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Search Results: 1 - 10 of 169 matches for " Kiyomi Kakiuchi "
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Design and Molecular Docking Study of Antimycin A3 Analogues as Inhibitors of Anti-Apoptotic Bcl-2 of Breast Cancer  [PDF]
Ade Arsianti,   Fadilah,   Kusmardi, Hiroki Tanimoto, Tsumoru Morimoto, Kiyomi Kakiuchi
Open Journal of Medicinal Chemistry (OJMC) , 2014, DOI: 10.4236/ojmc.2014.43006
Abstract: In this paper, we report the design and moleculardocking study of analogues of antimycin A3 as inhibitors of anti-apoptotic Bcl-2 of breast cancer. Twenty designed compounds and the original antimycin A3 were docked based on their interaction with breast tumor receptor binding target Bcl-2. The docking resulted in the five top-ranked compounds, namely, compounds 11, 14, 15, 16, and 20, which have a lower \"\"G binding energy, better affinity and stronger hydrogen bonding interactions to the active site of Bcl-2 than antimycin A3. Among those five top-ranked compounds, analogue compounds 11 and 14, which have an 18-membered tetralactone core and 18-membered tetraol core, respectively, exhibited the strongest hydrogen bond interaction, formed high stability conformation, and demonstrated the greatest inhibitory activity on the catalytic site of Bcl-2.
Diastereoselective [2+2] Photocycloaddition of Chiral Cyclic Enones with Olefins in Aqueous Media Using Surfactants
Yasuhiro Nishiyama,Mikiko Shibata,Takuya Ishii,Tsumoru Morimoto,Hiroki Tanimoto,Ken Tsutsumi,Kiyomi Kakiuchi
Molecules , 2013, DOI: 10.3390/molecules18021626
Abstract: We conducted diastereodifferentiating [2+2] photocycloadditions of cyclo-hexenones modified with a chiral 8-( p-methoxy phenyl)menthyl auxiliary with olefins in water. Although the photoreaction didn’t proceed at all in pure water owing to very low solubility, the use of surfactants [sodium dodecyl sulfate (SDS) or dodecylamine hydrochloride (DAH)] and additive (organic solvent) enabled the reactions to progress with moderate to high conversions and yields. Furthermore, we synthesized a new menthol derivative substrate containing a ( p-octyloxy)phenyl group for enhancing hydrophobicity, and elucidated that this new substrate was found to be a suitable chiral auxiliary in this asymmetric photoreaction in aqueous system. The additive effect of organic molecules on the yield and diastereoselectivity of the photo-adducts is also discussed.
Plateau of the Magnetization Curve of the S=1/2 Ferromagnetic-Ferromagnetic-Antiferromagnetic Spin Chain
Kiyomi Okamoto
Physics , 1995, DOI: 10.1016/0038-1098(96)00007-5
Abstract: I analytically study the plateau of the magnetization curve at $M/M_{\rm S} = 1/3$ (where $M_{\rm S}$ is the saturation magnetization) of the one-dimensional $S=1/2$ trimerized Heisenberg spin system with ferromagnetic ($J_{\rm F}$)-ferromagnetic ($J_{\rm F}$)-antiferromagnetic ($J_{\rm A}$) interactions at $T=0$. I use the bosonization technique for the fermion representation of the spin Hamiltonian through the Jordan-Wigner transformation. The plateau appears when $\gamma \equiv J_{\rm F}/J_{\rm A} \allowbreak < \gamma_{\rm C}$, and vanishes when $\gamma > \gamma_{\rm C}$, where the critical value $\gamma_{\rm C}$ is estimated as $\gamma_{\rm C} = 5 \sim 6$. The behavior of the width of the plateau near $\gamma_{\rm C}$ is of the Kosterlitz-Thouless type. The present theory well explains the numerical result by Hida.
Critical Properties of the transition between the Haldane phase and the large-D phase of the spin-1/2 ferromagnetic-antiferromagnetic Heisenberg chain with on-site anisotropy"
Kiyomi Okamoto
Physics , 1995, DOI: 10.1088/0305-4470/29/8/012
Abstract: We analytically study the ground-state quantum phase transition between the Haldane phase and the large-$D$ (LD) phase of the $S=1/2$ ferromagnetic-antiferromagnetic alternating Heisenberg chain with on-site anisotropy. We transform this model into a generalized version of the alternating antiferromagnetic Heisenberg model with anisotropy. In the transformed model, the competition between the transverse and longitudinal bond alternations yields the Haldane-LD transition. Using the bosonization method, we show that the critical exponents vary continuously on the Haldane-LD boundary. Our scaling relations between critical exponents very well explains the numerical results by Hida.
Inversion Phenomena of the Anisotropies of the Hamiltonian and the Wave Function in Quantum Spin Chains
Kiyomi Okamoto
Physics , 2013, DOI: 10.7566/JPSCP.1.012025
Abstract: We investigate the inversion phenomena between the XXZ anisotropies of the Hamiltonian and the wave function in quantum spin chains. We focus on the S=1/2 geometrically frustrated 3-leg ladder system with the XXZ interaction anisotropy. By use of the degenerate perturbation theory from the strong rung coupling limit, we have obtained the ground-state phase diagram. In some parameter regions, the Tomonaga-Luttinger spin liquid state is realized in spite of the Ising-like anisotropy, and the Neel state in spite of the XY-like anisotropy.
Level Spectroscopy: Physical Meaning and Application to the Magnetization Plateau Problems
Kiyomi Okamoto
Physics , 2002, DOI: 10.1143/PTPS.145.113
Abstract: We review the level spectroscopy, which is a powerful method of analyzing the numerical data with respect to the Berezinskii-Kosterlitz-Thouless quantum phase transition in one dimension. We focus on its physical meaning and also its application to the magnetization plateau problems.
Anisotropies of the Hamiltonian and the Wave Function: Inversion Phenomena in Quantum Spin Chains
Kiyomi Okamoto
Physics , 2002, DOI: 10.1143/PTPS.145.208
Abstract: We investigate the inversion phenomenon between the XXZ anisotropies of the Hamiltonian and the wave function in quantum spin chains, mainly focusing on the S=1/2 trimerized XXZ model with the next-nearest-neighbor interactions. We have obtained the ground-state phase diagram by use of the degenerate perturbation theory and the level spectroscopy analysis of the numerical data calculated by the Lanczos method. In some parameter regions, the spin-fluid is realized for the Ising-like anisotropy, and the Neel state for the XY-like anisotropy, against the ordinary situation.
Randomness Effect on the Temperature Dependence of the Finite Field Magnetization of a One-Dimensional Spin Gapped System
Kiyomi Okamoto
Physics , 2013, DOI: 10.7566/JPSCP.4.013003
Abstract: We investigate the temperature dependence of the finite-field magnetization of the S=1/2 bond-alternating XY model in the Random magnetic field along the z-direction having the Lorentzian distribution. The random-averaged free energy can be exactly calculated, which enables us to obtain the thermodynamical quantities. The temperature dependence of the finite-field magnetization shows various behaviors depending on the parameters $\delta$ and $\Gamma$, where $\delta$ and $\Gamma$ are the bond-alternation parameter and the Lorentzian distribution parameter, respectively.
THR0921, a novel peroxisome proliferator-activated receptor gamma agonist, reduces the severity of collagen-induced arthritis
Tetsuya Tomita, Yoshimi Kakiuchi, Philip S Tsao
Arthritis Research & Therapy , 2005, DOI: 10.1186/ar1856
Abstract: Rheumatoid arthritis (RA) is characterized by a chronic Th-1 associated inflammatory process resulting in systemic immunological abnormalities and progressive joint destruction. Although the precise etiology and underlying mechanisms of RA remain to be elucidated, several mediators, and thus potential therapeutic targets, have emerged. Proinflammatory cytokines such as tumor necrosis factor (TNF)-α and IL-1β play a key role affecting the imbalance between Th1 and Th2 cells, as well as the activation of other cytokines, chemokines and proteinases [1-5]. In addition, recent evidence indicates that osteoclasts may participate in joint destruction in both animal models of RA and human disease [6,7]. Receptor activator of nuclear factor κB ligand (RANKL) has been reported to be a potent regulator of osteoclast differentiation and activation [8-11]. Recent biological therapies against TNF-α and IL-1β have demonstrated promising effects protecting against progressive joint destruction [12-15]. The clinical use of these therapies has been limited, however, due to several issues, including safety and cost of treatment.Peroxisome proliferator-activated receptor (PPAR)γ is a member of the ligand-activated transcription factors in the nuclear receptor superfamily and was initially characterized as a key regulator of adipocyte differentiation and lipid metabolism [16,17]. Recent studies have demonstrated that PPARγ agonists prove to have anti-inflammatory and immunomodulatory therapeutic effects [2]. Indeed, the natural PPARγ ligand 15-deoxy-Delta (12,14)-prostaglandin J2 as well as synthetic PPARγ agonists such as rosiglitazone and troglitazone have been shown to ameliorate arthritis in rodent models [18,19]. However, the mechanisms for the beneficial effects of PPARγ agonists in arthritis have not been fully delineated. THR0921 is an orally active PPARγ agonist with potent anti-diabetic effects. Its main structural components consist of a thiazolidinedione (TZD) ring covalentl
AI Sport Forecast Software
Kiyomi Cerezo Takahash
International Journal of Interactive Multimedia and Artificial Intelligence , 2008,
Abstract: This article aims to explain the development of an application whose function is to predict the results of different sporting encounters. To do this an analysis of the influential factors, algorithms and technology implemented, will be carried out.
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