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Search Results: 1 - 10 of 3590 matches for " Hyun Cheong "
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A case of native valve endocarditis caused by Burkholderia cepacia without predisposing factors
Hyun Ki, Sung Kim, Seong Han, Hae Cheong
BMC Infectious Diseases , 2011, DOI: 10.1186/1471-2334-11-114
Abstract: Here, we report the case of a patient who developed Burkholderia cepacia-induced native valve endocarditis with consequent cerebral involvement without any predisposing factors; she was successfully treated by antimicrobial agents only.In this report, we also present literature review of relevant cases.Burkholderia cepacia is a gram-negative bacillus. It is important nosocomial pathogen that particularly infects patients with cystic fibrosis [1] and chronic granulomatous diseases[2] and is known to be resistant to many anti-bacterial agents.Burkholderia cepacia rarely causes endocarditis in community settings, but it is known to cause infective endocarditis particularly in intravenous heroin users, and in patients with prosthetic valve replacement [3]. However, infective endocarditis caused by Burkholderia cepacia in patients without predisposing factors is rare [4-6].The treatment of Burkholderia cepacia endocarditis could be conservative, i.e., administration of antibacterial agents, and/or surgical modality [4-13]. According to the previous reports, most patients were prescribed trimethoprim-sulfamethoxazole and underwent valve surgery. Notwithstanding, the mortality in cases of infective endocarditis patients is not low despite the aggressive treatment of infective endocarditis [3].Here, we report the case of a patient with Burkholderia cepacia endocarditis and cerebral involvement who had no predisposing factors, and the infection was successfully managed only by antimicrobial treatment. Along with this case, we also present a literature review.A 77-year-old woman was transferred to our hospital from a local hospital for loss of consciousness and disorientation. She had experienced a fall 2 weeks before admission to our hospital. Plain spine radiography had revealed a spine compression fracture. Two days earlier, she was admitted to a local hospital for relief from back pain. However, during her stay at the hospital, she developed low grade fever, aphasia, and
Noncommutative homological mirror functor
Cheol-Hyun Cho,Hansol Hong,Siu-Cheong Lau
Mathematics , 2015,
Abstract: We formulate a constructive theory of noncommutative Landau-Ginzburg models mirror to symplectic manifolds based on Lagrangian Floer theory. The construction comes with a natural functor from the Fukaya category to the category of matrix factorizations of the constructed Landau-Ginzburg model. As applications, it is applied to elliptic orbifolds, punctured Riemann surfaces and certain non-compact Calabi-Yau threefolds to construct their mirrors and functors. In particular it recovers and strengthens several interesting results of Etingof-Ginzburg, Bocklandt and Smith, and gives a unified understanding of their results in terms of mirror symmetry and symplectic geometry. As an interesting application, we construct an explicit global deformation quantization of an affine del Pezzo surface as a noncommutative mirror to an elliptic orbifold.
Localized mirror functor for Lagrangian immersions, and homological mirror symmetry for P^1_{a,b,c}
Cheol-Hyun Cho,Hansol Hong,Siu-Cheong Lau
Mathematics , 2013,
Abstract: This paper gives a new way of constructing Landau-Ginzburg mirrors using deformation theory of Lagrangian immersions motivated by the works of Seidel, Strominger-Yau-Zaslow and Fukaya-Oh-Ohta-Ono. Moreover we construct a canonical functor from the Fukaya category to the mirror category of matrix factorizations. This functor derives homological mirror symmetry under some explicit assumptions. As an application, the construction is applied to spheres with three orbifold points to produce their quantum-corrected mirrors and derive homological mirror symmetry. Furthermore we discover an enumerative meaning of the (inverse) mirror map for elliptic curve quotients.
Localized mirror functor constructed from a Lagrangian torus
Cheol-Hyun Cho,Hansol Hong,Siu-Cheong Lau
Mathematics , 2014,
Abstract: Fixing a weakly unobstructed Lagrangian torus in a symplectic manifold $X$, we define a holomorphic function $W$ called the localized Floer potential. We construct a canonical $A_\infty$-functor from the Fukaya category of $X$ to the category of matrix factorizations of $W$. It provides a way to interpret a Lagrangian Floer complex as a matrix factorization directly. The technique is applied to toric Fano manifolds to transform Lagrangian branes to matrix factorizations. As a consequence, we obtain explicit generators of the category of matrix factorizations of a Laurent polynomial. We also compute the matrix factorization mirror to the real locus of the complex projective space explicitly.
AA mismatched DNAs with a single base difference exhibit a large structural change and a propensity for the parallel-stranded conformation
Chulhyun Lee,Hae-Kap Cheong,Jee-Hyun Cho,Chaejoon Cheong
Journal of Analytical Science & Technology , 2010,
Abstract: AA mismatches in DNA with different nearest-neighbor sequences were studied to understand the structural changes that accompany base-pair mismatches and the associated thermodynamics. Two synthesized duplexes, , 5' -d(CGACAATTGACG) (called AA1) and 5' -d(CGAGAATTCACG) (called AA2) as a palindrome sequences, had different nearest-neighbor sequences to the AA mismatches. This study focused on elucidating the structural and thermodynamic differences between these two molecules. A hydrogen bond between the mismatched adenines in AA1 was found, while no hydrogen bond in AA2. Both of the mismatched adenines in AA1 were stacked in the helix, while the mismatched adenine in AA2 surrounded by guanines was partially out of the helix and the other mismatched adenine surrounded by cytosines was stacked in the helix. Thermodynamically, AA1 was more stable than AA2. The melting temperature of the internal bases of AA1 was about 7 degree higher than that of AA2. The standard Gibbs free energy change for the duplex formation of AA1 was 1.30 Kcal/mol smaller than that of AA2. These thermal properties could be ascribed to the formation of the hydrogen bond. The conformational changes of these molecules at low pH were also investigated and compared. AA1 unambiguously assumed a parallel-stranded duplex at pH 4, while AA2 existed as a mixture of anti-parallel and parallel duplexes below pH 5.
Lagrangian Floer potential of orbifold spheres
Cheol-Hyun Cho,Hansol Hong,Sang-hyun Kim,Siu-Cheong Lau
Mathematics , 2014,
Abstract: For each sphere with three orbifold points, we construct an algorithm to compute the open Gromov-Witten potential, which serves as the quantum-corrected Landau-Ginzburg mirror and is an infinite series in general. This gives the first class of general-type geometries whose full potentials can be computed. As a consequence we obtain an enumerative meaning of mirror maps for elliptic curve quotients. Furthermore, we prove that the open Gromov-Witten potential is convergent, even in the general-type cases, and has an isolated singularity at the origin, which is an important ingredient of proving homological mirror symmetry.
A single nucleotide polymorphism in CAPN1 associated with marbling score in Korean cattle
Hyun Cheong, Du-Hak Yoon, Byung Park, Lyoung Kim, Joon Bae, Sohg Namgoong, Hae Lee, Chang Han, Ji Kim, Il-Cheong Cheong, Hyoung Shin
BMC Genetics , 2008, DOI: 10.1186/1471-2156-9-33
Abstract: By direct DNA sequencing in 24 unrelated Korean cattle, we identified 39 sequence variants within exons and their flanking regions in CAPN1. Among them, 12 common polymorphic sites were selected for genotyping in the beef cattle (n = 421). Statistical analysis revealed that a polymorphism in the 3'UTR (c.2151*479C>T) showed significant association with MS (Pcor. = 0.02).Our findings suggest that polymorphisms in CAPN1 might be one of the important genetic factors involved in carcass quality in beef cattle, although it could be false positive association.Genetic improvement has long been considered an important factor in the competitiveness of beef cattle production. Identification of the genes and/or polymorphisms underlying quantitative/qualitative traits, and an understanding of how these genes/polymorphisms interact with the environment or with other genes affecting economic traits might be the keys to successful application of marker-assisted selection in the commercial animal population. As one of these economic traits, marbling is intramuscular fat that gives meat flavor and tenderness. Thus, an increase in the degree of marbling raises the level of meat quality.Calpain is a ubiquitous cytoplasmic cysteine protease, the activity of which is absolutely dependent on calcium [1]. Two genes of calpain (CAPN1 [macro-calpain] and CAPN2 [mili-calpain]) have been identified [2]. CAPN1 degrades myofibrillar proteins under postmortem conditions and appears to be the primary enzyme in the postmortem tenderization process [3-6]. Regulation of CAPN1 activity has been correlated with variation in meat tenderness, and previous studies also identified a quantitative trait locus influencing meat tenderness on chromosome 29 where CAPN1 lies [7-9].In the CAPN1 gene, more than 100 single nucleotide polymorphisms (SNPs) have been identified in Bos indicus or Bos taurus [8,10,11] (S. N. White and T. Smith, unpublished data). Among them, four polymorphisms, two non-synonymous SNPs (
Preparation of Fe3O4-Embedded Poly(styrene)/Poly(thiophene) Core/Shell Nanoparticles and Their Hydrogel Patterns for Sensor Applications
Yong Seok Kim,Hyun Jong Lee,Patakamuri Govindaiah,Woohyun Son,Won-Gun Koh,In Woo Cheong,Jung Hyun Kim
Materials , 2014, DOI: 10.3390/ma7010195
Abstract: This research describes the preparation and sensor applications of multifunctional monodisperse, Fe 3O 4 nanoparticles-embedded poly(styrene)/poly(thiophene) (Fe 3O 4-PSt/PTh), core/shell nanoparticles. Monodisperse Fe 3O 4-PSt/PTh nanoparticles were prepared by free-radical combination (mini-emulsion/emulsion) polymerization for Fe 3O 4-PSt core and oxidative seeded emulsion polymerization for PTh shell in the presence of FeCl 3/H 2O 2 as a redox catalyst, respectively. For applicability of Fe 3O 4-PSt/PTh as sensors, Fe 3O 4-PSt/PTh-immobilized poly(ethylene glycol) (PEG)-based hydrogels were fabricated by photolithography. The hydrogel patterns showed a good sensing performance under different H 2O 2 concentrations. They also showed a quenching sensitivity of 1 μg/mL for the Pd 2+ metal ion within 1 min. The hydrogel micropatterns not only provide a fast water uptake property but also suggest the feasibility of both H 2O 2 and Pd 2+ detection.
Skeletochronological Age Determination and Comparative Demographic Analysis of Two Populations of the Gold-spotted Pond Frog (Rana chosenica)
Cheong, Seokwan,Daesik Park,Ha-Cheol Sung,Jung Hyun Lee
Journal of Ecology and Field Biology , 2007,
Abstract: To obtain demographic information on threatened gold-spotted pond frog (Rana chosenica Okada,1931) populations, we determined the ages of 45 male and 13 female frogs (20 males and 9 females fromCheongwon and 25 males and 4 females from Tae-an) and compared the age structures and growth patternsof the two populations in 2006. The snout-vent length (SVL) and body weight of female frogs were greater thanthose of male frogs in both populations. Male frogs’ ages ranged 2 to 7 years old and females’ ages ranged3 to 6 years old. In both populations, 4 years old male frogs were the most abundant age-sex class. The agestructures of the two populations were significantly different and the growth coefficients of male frogs from theCheongwon population were greater than those from the Tae-an population. The mean age of males from theTae-an population was higher than that from the Cheongwon population. However, the SVL and body weightsof male frogs were not different between two populations and there was no difference between the twopopulations in the mean male SVL at any age. The results could increase our understanding of the life-historyof this threatened frog and may be useful in conservation planning.
Lagrangian Floer superpotentials and crepant resolutions for toric orbifolds
Kwokwai Chan,Cheol-Hyun Cho,Siu-Cheong Lau,Hsian-Hua Tseng
Mathematics , 2012, DOI: 10.1007/s00220-014-1948-6
Abstract: We investigate the relationship between the Lagrangian Floer superpotentials for a toric orbifold and its toric crepant resolutions. More specifically, we study an open string version of the crepant resolution conjecture (CRC) which states that the Lagrangian Floer superpotential of a Gorenstein toric orbifold $\mathcal{X}$ and that of its toric crepant resolution $Y$ coincide after analytic continuation of quantum parameters and a change of variables. Relating this conjecture with the closed CRC, we find that the change of variable formula which appears in closed CRC can be explained by relations between open (orbifold) Gromov-Witten invariants. We also discover a geometric explanation (in terms of virtual counting of stable orbi-discs) for the specialization of quantum parameters to roots of unity which appears in Y. Ruan's original CRC ["The cohomology ring of crepant resolutions of orbifolds", Gromov-Witten theory of spin curves and orbifolds, 117-126, Contemp. Math., 403, Amer. Math. Soc., Providence, RI, 2006]. We prove the open CRC for the weighted projective spaces $\mathcal{X}=\mathbb{P}(1,\ldots,1,n)$ using an equality between open and closed orbifold Gromov-Witten invariants. Along the way, we also prove an open mirror theorem for these toric orbifolds.
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