• Communications for Statistical Applications and Methods
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• v.25 no.1
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• pp.29-42
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• 2018

We combine the integer-valued GARCH(1, 1) model with a generalized regime-switching model to propose a dynamic count time series model. Our model adopts Markov-chains with time-varying dependent transition probabilities to model dynamic count time series called the generalized regime-switching integer-valued GARCH(1, 1) (GRS-INGARCH(1, 1)) models. We derive a recursive formula of the conditional probability of the regime in the Markov-chain given the past information, in terms of transition probabilities of the Markov-chain and the Poisson parameters of the INGARCH(1, 1) process. In addition, we also study the forecasting of the Poisson parameter as well as the cumulative impulse response function of the model, which is a measure for the persistence of volatility. A Monte-Carlo simulation is conducted to see the performances of volatility forecasting and behaviors of cumulative impulse response coefficients as well as conditional maximum likelihood estimation; consequently, a real data application is given.

• Nonlinear Functional Analysis and Applications
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• v.29 no.2
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• pp.597-620
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• 2024

In this study, the conformable fractional derivative(CFD) of order 𝝔 in conjunction with the LC operator of orderρ is used to develop the model of the transmission of the A(H1N1) influenza infection. A brand-new A(H1N1) influenza infection model is presented, with a population split into four different compartments. Fixed point theorems were used to prove the existence of the solutions and uniqueness of this model. The basic reproduction number R₀ was determined. The least and most sensitive variables that could alter R₀ were then determined using normalized forward sensitivity indices. Through numerical simulations carried out with the aid of the Adams-Moulton approach, the study also investigated the effects of numerous biological characteristics on the system. The findings demonstrated that if 𝝔 < 1 and ρ < 1 under the CFD, also the findings demonstrated that if 𝝔 = 1 and ρ = 1 under the CFD, the A(H1N1) influenza infection will not vanish.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.169-174
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• 2002

Resveratrol is known to have potent cancer chemopreventive activity against tumorigenesis caused by 7,12-dimetylbenz［$\alpha$］anthracene(DMBA) which is known to be oxidized to reactive products by cytochrome P450 1B1 (CYP1B1). The effects of resveratrol on the activity of recombinant human P450 1 family enzymes, expressed in Escherichia coli membranes with human NADPH-P450 reductase, were determined by measuring alkoxyresorufin O-dealkylation activity, e.g., ethoxyresorufin O-deethylation (EROD) CYP1A1, methoxyresorufin O-demethylation (MROD), CYP1A2, benzyloxyresorufin-O-debenzylation (BROD), CTP1B1. Resveratrol inhibited CYP1B1 and CYP1A1 activities in a dose-dependent manner with $IC_{50}$/ values of 59 and 10$\mu$M for EROD activity and 1.8 and 30$\mu$M for BROD activity, respectively. Resveratrol had only weak inhibitory effect on CYP1A2 activity ($IC_{50}$/ values of 0.44 mM for EROD and ＞2 mM for MROD). Furthermore, resveratrol did not affect NADPH-P450 reductase activity significantly. Resveratrol inhibited the CYP1B1-dependent EROD activity with a $K_{i}$ of 28 $\mu$M in a non-competitive type manner. these results suggest that resveratrol-derived inhibited of CYP1B1 and CYP1A1 activities may contribute to the suppression of DMBA inducible tumorigenesis observed in extrahepatic tissues.s.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3691-3698
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• 2014

Background: Published studies on the association between the Ras Association Domain Family 1 isoform A (RASSF1A) Ala133Ser polymorphism and cancer susceptibility have yielded conflicting results. Thus, a meta-analysis was here performed to assess the possible association. Materials and Methods: All eligible case-control studies published up to November 2013 on the association between RASSF1A Ala133Ser polymorphism and cancer susceptibility were identified by searching PubMed, Web of Science, Science Direct and hand search. Bothfixed-effect and random-effect models were used to calculate pooled odds ratios (ORs) with 95% confidence intervals (CIs) by using the Comprehensive Meta-Analysis software version 2.2. Results: A total of 10 studies including 4,572 cancer cases and 4,320 controls were included in the meta-analysis. Overall, significantly increased cancer risk was associated with the variant Ser133 when all studies were pooled (Ser vs Ala: OR=1.51, 95% CI=1.08-2.12, $P_{heterogeneity}{\leq}0.001$; Ser/Ser+Ala/Ser vs Ala/Ala: OR=1.55, 95% CI=1.08-2.22, $P_{heterogeneity}{\leq}0.001$). Moreover, in subgroup analyses by cancer types, a significant association between RASSF1A Ala133Ser polymorphism and lung cancer risk was found (Ser vs Ala: OR=2.27, 95% CI=1.29-4.02, $P_{heterogeneity}$=0.61; Ser/Ser+Ala/Ser vs Ala/Ala: OR=2.42, 95% CI=1.33-4.42, $P_{heterogeneity}=0.75$). In addition, in subgroup analyses by ethnicity, it was found that the RASSF1A Ala133Ser polymorphism was associated with overall cancer risk in Asians (Ser vs Ala: OR=1.37, 95% CI=1.06-1.77, $P_{heterogeneity}=0.06$) and Caucasians (Ser/Ser+Ala/Ser vs Ala/Ala: OR=2.21, 95% CI=1.01-4.82, $P_{heterogeneity}{\leq}0.001$). Conclusions: This meta-analysis suggests, for the first time, that RASSF1A Ala133Ser polymorphism may contribute to cancer susceptibility, especially for lung cancer. Besides, additional well-designed studies with larger sample size focusing on different ethnicities and cancer types are needed to confirm these findings.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2013-2020
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• 2014

Background: The aldehyde dehydrogenase 1 family member A1 (ALDH1A1) is one of the promising markers for identifying cancer stem cells in many cancer types, along with other markers including CD44. The aim of the present study was to evaluate the expression and clinical significance of putative cancer stem cell markers, CD44 and ALDH1A1, in a series of urothelial carcinomas of urinary bladder (UCUB) by tissue microarray (TMA). Materials and Methods: A total of 159 Urothelial Carcinomas (UC) including 96 (60%) low grade and 63 (40%) high grade carcinomas were immunohistochemically examined for the expression of CD44 and ALDH1A1. Correlations of the relative expression of these markers with clinicopathological parameters were also assessed. Results: High level expression of ALDH1A1 was found in 16% (25/159) of bladder UC which was significantly correlated with increased tumor size (p value=0.002), high grade (p value<0.001), pathologic stage (T1, p value=0.007 and T2, p value<0.001) and increased rate of recurrence (p value=0.013). A high level of CD44 expression was found in 43% (68/159) of cases, being positively correlated with histologic grade (p value=0.032) and recurrence (p value=0.039). Conclusions: Taken together, our results showed that ALDH1 was concurrently expressed in a fraction of CD44+ tumors and its expression correlated with poor prognosis in UCs. ALDH1A1 could be an ideal marker for targeted therapy of UCs in combination with conventional therapies, particularly in patients with high grade carcinomas. These findings indicate that cells expressing ALDH1A1 along with CD44 can be a potential therapeutic target in bladder carcinomas.

• Environmental Mutagens and Carcinogens
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• v.24 no.3
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• pp.143-150
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• 2004

In mammalian, cytochrome P4501A1 (CYP1A1) is very important for metabolism of xenobiotics such as PAHs(Polycyclic aromatic hydrocarbon) and heterocyclic amine, and it is induced by environmental contaminants such as PAHs, TCDD(2,3,7,8-tetrchlorodibenzo-p-dioxin) and 3-MC (3-methylcholanthrene). In fish, like mammalian, when it is exposed to environmental contaminants, they cause specific and sensitive induction of CYP1A. Therefore, induction of CYP1A in fish and mammalian is widely used as a biomarker for exposure of environmental contaminants. In this study, to compare the function of Cyp1a1 in fish with it in mammalian, we have used rainbow trout(Oncorhynchys mykiss) hepatoma cells (RTH-149) and mouse hepatocyte (Hepa-I). in order to examine induction of Cyp1a1 by TCDD, we have used the bioassay system. We examined effects of TCDD on the Cyp1a1-luciferase reporter gene activity, 7-ethoxyresorufin O-deethylase(EROD) activity and Cypa mRNA level.

• Journal of the Korean Mathematical Society
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• v.53 no.3
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• pp.549-582
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• 2016

All rings are commutative with $1{\neq}0$ and n is a positive integer. Let ${\phi}:{\Im}(R){\rightarrow}{\Im}(R){\cup}\{{\emptyset}\}$ be a function where ${\Im}(R)$ denotes the set of all ideals of R. We say that a proper ideal I of R is ${\phi}$-n-absorbing primary if whenever $a_1,a_2,{\cdots},a_{n+1}{\in}R$ and $a_1,a_2,{\cdots},a_{n+1}{\in}I{\backslash}{\phi}(I)$, either $a_1,a_2,{\cdots},a_n{\in}I$ or the product of $a_{n+1}$ with (n-1) of $a_1,{\cdots},a_n$ is in $\sqrt{I}$. The aim of this paper is to investigate the concept of ${\phi}$-n-absorbing primary ideals.

• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.582-585
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• 1989

Two crystal structures of dehydrated $Sr^{2+}\;and\;Tl^+$ exchanged zeolite A, $Sr_xTl_{12-2x}-A$ (x = 1.6 and 5.45), have been determined by single-crystal X-ray diffraction techniques. Their structures were solved and refined in the cubic space group Pm3m at $21(1)^{\circ}C.$ Both crystals were ion exchanged in flowing streams of mixed $Sr(NO_3)_2\;and\;TlNO_3$ aqueous solution, followed by dehydration at $360^{\circ}C\; and\; 2${\times}$10^{-6}$ Torr for 2 days. Full-matrix least-squares refinements of the dehydrated $Sr_{1.6}Tl_{8.8}-A (a = 12.214(2){\AA})\; and\;Sr_{5.45}Tl{1.1}-A (a=12.291(2){\AA})$ have converged to final error indices, $R_1=0.055\; and\;R_2=0.061$ with 286 reflections, and R1 = 0.072 and R2 = 0.090 with 217 reflections, respectively, for which$\;I\;{>}\;3{\sigma}(I)$. In both structures, all Sr(II) ions are coordinated by three framework oxygens; Sr(II) to O(3) distances are $2.21(2){\AA}\;for\;Sr_{1.6}Tl_{8.8}-A \;and\;2.31(1){\AA} \;for\;Sr_{5.45}Tl_{1.1}-A,$and Tl(I) to O(3) distances are $2.657(6){\AA}\;for\;Sr_{1.6}Tl_{8.8}-A\;and\;2.845(8){\AA}\;for\;Sr_{5.45}Tl_{1.1}-A,$ respectively. In each structure, the angle subtended at Sr(II), O(3)-Sr(II)-O(3) is $118.7(4)^{\circ}\;for\; Sr_{1.6}Tl_{8.8}-A \;and\;120.0(4)^{\circ}\;for\;Sr_{5.45}Tl_{1.1}-A.\;Sr^{2+}$ ions prefer to 6-ring sites and $Tl^+$ ions to 8-ring sites when total number of ions per unit cell is more than 8.

• Korean Journal of Crystallography
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• v.5 no.1
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• pp.1-6
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• 1994

Two possible space groups of the comfound, VP6N3018C24H:60, are: P 1, a=14.022(1), b=12.644(2), c= 12.640(1)A, a=8038(1), B=102.12(1), r=102.16(1), V=2124.1A3, Z=2, μ=0.47cm-1, d=1.46g/cm3, R=0.083 for 3350 independent reflections with Fo>4o IFI, and C2/c, a=19.32(2), b=16.32(2), c=14.02(1)A, B=105.98(5), β=105.98(5), V=4248.2A3, Z=4 R=0.083 for 1590 independent reflections with Fo>4c IFoI . In the space group P T, there are two monlecules in a unit cell. Vanadium atoms in the two monlecules occupy the two different special positions such that the complete monlecules are accomplished by the two independent center of symmetry. Therefore two different half molecules of bis(trimetaphosphate)vanadate and three molecules of tetraethylammonium are the asymmetric unit in a unit cell. In the space group C2/c, however, the vanadium atom is located at a special position with centrosymmetry, and a two-fold symmetry axis passes through C2/c, N2 and C25 atoms. Therefore the asymmrtic unit in a unit cell consists of a half molecule of bis(trimetaphosphate)vanadate and one and a half molecules of tetraethylammonium. All the molecular conformations in both space groups are very similar: six oxygen atoms coordinated to a vanadium atom in the bi s(trimetaphosphate)vanadate molecule form an octahedron and the four carbon atoms bonded to a nitrogen atom in the tetraethylammonium molecule are disordered so that the eight carbon atoms around nitrogen atom exhibit an irregular dodecahedral form.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.157-164
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• 2011

It is very difficult problem to factorize composite number. Integer factorization algorithms, for the most part, find ($a,b$) that is congruence of squares ($a^2{\equiv}b^2$(mode $n$)) with using factoring(factor base, B) and get the result, $p=GCD(a-b,n)$, $q=GCD(a+b,n)$ with taking the greatest common divisor of Euclid based on the formula $a^2-b^2=(a-b)(a+b)$. The efficiency of these algorithms hangs on finding ($a,b$). Fermat's algorithm that is base of congruence of squares finds $a^2-b^2=n$. This paper proposes the method to find $a^2-b^2=kn$, ($k=1,2,{\cdots}$). It is supposed $b_1$=0 or 5 to be surely, and b is a double number. First, the proposed method decides $k$ by getting kn that satisfies $b_1=0$ and $b_1=5$ about $n_2n_1$. Second, it decides $a_2a_1$ that satisfies $a^2-b^2=kn$. Third, it figures out ($a,b$) from $a^2-b^2=kn$ about $a_2a_1$ as deciding $\sqrt{kn}$ < $a$ < $\sqrt{(k+1)n}$ that is in $kn$ < $a^2$ < $(k+1)n$. The proposed algorithm is much more effective in comparison with the conventional Fermat algorithm.