}1$ mRNA in MDPC-23 cells. Therefore, MDPC-23 cells adhere to collagen type I Col and expressed a complex pattern of integrins and proteoglycans, including ${\alpha}1$, ${\alpha}2$, chondroitin sulfate and CD44 detected by immunoblotting and immunofluorescence assay. TGF-${\beta}1$ treatment enhanced the expression of adhesion molecules such as integrin ${\alpha}1$, ${\alpha}2$ and chondroitin sulfate.