• BMB Reports
• /
• v.45 no.3
• /
• pp.141-146
• /
• 2012

Protein tyrosine phosphatase 1B (PTP1B) is important in the regulation of metabolic diseases and has emerged as a promising signaling target. Previously, we reported the PTP1B inhibitory activity of Rheum undulatum (RU). In the present study, we investigated the metabolic regulatory effects of RU in a high-fat diet (HFD) model. RU treatment significantly blocked body weight gain, which was accompanied by a reduction of feed efficiency. In addition, it led to a reduction of liver weight mediated by overexpression of PPAR${\alpha}$ and CPT1 in the liver, and an increase in the expression of adiponectin, aP2, and UCP3 in adipose tissue responsible for the reduction of total and LDL-cholesterol levels. Chrysophanol and physcion from RU significantly inhibited PTP1B activity and strongly enhanced insulin sensitivity. Altogether, our findings strongly suggest that 2 compounds are novel PTP1B inhibitors and might be considered as anti-obesity agents that are effective for suppressing body weight gain and improving lipid homeostasis.

• Journal of the Microelectronics and Packaging Society
• /
• v.11 no.3 s.32
• /
• pp.63-70
• /
• 2004

The structural, electrical properties of $(Ba, Sr)TiO_3[BSTO]/RuO_2$ thin films were examined by the addition of amorphous BSTO layer between crystlline BSTO film and $RuO_2$ substrate. We prepared BSTO films with double-layered structure, that is, amorphous layers deposited at $60^{\circ}C$ and crystalline films. Crystalline films were prepared at 550 on amorphous BSTO layer. The thickness of the amorphous layers was varied from 0 to 170 nm. During the deposition of crystalline films, the crystallization of the amorphous layers occurred and the structure was changed to circular while crystalline BSTO films showed columnar structure. Due to insufficient annealing effect, amorphous BSTO phase was observed when the thickness of the amorphous layers exceeded 30 nm. Amorphous BSTO layer could also prevent the formation of oxygen deficient region in $RuO_2$ surface. Leakage current of total BSTO films decreased with increasing amorphous layer thickness due to structural modifications. Dielectric constant showed maxi-mum value of 343 when amorphous layer thickness was 30 nm at which the improvement by grain growth and the degradation by amorphous phase were balanced.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.247-250
• /
• 2008

Biomass gasification is a promising technology for producing a fuel gas which is useful for power generation systems. In biomass gasification processes, tar formation often causes some problems such as pipeline plugging. Thus, proper tar treatment is necessary. So far, nickel (Ni)-based catalysts have been intensively studied for the catalytic tar removal. However, the deactivation of Ni-based catalysts takes place because of coke deposition and sintering of Ni metal particles. To overcome these problems, we have been using ruthenium (Ru)-based catalyst for tar removal. It is reported by Okada et al., that a Ru/$Al_2O_3$ catalyst is very effective for preventing the carbon deposition during the steam reforming of hydrocarbons. Also, this catalyst is more active than the Ni-based catalyst at a low steam to carbon ratio (S/C). Benzene was used for the tar model compound because it is the main constituent of biomass tar and also because it represents a stable aromatic structure apparent in tar formed in biomass gasification processes. The steam reforming process transforms hydrocarbons into gaseous mixtures constituted of carbon dioxide ($CO_2$), carbon monoxide (CO), methane ($CH_4$) and hydrogen ($H_2$).

• Analytical Science and Technology
• /
• v.8 no.4
• /
• pp.481-486
• /
• 1995

Quenching experiments by photoinduced electron transfer between a charged donor and a neutral acceptor were carried out in acetonitrile, dichloromethane and mixed solvents of acetonitrile and dichloromethane. Tris(2, 2'-bipyridine) ruthenium(II) ($[Ru(bpy)_3]^{2+}$) which has 2+ charge and dicyanobis (2, 2'-bipyridine) ruthenium(II) ($Ru(bpy)_2(CN)_2$) which has no charge were used as electron donors, and a series of tris(${\beta}$-diketonato) ruthenium (III) was used as acceptor. In dichloromethane, $[Ru(bpy)_3]^{2+}$ and its counter ions ($ClO{_4}^-$) form ion pair. In the estimate of ${\Delta}G$ of electron transfer, the electrostatic potential between counter ions and product ion pair produced by electron transfer must be taken into account. A similar effect of counter ions was found in mixed solvents of 10, 30, 50, 70 and 90% acetonitrile ratio in volume. The effect of counter ion on ${\Delta}G$ became smaller with the increase in acetonitrile ratio. The result in mixed solvents suggests that $[Ru(bpy)_3]^{2+}$ and its counter ions form ion pair even in 90% acetonitrile solution.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.11a
• /
• pp.52-52
• /
• 2003

Gbit급 DRAM 커패시터의 고유전물질로 각광받고 있는 (Ba,Sr)TiO$_3$〔BST〕의 하부전극 물질로서 (Ba,Sr)RuO$_3$〔BSR〕의 적용 가능성을 연구하였다. BSR은 BST와의 구조적, 화학적 유사성으로 인하여, BST와 하부전극사이의 저유전 계면반응 충의 생성을 최소화함으로서 향상된 전기적 특성을 구현 할 수 있다. 본 연구에서는 methoxyethoxytetramethylheptanedionate(METHD) 소스를 적용한 유기 화학 기상 증착법(MOCVD)법을 이용하여 BSR을 증착하였으며, 증착된 BSR의 특성을 x-ray photoelectron spectroscopy(XPS) 분석법으로 기화기 온도 변화에 따른 BSR박막의 특성을 분석하였다. 증착온도 55$0^{\circ}C$에서 소스의 기화효율에 영향을 미치는 기화기온도를 변화시켜가며 BSR박막의 증착실험을 진행하였으며 소스 유입 속도 0.075sccm, 증착 온도 55$0^{\circ}C$, Ar/O2 = 200/350 sccm일 때 기화기 온도를 260~28$0^{\circ}C$까지 1$0^{\circ}C$간격의 변화로 증착실험을 수행하였다.

• Journal of the Korean Physical Society
• /
• v.73 no.11
• /
• pp.1691-1697
• /
• 2018

Employing the density functional theory, we have investigated the roles of Coulomb and Hund's interactions in the electronic and magnetic properties of newly discovered ${\alpha}-RuCl_3$ having the $R{\overline{3}}$ symmetry, which is in close proximity of the Kitaev system. We show that both the size and the direction of local magnetic moment are highly dependent on Coulomb and Hund's interactions, and the spin and orbital parts show different behaviors. The validity of the so-called $j^{eff}$ picture is accessed upon interaction parameters, and the explicit roles of Hund's interaction in the local electronic structures and magnetic properties are discussed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.10a
• /
• pp.141-144
• /
• 2009

In this study, used simplest sandwich cells containing $Ru2^+$ liquid electrolytes in order to clarify the role of nanoporous $TiO_2$ electrodes. And, the cell structure is as follow: $F:SnO_2$ glass/ nanoporous $TiO_2$/ tris(2,2'-bipyridy)ruthenium(ll) colplex [$Ru(bpy)_3(PF_6)_2$] in acetonitrile/ $F:SnO_2$ glass. The result, we found that ECL intensities increased rapidly by use of cathodes with nanoporous $TiO_2$ layers. And, porous $TiO_2$ electrodes were confirmed to be efficient for ECL devices as well as solar cell devices. It is thought that the increases in the ECL intensities may be associated with both formation of $Ru^+$ in porous $TiO_2$ electrodes and the process taking place after reduction of $Ru^+$ which occurs in the nanoporous electrodes.

• Journal of the Korean Vacuum Society
• /
• v.8 no.3B
• /
• pp.333-339
• /
• 1999

$RuO_2$ thin films were prepared with various deposition conditions by rf magnetron sputtering. The films were annealed in vacuum, air, and air-vacuum, after that, the structural and electrical properties of the films were investigated. As the substrate temperature increases, the preferred orientation of the films changes from (101) to (200), and the grain size increases; especially, at $500^{\circ}C$, the size considerably increases. The preferred orientation of the films changes from (200) to (101) and the roughness of surface increase with the increase in oxygen partial pressure. The lowest value of resistivity of $RuO_2$ we prepared is $1.5\times 10^{-5}\Omega\codt\textrm{cm}$ at the conditions of $400^{\circ}C$ and 10% of oxygen partial pressure. After the processes of annealing, the films deposited at $400^{\circ}C$ and a oxygen partial pressure of 10% were relatively stable. The films deposited at $500^{\circ}C$ have denser structure and smoother surface when the films are annealed in vacuum after annealing in air.

• Journal of applied mathematics & informatics
• /
• v.12 no.1_2
• /
• pp.143-154
• /
• 2003

A finite group G is called (l, m, n)-generated, if it is a quotient group of the triangle group T(l, m, n) = 〈$\chi$, y, z│$\chi$$\^$l/ = y$\^$m/ = z$^n$ = $\chi$yz = 1〉. In [19], the question of finding all triples (l, m, n) such that non-abelian finite simple group are (l, m, n)-generated was posed. In this paper we partially answer this question for the sporadic group Ru. In fact, we prove that if p, q and r are prime divisors of │Ru│, where p < q < r and$.$(p, q) $\neq$ (2, 3), then Ru is (p, q, r)-generated.

• Journal of the Microelectronics and Packaging Society
• /
• v.2 no.1
• /
• pp.19-28
• /
• 1995

RuO2 함량을 각각 달리한 pyrochlore 구조의 Pb2Ru2O6.5분말을 제조하여 이 분말과 유기 vehicle 유기용매를 혼합하여 저항 페이스트를 제조한후 인쇄, 소결과정을 거쳐 전반적 인 물성을 분석하였고 두 종류의 페이스트에 TCR보정용 첨가제로서 ZrO2를 첨가한 경우 처가량에 따라 저항값은 크게 변화하였으나 TCR 은 약간의 변화를 보였으며 Nb2O5의 경우 저항값이 크게 증가하였으며 TCR은 2wt%까지 첨가시 매우 안정적인 값을 나타내었다. 고 정항의 경우 CuO의 첨가시 저항값이 크게 감소 하였으며 TCR은 첨가량에 따라 증가하였 으나 3wt%이상 첨가시 저항체 표면이 심하게 거칠어지는 결과를 보였다.