• 대한수학회지
• /
• 제57권4호
• /
• pp.893-913
• /
• 2020

Let 𝓢 be the collection of the operator matrices $\(\array{A&C\\Z&B}\)$ where the range of C is closed. In this paper, we study the properties of operator matrices in the class 𝓢. We first explore various local spectral relations, that is, the property (β), decomposable, and the property (C) between the operator matrices in the class 𝓢 and their component operators. Moreover, we investigate Weyl and Browder type spectra of operator matrices in the class 𝓢, and as some applications, we provide the conditions for such operator matrices to satisfy a-Weyl's theorem and a-Browder's theorem, respectively.

• 대한임상검사과학회지
• /
• 제48권4호
• /
• pp.327-334
• /
• 2016

최근 사람과 가축에 항균제의 과도한 사용으로 감염병을 일으키는 병원성 세균들의 항균제 내성이 증가하고 있다. 본 연구에서는 PCR과 염기서열분석법을 이용하여 충청지역 일개의 대학병원에 의뢰된 임상검체와 같은 지역에서 사육된 닭으로부터 분리된 P. mirabilis 균주를 대상으로 16S ribosomal RNA methyltransferase(RMTase) 유전자와 integron을 조사하였다. 또한 Repetitive extragenic palindromic sequence-based PCR (REP-PCR)을 이용하여 P. mirabilis 균주들의 역학적 연관성 조사하였다. 총 38균주의 P. mirabilis 중에서 임상검체로부터 분리된 7균주 (18.4%)만이 RMTases 유전자를 가지고 있었는데 이들은 모두 amikacin, tobramycin, 및 gentamicin에 내성을 나타냈다. 또한 대상균주 중 23균주(60.5%)가 class 1 integron을 가지고 있는 것으로 나타났으며 class 2 및 class 3 integron은 검출되지 않았다. 본 연구에서 확인된 integrons에는 aminoglycoside 내성유전자(aadA2, aadA5, aadA7, 및 aacCA5), ${\beta}$-lactmam 내성유전자($bla_{PSE}$), erythromycin 내성유전자(ereA), lincosamides 내성유전자(linF), 및 trimethoprim 내성유전자(dfrA12, dfrA17 및 dfrA32)등이 유전자 카세트로 포함되어 있었다. 본 연구결과 RMTase 유전자는 임상검체로부터 분리된 P. mirabilis 균주에만 확산되어 있었던 반면 class 1 integrons는 임상검체와 닭으로부터 분리된 P. mirabilis 균주에 광범위하게 확산되어 있음을 확인할 수 있었다. 게다가 닭으로부터 분리된 균주 중에는 동일한 REP-PCR 밴드패턴을 보인 균주들이 있었는데 이는 닭들 사이에서 P. mirabilis 균주가 수평확산 되었음을 의미한다. P. mirabilis 균주에서 항균제 내성유전자의 확산을 막기 위해서는 내성유전자 지속적인 모니터링과 감시가 필요할 것으로 사료된다.

• 충청수학회지
• /
• 제25권4호
• /
• pp.655-668
• /
• 2012

An operator $T\;{\varepsilon}\;B(\mathcal{H})$ is said to be $k$-quasi-paranormal operator if $||T^{k+1}x||^2\;{\leq}\;||T^{k+2}x||\;||T^kx||$ for every $x\;{\epsilon}\;\mathcal{H}$, $k$ is a natural number. This class of operators contains the class of paranormal operators and the class of quasi - class A operators. In this paper, using the operator matrix representation of $k$-quasi-paranormal operators which is related to the paranormal operators, we show that every algebraically $k$-quasi-paranormal operator has Bishop's property ($\beta$), which is an extension of the result proved for paranormal operators in [32]. Also we prove that (i) generalized Weyl's theorem holds for $f(T)$ for every $f\;{\epsilon}\;H({\sigma}(T))$; (ii) generalized a - Browder's theorem holds for $f(S)$ for every $S\;{\prec}\;T$ and $f\;{\epsilon}\;H({\sigma}(S))$; (iii) the spectral mapping theorem holds for the B - Weyl spectrum of T.

• 대한수학회보
• /
• 제38권3호
• /
• pp.449-461
• /
• 2001

The purpose of this paper is to study several geometric properties for the new class $G_{\kappa}(\beta)$ including geometric interpretation, coefficient estimates, radius of convexity, distortion property and covering theorem.

• IMMUNE NETWORK
• /
• 제6권2호
• /
• pp.102-110
• /
• 2006

Background: Dendritic cells (DC) are professional antigen-presenting cells in the immune system and can induce T cell response against virus infections, microbial pathogens, and tumors. Therefore, immunization using DC loaded with tumor-associated antigens (TAAs) is a powerful method of inducing anti-tumor immunity. For induction of effective anti-tumor immunity, antigens should be efficiently introduced into DC and presented on MHC class I molecules at high levels to activate antigen-specific $CD8^+$ T cells. We have been exploring methods for loading exogenous antigens into APC with high efficiency of Ag presentation. In this study, we tested the effect of the cationic liposome (Lipofectin) for transferring and loading exogenous model antigen (OVA protein) into BM-DC. Methods: Bone marrow-derived DC (EM-DC) were incubated with OVA-Lipofectin complexes and then co-cultured with B3Z cells. B3Z activation, which is expressed as the amount of ${\beta}$-galactosidase induced by TCR stimulation, was determined by an enzymatic assay using ${\beta}$-gal assay system. C57BL/6 mice were immunized with OVA-pulsed DC to monitor the in vivo vaccination effect. After vaccination, mice were inoculated with EG7-OVA tumor cells. Results: BM-DC pulsed with OVA-Lipofectin complexes showed more efficient presentation of OVA-peptide on MHC class I molecules than soluble OVA-pulsed DC. OVA-Lipofectin complexes-pulsed DC pretreated with an inhibitor of MHC class I-mediated antigen presentation, brefeldin A, showed reduced ability in presenting OVA peptide on their surface MHC class I molecules. Finally, immunization of OVA-Lipofectin complexes-pulsed DC protected mice against subsequent tumor challenge. Conclusion: Our data provide evidence that antigen-loading into DC using Lipofectin can promote MHC class I- restricted antigen presentation. Therefore, antigen-loading into DC using Lipofectin can be one of several useful tools for achieving efficient induction of antigen-specific immunity in DC-based immunotherapy.

• Journal of applied mathematics & informatics
• /
• 제42권1호
• /
• pp.189-197
• /
• 2024

The purpose of this paper is to introduce and study the new class of spaces called the fuzzy 𝛽-Volterra spaces with the help of fuzzy β-dense and fuzzy 𝛽-G_𝛿 sets. Examples are given to illustrate the concept. Some interesting characterizations of the fuzzy 𝛽-Volterra spaces are established in this paper.

• Journal of the Korean Data and Information Science Society
• /
• 제15권4호
• /
• pp.783-791
• /
• 2004

In this paper we review recent developments in nonlinear time series modeling on both conditional mean and conditional variance. Traditional linear model in conditional mean is referred to as ARMA(autoregressive moving average) process investigated by Box and Jenkins(1976). Nonlinear mean models such as threshold, exponential and random coefficient models are reviewed and their characteristics are explained. In terms of conditional variances, ARCH(autoregressive conditional heteroscedasticity) class is considered as typical linear models. As nonlinear variants of ARCH, diverse nonlinear models appearing in recent literature including threshold ARCH, beta-ARCH and Box-Cox ARCH models are remarked. Also, a class of unified nonlinear models are considered and parameter estimation for that class is briefly discussed.

• 대한미생물학회지
• /
• 제35권5_6호
• /
• pp.337-339
• /
• 2000

MRSA, erythromycin-resistant S. pyogenes, penicillin non-susceptible pneumococci, PPNG, ESBL-producing E. coli and K. pneumoniae, class C ${\beta}$-lactamase-producing E. coli, fluoroquinolone-resistant E. coli, aminoglycoside-resistant A. baumannii and P. aeruginosa are all prevalent in Korea, which suggest the presence of high levels of antimicrobial selective pressure and nosocomial spread of resistant bacteria. Rapid increase of VRE and emergence of fluoroquinolone-resistant gonococci and VIM-2 metallo-${\beta}$-lactamase-producing P. aeruginosa are recently observed new threats in Korea.

• Kyungpook Mathematical Journal
• /
• 제53권3호
• /
• pp.467-478
• /
• 2013

The purpose of the present paper is to establish some interesting results involving coefficient conditions, extreme points, distortion bounds and covering theorems for the classes $V_H({\beta})$ and $U_H({\beta})$. Further, various inclusion relations are also obtained for these classes. We also discuss a class preserving integral operator and show that these classes are closed under convolution and convex combinations.

• 대한수학회보
• /
• 제56권5호
• /
• pp.1099-1115
• /
• 2019

In the present paper, we establish certain $L^p$ bounds for the generalized parametric Marcinkiewicz integral operators associated to surfaces generated by polynomial compound mappings with rough kernels in Grafakos-Stefanov class ${\mathcal{F}}_{\beta}(S^{n-1})$. Our main results improve and generalize a result given by Al-Qassem, Cheng and Pan in 2012. As applications, the corresponding results for the generalized parametric Marcinkiewicz integral operators related to the Littlewood-Paley $g^*_{\lambda}$-functions and area integrals are also presented.