• 대한수학회논문집
• /
• 제38권4호
• /
• pp.1215-1231
• /
• 2023

The present article contains the study of D-homothetically deformed f-Kenmotsu manifolds. Some fundamental results on the deformed spaces have been deduced. Some basic properties of the Riemannian metric as an inner product on both the original and deformed spaces have been established. Finally, applying the obtained results, soliton functions, Ricci curvatures and scalar curvatures of almost Riemann solitons with several kinds of potential vector fields on the deformed spaces have been characterized.

• BMB Reports
• /
• 제44권8호
• /
• pp.506-511
• /
• 2011

Mammalian Target of Rapamycin (mTOR) is a serine/threonine kinase and that forms two multiprotein complexes known as the mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). mTOR regulates cell growth, proliferation and survival. mTORC1 is composed of the mTOR catalytic subunit and three associated proteins: raptor, mLST8/$G{\beta}L$ and PRAS40. mTORC2 contains mTOR, rictor, mLST8/$G{\beta}L$, mSin1, and protor. Here, we discuss mTOR as a promising anti-ischemic agent. It is believed that mTORC2 lies down-stream of Akt and acts as a direct activator of Akt. The different functions of mTOR can be explained by the existence of two distinct mTOR complexes containing unique interacting proteins. The loss of TSC2, which is upstream of mTOR, activates S6K1, promotes cell growth and survival, activates mTOR kinase activities, inhibits mTORC1 and mTORC2 via mTOR inhibitors, and suppresses S6K1 and Akt. Although mTOR signaling pathways are often activated in human diseases, such as cancer, mTOR signaling pathways are deactivated in ischemic diseases. From Drosophila to humans, mTOR is necessary for Ser473 phosphorylation of Akt, and the regulation of Akt-mTOR signaling pathways may have a potential role in ischemic disease. This review evaluates the potential functions of mTOR in ischemic diseases. A novel mTOR-interacting protein deregulates over-expression in ischemic disease, representing a new mechanism for controlling mTOR signaling pathways and potential therapeutic strategies for ischemic diseases.

• 한국전산구조공학회논문집
• /
• 제24권5호
• /
• pp.577-588
• /
• 2011

본 논문은 복합 불연속면을 갖는 포텐셜 문제의 해석을 위해 확장된 MLS(Moving Least Squares) 차분법을 제시한다. 계면경계를 따라 해(solution)와 수직방향, 접선방향 미분들이 모두 불연속 특이성을 나타내는 복합 불연속면을 묘사하기 위해 계단함수, 쐐기함수, 가위함수와 같은 불연속 특이함수를 추가하여 기존의 MLS 차분법을 개선했다. 계면경계조건은 기지의 조건으로서 지배방정식의 이산화과정에서 추가의 미지계수를 발생시키지 않는다. 포아송 방정식 형태의 지배미분 방정식을 풀기 위해 내부영역과 경계에 절점을 배치하고 차분식을 구성한다. 차분식을 조립한 계 방정식을 직접 풀기 때문에 계산효율성이 매우 우수하다. 수치예제는 제시된 해석기법의 우수성을 잘 보여주며, 균열전파, 이동경계, 상호작용 문제 등 다양한 불연속 문제로의 확장이 기대된다.

• 조명전기설비학회논문지
• /
• 제20권4호
• /
• pp.29-36
• /
• 2006

본 논문은 여러 가지 형상의 접지시스템에서 접지전극 상호간의 전위간섭에 대해 다루었다. 접지전극의 일정한 형상과 크기, 접지전극간 이격거리에 따른 전위상승과 전위간섭계수를 수조실험장치를 이용하여 측정하고, CDEGS 프로그램으로 해석하였다. 전위상승과 전위간섭계수는 접지전극의 이격거리, 접지전극의 형상과 크기에 강하게 의존한다. 격자형 접지전극과 격자형 접지전극 사이의 전위간섭은 격자형 접지전극과 봉형 접지전극 사이의 전위간섭보다 낮은 것으로 나타났다.

• Molecules and Cells
• /
• 제38권7호
• /
• pp.657-662
• /
• 2015

Rapid and efficient engulfment of apoptotic cells is an essential property of phagocytes for removal of the large number of apoptotic cells generated in multicellular organisms. To achieve this, phagocytes need to be able to continuously uptake apoptotic cells. It was recently reported that uncoupling protein 2 (Ucp2) promotes engulfment of apoptotic cells by increasing the phagocytic capacity, thereby allowing cells to continuously ingest apoptotic cells. However, the functions of Ucp2, beyond its possible role in dissipating the mitochondrial membrane potential, that contribute to elevation of the phagocytic capacity have not been determined. Here, we report that the anion transfer or nucleotide binding activity of Ucp2, as well as its dissipation of the mitochondrial membrane potential, is necessary for Ucp2-mediated engulfment of apoptotic cells. To study these properties, we generated Ucp2 mutations that affected three different functions of Ucp2, namely, dissipation of the mitochondrial membrane potential, transfer of anions, and binding of purine nucleotides. Mutations of Ucp2 that affected the proton leak did not enhance the engulfment of apoptotic cells. Although anion transfer and nucleotide binding mutations did not affect the mitochondrial membrane potential, they exerted a dominant-negative effect on Ucp2-mediated engulfment. Furthermore, none of our Ucp2 mutations increased the phagocytic capacity. We conclude that dissipation of the proton gradient by Ucp2 is not the only determinant of the phagocytic capacity and that anion transfer or nucleotide binding by Ucp2 is also essential for Ucp2-mediated engulfment of apoptotic cells.

• Bulletin of the Korean Chemical Society
• /
• 제30권6호
• /
• pp.1309-1312
• /
• 2009

Surface potential and growth processes of hexadecanethiol (HDT) self-assembled monolayers (SAMs) on Au(111) surfaces were examined by Kelvin probe method and scanning tunneling microscopy. It was found that surface potential strongly depends on surface structure of HDT SAMs. The surface potential shift for the striped phase of HDT SAMs chemisorbed on Au(111) surface was +0.45 eV, which was nearly the same as that of the flat-lying hexadecane layer physisorbed on Au(111) surface. This result indicates that the interfacial dipole layer induced by adsorption of alkyl chains is a main contributor to the surface potential change. In the densely-packed HDT monolayer, further change of the surface potential was observed, suggesting that the dipole moment of the alkanethiol molecules is an origin of the surface potential change. These results indicate that the work function of a metal electrode can be modified by controlling the molecular orientation of an adsorbed molecule.

• 한국정밀공학회지
• /
• 제20권7호
• /
• pp.208-216
• /
• 2003

In this paper, a two-dimensional electroelastic analysis is performed on a piezoelectric material with an open crack. The approach of Lekhnitskii's complex potential functions is used in the derivation and Bueckner's weight function theory is extended to piezoelectric materials. The stress intensity factors and the electric displacement intensity factor are calculated by the weight function theory.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
• /
• pp.41-44
• /
• 1989

This paper describes an analysis of the three-dimensional eddy current problems by the finite element method using magnetic vector potential and electric scalar potential. The finite element formulation uses first-order shape functions and tetrahedral elements. The validity of this formalation is ensured as the result of the sphere conductor model problem in a sinusoidal magnetic field.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집A
• /
• pp.628-635
• /
• 2001

Hydrodynamic behavior and response of vertical-cylindrical liquid-storage tank is considered. The equation of the liquid motion is shown by Laplace's differential equation with the fluid velocity potential. The solution of the Laplace's differential equation of the liquid motion is expressed with the modified Bessel functions. Only rigid tank is studied. The effective masses and heights for the tank contents are presented for engineering design model.

• 한국안전학회지
• /
• 제8권4호
• /
• pp.101-106
• /
• 1993

The streaming current of insulating oil increases with increasing oil velocity and oil amount, A contact potential difference as an energetic state exits in the polymer thin film, both sides of which are contacted by two different metals having different work functions. Accordingly, the potential difference may be a cause for the short circuited transient current flowing through the external circuit. The polymers are electrificated as the electric field Is supplied, and the currents flow with increasing temperature.