Hyun-Chul Kim

Bio: Hyun-Chul Kim is an academic researcher from Inha University. The author has contributed to research in topics: Large Hadron Collider & Lepton. The author has an hindex of 176, co-authored 4076 publications receiving 183227 citations. Previous affiliations of Hyun-Chul Kim include Konkuk University & University of Edinburgh.

Magnetic moments of the SU(3) decuplet baryons in the chiral quark - soliton model

Abstract: Magnetic moments of baryons are studied within the chiral quark soliton model with special emphasis on the decuplet of baryons. The model is used to identify all symmetry breaking terms proportional to $m_{\rm s}$. Sum rules for the magnetic moments are derived. A ``model-independent'' analysis of the symmetry breaking terms is performed and finally model calculations are presented, which show the importance of the rotational $1/N_{\rm c}$ corrections for cranking of the soliton.

Plasma and urinary Vascular Endothelial Growth Factor and Diabetic Nephropathy in Type 2 Diabetes Mellitus

Abstract: Background: VEGF(vascular endothelial growth factor) has been implicated in the pathogenesis of neovascularization and endothelial dysfunction in diabetes mellitus. However, its precise role in diabetic nephropathy is still unknown. Our aims were to determine whether alterations of plasma and urinary VEGF levels were related to diabetic microvascular complications, especially nephropathy in type 2 diabetic patients. Methods: 107 type 2 diabetic patients, without non-diabetic kidney diseases, and 47 healthy control subjects were studied. The urinary albumin excretion was defined as the albumin-to-creatinine ratio(ACR) in 24 hour urine samples. The study subjects were divided into four groups: a nondiabetic healthy control group(n=47), a normoalbuminuric diabetic group(ACR /mg, n=37), a microalbuminuric diabetic group(ACR 30-299/mg, n=37) and an overt proteinuric diabetic group(ACR=300/mg, n=33). The plasma and urinary VEGF levels were measured in these subjects by enzyme-linked immunosorbent assays. Results: 1) The urinary VEGF concentrations were significantly higher in the diabetic groups than in the controls, even in the normoalbuminuric stage(log VEGF/Cr, normoalbuminuria; 4.331.06 vs. control; 3.530.79, p=0.009). The levels of urinary VEGF excretions increased with advancing diabetic nephropathy stage. 2) The plasma and urinary VEGF levels were higher in the hypertensive diabetic than the normotensive diabetic patients. 3) In the diabetic patients, the level of plasma VEGF was positively correlated with the BUN(r=0.398, p=0.039) and urinary ACR (r=0.251, p=0.044). The level of urinary VEGF was positively correlated with the urinary ACR(r=0.645, p

Expression of cyclooxygenase-2 protein in colorectal carcinomas.

Abstract: Background. Overexpression of cyclooxygenase-2 (COX-2) has been demonstrated in various human cancers, including colorectal cancer. Thus, overexpression of COX-2 may be involved in the growth and progression of cancer, and this may have prognostic significance. Aim. The aim of our study is to evaluate the expression of COX-2 in colorectal cancer tissue, and to examine the relationship of its expression to various clinicopathological parameters and patient survival. Methods. Formalin-fixed, paraffin-embedded tissue blocks were obtained from 60 patients who underwent surgery for colorectal carcinoma in 1995 at the Chonnam National University Hospital in Gwangju, Korea. We have used an immunohistochemical technique to localize COX-2 in colorectal carcinoma tissues. Results. Immunohistochemical staining of the colorectal cancer specimens demonstrated that COX-2 expression was localized to the carcinoma cells and was not detectable in the stromal compartment of the cancers. The COX-2 immunostaining pattern was predominantly homogenous, and perinuclear cytoplasmic within the tumors. Normal colonic epithelium adjacent to the tumor showed no staining for COX-2. The COX-2 protein was detected in 70% (42/60) of colorectal carcinoma tissues. However, no significant correlation was found between COX-2 expression and various clinicopathological parameters, including histologic grade, tumor size, depth of invasion, lymph node metastasis, distant metastasis, or stage. Furthermore, COX-2 expression did not correlate with patient survival (p=0.401). Conclusion. These results suggest that COX-2 expression may play an important role in the evolution of colon carcinogenesis. However, further studies are needed to determine the prognostic relevance of COX-2.

Search for heavy Majorana neutrinos in e±e±+ jets and e±µ±+ jets events in proton-proton collisions at √s = 8 TeV

Abstract: A search is performed for heavy Majorana neutrinos (N) decaying into a W boson and a lepton using the CMS detector at the Large Hadron Collider. A signature of two jets and either two same sign electrons or a same sign electron-muon pair is searched for using 19.7 inverse-femtobarns of data collected during 2012 in proton-proton collisions at a centre-of-mass energy of 8 TeV. The data are found to be consistent with the expected standard model (SM) background and, in the context of a Type-1 seesaw mechanism, upper limits are set on the cross section times branching fraction for production of heavy Majorana neutrinos in the mass range between 40 and 500 GeV. The results are additionally interpreted as limits on the mixing between the heavy Majorana neutrinos and the SM neutrinos. In the mass range considered, the upper limits range between 0.00015 - 0.72 for |V[eN]|^2 and 6.6E-5 - 0.47 for |V[eN]V*[muN]|^2 / ( |V[eN]|^2 + |V[muN]|^2 ), where V[lN] is the mixing element describing the mixing of the heavy neutrino with the SM neutrino of flavour l. These limits are the most restrictive direct limits for heavy Majorana neutrino masses above 200 GeV.

Search for the Production of Narrow t(b)over-bar Resonances in 1:9 fb(-1) of p(p)over-bar Collisions at root s=1.96 TeV

Abstract: We present new limits on resonant tb production in ppbar collisions at sqrt(s) = 1.96 TeV, using 1.9 fb{sup -1} of data recorded with the CDF II detector at the Fermilab Tevatron. We reconstruct a putative tb mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous tb production as modeled by W{prime} {yields} tb. We set a new limit on a right-handed W{prime} with standard model-like coupling, excluding any mass below 800 GeV at 95% C.L. For any narrow W{prime}-like state with mass above 800 GeV, the cross-section is found to be less than 0.28 pb at 95% C.L. We also present an exclusion of the W{prime} coupling strength versus W{prime} mass.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。