• Bulletin of the Korean Chemical Society
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• v.5 no.1
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• pp.16-21
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• 1984

The relative Arrhenius parameters for t-butoxy radical decomposition (log $A_d$, $E_d$) and hydrogen abstraction of t-butoxy radical from hydrogen donor (log $A_d$, $E_d$) by competitive method were obtained as follows: for cyclohexane; log $A_a/A_d$ = -4.17 mole/l and $E_d-E_a$ = 9.01 kcal/mole, for isobutane; log $A_a/A_d$ = -5.70 mole/l and $E_e-E_a$= 11.0 kcal/mole. From the reported Arrhenius parameters for t-Butoxy radical decomposition reactions the parameters for t-Butoxy radical reactions with isobutane and cyclohexane are estimated to be log $A(l/mol{\cdot}sec)$ = 8.4, $E_a$ = 4.3 kcal/mol and $log A (l/mol{\cdot}sec)= 9.9,\;E_a$ = 6.3 kcal/mol, respectively.

• Bulletin of the Korean Mathematical Society
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• v.56 no.5
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• pp.1297-1314
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• 2019

In this work, we investigate the following fractional boundary value problems $$\{_tD^{\alpha}_T({\mid}_0D^{\alpha}_t(u(t)){\mid}^{p-2}_0D^{\alpha}_tu(t))\\={\nabla}W(t,u(t))+{\lambda}g(t){\mid}u(t){\mid}^{q-2}u(t),\;t{\in}(0,T),\\u(0)=u(T)=0,$$ where ${\nabla}W(t,u)$ is the gradient of W(t, u) at u and $W{\in}C([0,T]{\times}{\mathbb{R}}^n,{\mathbb{R}})$ is homogeneous of degree r, ${\lambda}$ is a positive parameter, $g{\in}C([0,T])$, 1 < r < p < q and ${\frac{1}{p}}<{\alpha}<1$. Using the Fibering map and Nehari manifold, for some positive constant ${\lambda}_0$ such that $0<{\lambda}<{\lambda}_0$, we prove the existence of at least two non-trivial solutions

• Journal of Korean Biological Nursing Science
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• v.25 no.1
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• pp.73-85
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• 2023

Purpose: This study focused on identifying the interaction effects of genetic and lifestyle-environmental factors on the development of type 2 diabetes mellitus (T2D). Methods: Study subjects were selected from the Korean Genome and Epidemiology Study (KoGES) from 2001 to 2014. Data on genetic variations, anthropometric measurements, biochemical data, and seven lifestyle factors (diet, physical activity, alcohol drinking, smoking, sleep, depression, and stress) were obtained from 4,836 Koreans aged between 40 and 59 years, including those with T2D at baseline (n = 1,209), newly developed T2D (n= 1,298) and verified controls (n = 3,538). The genetic risk score (GRS) was calculated by using 11 single-nucleotide polymorphisms (SNPs) related to T2D development and the second quartile was used as the reference category. A Cox proportional hazards regression model was used to evaluate the associations of GRS and lifestyle factors with T2D risk, controlling for covariates. Results: Multivariate regression analysis revealed that GRS was the strongest risk factor for T2D, and body mass index (BMI), smoking, drinking, and spicy food preference also increased the risk. Lifestyle/environmental factors that showed significant interactions with GRS were BMI, current smoking, current drinking, fatty food preference, and spicy food preference. Conclusions: Interactions between genetic factors and lifestyle/environmental factors were associated with an increased risk of T2D. The results will be useful to provide a new perspective on genetic profiling for the earlier detection of T2D risk and clues for personalized interventions, which might be more effective prevention strategies or therapies in individuals with a genetic predisposition to T2D.

• Investigative Magnetic Resonance Imaging
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• v.20 no.2
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• pp.81-87
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• 2016

Purpose: To analyze the feasibility of three-dimensional (3D) diffusion-weighted (DW) PSIF (reversed FISP [fast imaging with steady-state free precession]) sequence in order to evaluate peripheral nerves in the elbow. Materials and Methods: Ten normal, asymptomatic volunteers were enrolled (6 men, 4 women, mean age 27.9 years). The following sequences of magnetic resonance images (MRI) of the elbow were obtained using a 3.0-T machine: 3D DW PSIF, 3D T2 SPACE (sampling perfection with application optimized contrasts using different flip angle evolution) with SPAIR (spectral adiabatic inversion recovery) and 2D T2 TSE (turbo spin echo) with modified Dixon (m-Dixon) sequence. Two observers used a 5-point grading system to analyze the image quality of the ulnar, median, and radial nerves. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of each nerve were measured. We compared 3D DW PSIF images with other sequences using the Wilcoxon-signed rank test and Friedman test. Inter-observer agreement was measured using intraclass correlation coefficient (ICC) analysis. Results: The mean 5-point scores of radial, median, and ulnar nerves in 3D DW PSIF (3.9/4.2/4.5, respectively) were higher than those in 3D T2 SPACE SPAIR (1.9/2.8/2.8) and 2D T2 TSE m-Dixon (1.7/2.8/2.9) sequences (P < 0.05). The mean SNR in 3D DW PSIF was lower than 3D T2 SPACE SPAIR, but there was no difference between 3D DW PSIF and 2D T2 TSE m-Dixon in all of the three nerves. The mean CNR in 3D DW PSIF was lower than 3D T2 SPACE SPAIR and 2D T2 TSE m-Dixon in the median and ulnar nerves, but no difference among the three sequences in the radial nerve. Conclusion: The three-dimensional DW PSIF sequence may be feasible to evaluate the peripheral nerves around the elbow in MR imaging. However, further optimization of the image quality (SNR, CNR) is required.

• Archives of Pharmacal Research
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• v.27 no.6
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• pp.640-645
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• 2004

Histone deacetylase inhibitors are new class of chemotherapeutic drugs able to induce tumor cell apoptosis and／or cell cycle arrest. Trichostatin A, an antifungal antibiotic, and HC-toxin are potent and specific inhibitors of histone deacetylase activity. In this study, we have examined the antiproliferative activities of trichostatin A and HC-toxin in estrogen receptor positive human breast cancer, T47D cells. Both trichostatin A and HC-toxin showed potent antiprolifer-ative efficacy and cell cycle arrest at $G_2/M$ in T47D human breast cancer cells in a dose-dependent manner. Trichostatin A caused potent apoptosis of T47D human breast cancer cells and trichostatin A-induced apoptosis might be involved in an increase of caspase-3／7 activity. HC-toxin evoked apoptosis of T47D cells and HC-toxin induced apoptosis might not be medi-ated through direct increase in caspase-3/7 activity. We have identified potent activities of anti-proliferation, apoptosis, and cell cycle arrest of trichostatin A and HC-toxin in estrogen receptor positive human breast cancer cell line T47D.

• Journal of the Chungcheong Mathematical Society
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• v.3 no.1
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• pp.41-48
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• 1990

Let D' : $C^n$[0, 1] ${\rightarrow}$ M be a second order derivation from the Banach algebra of n times continuously differentiable functions on [0, 1] into a Banach $C^n$[0, 1]-module M and let D be the primitive of D'. If D' is continuous and D'(z) lies in the 1-differential subspace, then it is completely determined by D(z) and D'(z) where z(t)=t, $0{\leq}t{\leq}1$.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.4
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• pp.339-348
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• 2020

We aimed to characterize the participation of rapid non-genomic and delayed non-genomic/genomic or genomic mechanisms in vasoactive effects to triiodothyronine (T3), emphasizing functional analysis of the involvement of these mechanisms in the genesis of nitric oxide (NO) of endothelial or muscular origin. Influences of in vitro and in vivo T3 treatments on contractile and relaxant responsiveness of isolated rat aortas were studied. In vivo T3-treatment was 500 ㎍·kg^-1·d^-1, subcutaneous injection, for 1 (T3_1d) and 3 (T3_3d) days. In experiments with endothelium-intact aortic rings contracted with phenylephrine, increasing concentrations of T3 did not alter contractility. Likewise, in vitro T3 did not modify relaxant responses induced by acetylcholine or sodium nitroprusside (SNP) nor contractile responses elicited by phenylephrine or angiotensin II in endothelium-intact aortas. Concentration-response curves (CRCs) to acetylcholine and SNP in endothelium-intact aortic rings from T3_1d and T3_3d rats were unmodified. T3_3d, but not T3_1d, treatment diminished CRCs to phenylephrine in endothelium-intact aortic rings. CRCs to phenylephrine remained significantly depressed in both endothelium-denuded and endothelium-intact, nitric oxide synthase inhibitor-treated, aortas of T3_3d rats. In endothelium-denuded aortas of T3_3d rats, CRCs to angiotensin II, and high K⁺ contractures, were decreased. Thus, in vitro T3 neither modified phenylephrine-induced active tonus nor CRCs to relaxant and contractile agonists in endothelium-intact aortas, discarding rapid non-genomic actions of this hormone in smooth muscle and endothelial cells. Otherwise, T3_3d-treatment inhibited aortic smooth muscle capacity to contract, but not to relax, in an endothelium- and NO-independent manner. This effect may be mediated by delayed non-genomic/genomic or genomic mechanisms.

• Journal of applied mathematics & informatics
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• v.34 no.3_4
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• pp.269-284
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• 2016

In this paper, we firstly use Krasnosel'skii fixed point theorem to investigate positive solutions for the following three-point boundary value problems for p-Laplacian with a parameter $({\phi}_P(D^{\alpha}_{0}+u(t)))^{\prime}+{\lambda}f(t, u(t))=0$, 0$D^{\alpha}_{0}+u(0)=u(0)=u{\prime}{\prime}(0)=0$, $u^{\prime}(1)={\gamma}u^{\prime}(\eta)$ where ϕ_p(s) = |s|^p−2s, p > 1, $D^{\alpha}_{0^+}$ is the Caputo's derivative, α ∈ (2, 3], η, γ ∈ (0, 1), λ > 0 is a parameter. Then we use Leggett-Williams fixed point theorem to study the existence of three positive solutions for the fractional boundary value problem $({\phi}_P(D^{\alpha}_{0}+u(t)))^{\prime}+f(t, u(t))=0$, 0$D^{\alpha}_{0}+u(0)=u(0)=u{\prime}{\prime}(0)=0$, $u^{\prime}(1)={\gamma}u^{\prime}(\eta)$ where ϕ_p(s) = |s|^p−2s, p > 1, $D^{\alpha}_{0^+}$ is the Caputo's derivative, α ∈ (2, 3], η, γ ∈ (0, 1).

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1250-1261
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• 2002

Many research works have validated the J-T approach to elastic-plastic crack-tip stress fields in a variety of plane strain specimens. To generalize the validity of J-T method, further investigations are however needed for more practical 3D structures than the idealized plane strain specimens. In this work, we perform 3D finite element (FE) modeling of welded plate and straight pipe, and accompanying elastic, elastic-plastic FE analyses. Manual 3D modeling is almost prohibitive, since the models contain semi-elliptical interfacial cracks which require singular elements. To overcome this kind of barrier, we develop a program generating the meshes for semi-elliptical interfacial cracks. We then compare the detailed 3D FE stress fields to those predicted with J-T two parameters. Thereby we extend the validity of J-T application to 3D structures and infer some useful informations for the design or assessment of pipe welds.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.136-141
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• 1988

Susceptibility of a thermophilic strain (D-71) of Saccharomyces cerevisiae and an osmotolerant strain (SR-S) of Zygosaccharomyces rouxii to Zymolyase-20T were studied in various renditions. Content of glucan and mannan in cell wall of Saocharomyces cerevisiae D-71 were 14.5% and 14.8%, and Zygosaccharomyces rouxii SR-S were 24.0% and 19.0%, respectively. Susceptibility of Saccharomyces cerevisiae D-71 cultured in Wickerham synthetic medium containing 0.5% of methionine and 0.1% of glucose to Zymolyase-20T was 66%, and $K_2$HPO$_4$ and aminobenzoic acid were greatly effective to susceptibility. Susceptibility of Zygosaccharomyces rouxii SR-S cultured in Wickerhnin synthetic medium containing 0.5% of peptone, 0.15% of methionine and 0.l% of glucose to Zymolyase-20T was 80%, and KI and pyridoxine were greatly effective to susceptibility. Susceptibility of Saccharomyces cerevisiae D-71 stationary cultured in YMPG medium at $25^{\circ}C$ for 12 hours was 16o1e and Zygosaccharomyces rouxii SR-S stationary cultured in YMPG medium at $25^{\circ}C$ for 30 hours was 82%.