• 제목/요약/키워드: H&R

검색결과 14,197건 처리시간 0.039초

Protective Effect of Propofol against Hypoxia-reoxygenation Injury in HaCaT Human Keratinocytes

  • Kim, Yong-Ho;Kang, Jin-Mo;Kim, In-Ryoung;Lee, Bo-Young;Yoon, Ji-Young;Kim, Cheul-Hong;Park, Bong-Soo
    • International Journal of Oral Biology
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    • 제39권2호
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    • pp.97-105
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    • 2014
  • The aim of this study was to determine the beneficial effect of propofol on human keratinocytes that have undergone hypoxia reoxygenation (H/R) injury and to investigate whether autophagy is associated with the protective mechanism. Thus, we evaluated how propofol influences the intracellular autophagy and apoptosis during the H/R process in the HaCaT cells. The cultured human keratinocyte cells were exposed to 24 h of hypoxia (5% $CO_2$, 1% $O_2$, 94% $N_2$) followed by 12 h of reoxygenation (5% $CO_2$, 21% $O_2$, 74% $N_2$). The experiment was divided into 4 groups: (1) Control=Normoxia ; (2) H/R=Hypoxia Reoxygenation ; (3) PPC+H/R=Propofol Preconditioning+Hypoxia Reoxygenation; (4) 3-MA+PPC+ H/R=3-MA-Methyladenine+Propofol Preconditioning+ Hypoxia Reoxygenation. In addition, Western blot analysis was performed to identify the expression of apoptotic pathway parameters, including Bcl-2, Bax, and caspase 3 involved in mitochondrial-dependent pathway. Autophagy was determined by fluorescence microscopy, MDC staining, AO staining, and western blot. The H/R produced dramatic injuries in keratinocyte cells. In our study, the viability of Propofol in H/R induced HaCaT cells was first studied by MTT assay. The treatment with 25, 50, and $100{\mu}M$ Propofol in H/R induced HaCaT cells enhanced cell viability in a dose-dependent manner and $100{\mu}M$ was the most effective dose. The Atg5, Becline-1, LC3-II, and p62 were elevated in PPC group cells, but H/R-induced group showed significant reduction in HaCaT cells. The Atg5 were increased when autophagy was induced by Propofol, and they were decreased when autophagy was suppressed by 3-MA. These data provided evidence that propofol preconditioning induced autophagy and reduced apoptotic cell death in an H/R model of HaCaT cells, which was in agreement with autophagy playing a very important role in cell protection.

Amine and Olefin Complexes of Pt(II) Having a PCP-Pincer Ligand

  • Park, Soon-Heum
    • Bulletin of the Korean Chemical Society
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    • 제23권1호
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    • pp.132-136
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    • 2002
  • $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)\;(OTf=CF_3SO_3^-)$ readily reacts with various amines to afford cationic amine complexes $[Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(amine)](OTf)\;(amine=NH_3,\;NHMe_2,\;NHC_4H_8,\;NH_2Ph,\;NH_2(Tol-p))$ in high yields. These complexes have been fully characterized by IR, $^1H-,\;^{19}F{^1H}-,\;and\;^{31}P{^1H}-NMR$ spectroscopy, and elemental analyses. Reaction of $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)$ with acrylonitrile quantitatively produced the ${\pi}$-olefinic complex $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(CH_2=CHCN)](OTf)$ which is only stable in solution in the presence of acrylonitrile. Attempt at isolating this complex in the pure solid state was failed due to partial decomposition into $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)$ The equilibrium constants $(K_{eq}=[Pt(PCP)-(NH_2R)^+][CH_2=CHCN]/[Pt(PCP)(CH_2=CHCN)^+][NH_2R]:\;[Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(CH_2=CHCN)]^++NH_2R{\rightleftarrows}[Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(NH_2R)]^++CH_2=CHCN=Ph,\;p-tolyl)$ were calculated to be 0.28 (for R = Ph) and 3.1 (R = p-tolyl) at $21^{\circ}C$. The relative stability of the ${\sigma}$-donor amine versus the ${\pi}$-olefinic acrylonitrile complex has been found largely dependent upon the amine-basicity $(pK_b)$, implicating that acrylonitrile practically competes with amine in the platinum coordination sphere. On the contrary to the formation of the acrylonitrile complex, no reaction of $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)$ with other olefins such as ethylene, styrene and methyl acrylate was observed.

핸드오프를 지원하는 H.323 게이트키퍼 구조 (An H.323 Gatekeeper Architecture Providing Handoff function)

  • 이영신;최기무;강환종
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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    • pp.341-344
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    • 2001
  • H.323 proposes to use Mobile IP and H.323 ad hoc conference signaling to provide Handoff function to an H.323 mobile terminal. But the H.323 ad hoc conference signaling has a drawback. It requires an H.323 terminal to do a complex conference signaling which takes a longer signaling time. In this paper, we propose an GK architecture that provides Handoff function effectively using 3$^{rd}$ P'||'||'||'||'||'&'||'||'||'||'||'R(Third party initiated Pause and Rerouting) signaling which are done through H.245 logical channel. The GK which is implementing 3$^{rd}$ P'||'||'||'||'||'&'||'||'||'||'||'R signaling only requires an H.323 endpoint to do the H.323 basic signaling in reestablishing media channel and gives the faster Handoff signaling. To do this, our GK has derived H.245 control channel using tunneling f3r all H.323 calls including the fast connect calls which enable terminals communicate each other if they doesn't have H.245 control channel .municate each other if they doesn't have H.245 control channel .

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ON THE SUPERSTABILITY OF SOME FUNCTIONAL INEQUALITIES WITH THE UNBOUNDED CAUCHY DIFFERENCE (x+y)-f(x)f(y)

  • Jung, Soon-Mo
    • 대한수학회논문집
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    • 제12권2호
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    • pp.287-291
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    • 1997
  • Assume $H_i : R_+ \times R_+ \to R_+ (i = 1, 2)$ are monotonically increasing (in both variables), homogeneous mapping for which $H_1(tu, tv) = t^p(H_1(u, v) (p > 0)$ and $H_2(u, v)^{t^q} (q \leq 1)$ hold for $t, u, v \geq 0$. Using an idea from the paper of Baker, Lawrence and Zorzitto [2], the superstability problems of the functional inequalities $\Vert f(x+y) - f(x)f(y) \Vert \leq H_i (\Vert x \Vert, \Vert y \Vert)$ shall be investigated.

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EXISTENCE OF RESONANCES FOR DIFFERENTIAL OPERATORS

  • Kim, In-Suk
    • 대한수학회논문집
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    • 제9권2호
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    • pp.337-353
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    • 1994
  • Let H be a Schrodinger operator in $L^2$(R) H =(equation omitted) + V(x), with supp V ⊂ [-R, R]. A number $z_{0}$ / in the lower half-plane is called a resonance for H if for all $\phi$ with compact support 〈$\phi$, $(H - z)^{-l}$ $\phi$〉 has an analytic continuation from the upper half-plane to a part of the lower half-plane with a pole at z = $z_{0}$ . Thus a resonance is a sort of generalization of an eigenvalue. For Im k > 0, ($H - k^2$)$^{-1}$ is an integral operator with kernel, given by Green's function(omitted)

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PROJECTION PROCESSES OF H-SSSIS RANDOM FIELDS

  • Kim, Joo-Mok
    • 충청수학회지
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    • 제9권1호
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    • pp.115-121
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    • 1996
  • Let $\{X(t);\;t{\in}R^n\}$ be a measurable, separable and H-sssis random fields. Here, we suppose that the increments are invariant under all Euclidean rigid body motions. We investigate some properties of H-sssis random fields and monotonicity of projection process $\{X_e(t);\;t{\in}R^1\}$ in any direction $e{\in}R^n$.

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HOMOCLINIC ORBITS FOR HAMILTONIAN SYSTEMS

  • Kim, June-Gi
    • 대한수학회보
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    • 제32권1호
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    • pp.1-11
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    • 1995
  • Let $p, q \in R^2 and H : R^{2n} \to R^n$ be differentiable. An autonomous Hamiltonian system has the form $$ (0.1) \dot{p} = -\frac{\partial q}{\partial H}(p, q), \dot{q} = \frac{\partial p}{\partial H}(p, q) $$.

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