Jun-Heon Lee

Nomenclature for factors of the SLA system, update 2008

This report summarizes the new swine leukocyte antigen (SLA) allele sequences and haplotypes designated by the SLA Nomenclature Committee of the International Society for Animal Genetics. There have been 74 new SLA alleles, comprising 18 SLA-1 alleles, 11 SLA-2 alleles, six SLA-3 alleles, two SLA-6 alleles, one SLA-DRA allele, 20 SLA-DRB1 alleles, three SLA-DQA alleles and 13 SLA-DQB1 alleles. Twelve new SLA class I and four new class II haplotypes have also been designated. This is the first official update since the 2005 reports on the nomenclature for factors of the SLA class I and II systems. This report also summarizes recent updates to the Immunopolymorphism Database-Major Histocompatibility Complex (IPD-MHC) website (http://www.ebi.ac.uk/ipd/mhc/sla/). All information has now been integrated to the SLA section of the IPD-MHC database, which serves as the repository for maintaining a list of all recognized SLA genes and their allelic sequences.

Molecular characterization of swine leucocyte antigen class I genes in outbred pig populations

The highly polymorphic swine leucocyte antigen (SLA) genes are one of the most important determinants in swine immune responses to infectious diseases, vaccines, and in transplantation success. Study of SLA influence requires accurate and effective typing methods. We developed a simple and rapid method to type alleles at the three classical SLA class I loci (SLA-1, SLA-3 and SLA-2) using the PCR-sequence-specific primer (PCR-SSP) strategy. This typing system relies on 47 discriminatory PCR primer pairs designed to amplify the SLA class I alleles by groups that have similar sequence motifs. We applied this low-resolution group-specific typing method to characterize the SLA class I alleles present in three outbred pig populations (n = 202). Alleles from 24 class I allele groups corresponding to 56 class I genotypes were detected. We also identified 23 low-resolution SLA class I haplotypes in these pigs and found haplotypes Lr-1.0 (SLA-1*01XX-SLA-3*01XX-SLA-2*01XX) and Lr-4.0 (SLA-1*04XX-SLA-3*04XX-SLA-2*04XX) in all three pig populations with a high prevalence. Over 80% of the pigs examined (n = 162) were found to bear at least one of these haplotypes, resulting in a combined haplotype frequency of nearly 50%. This PCR-SSP-based typing system demonstrates a reliable and unambiguous detection of SLA class I alleles, and can be used to effectively investigate the SLA diversity in outbred pig populations. It will help to identify the role of SLA antigens in disease-resistant pigs and may facilitate the development of effective vaccines.

MC carbide formation in directionally solidified MAR-M247 LC superalloy

Abstract MC-type carbide formation in MAR-M247 LC superalloy was systematically investigated using directional solidification and quenching methods in sample growth rates between 0.8×10−6 and 15×10−6 m s−1. The results indicate that carbide growth rate, carbide forming element enrichment and surrounding solid geometry determine carbide morphology and carbide composition. The carbide forming element enrichment and interface energy control carbide nucleation. Heterogeneous carbide nucleation can occur above the alloy liquidus temperature. Carbide forming element enrichment and trapping behavior of the solid–liquid interface control carbide growth, which occurs at inter-secondary γ-dendrite arm positions and the mushy zone bottom which are rich in carbide forming elements. At fast sample growth rates, the solid–liquid interface can trap carbide nuclei in front of it. This trapping tends to occur at the inter-secondary γ-dendrite arm region.

Preparation of tungsten powder by the combustion of CaWC4/Mg

Tungsten powder was prepared by a Self-Propagating High-Temperature Synthesis(SHS) Process of a CaWO4-Mg mixture. Mg vapor was discovered to significantly affect such combustion parameters as the combustion temperature(Tc), the combustion velocity(U), the relative mass change(δm) and the relative elongation(δh) of the sample. These effects could be reduced by decreasing the internal Ar pressure, sample density and reducing agent content. The oxygen content in tungsten was decreased by using 5% excess Mg; the carbon content was diminished when the combustion process occurred under PAr=0.1 MPa. The MgO and CaO in the product was leached with an HC1 solution. Such parameters as combustion temperature(Tc), U, Am, and milling time(τ) were found to affect the tungsten particle size and morphology.

Effect of the gap distance on the cooling behavior and the microstructure of indirect squeeze cast and gravity die cast 5083 wrought Al alloy

Abstract An indirect squeeze casting process applied to a wrought 5083 Al alloy (Al–4.7Mg–0.7Mn) was investigated experimentally and numerically. A two-dimensional finite element computer code for fully coupled heat transfer and deformation analysis, abaqus , was used to simulate the cooling curves obtained from the experiments. Thermal contraction of the material during solidification creates an air gap between the mold and the cooling material. The formation of this air gap is explained using the calculated results. The experimental and predicted results are discussed in conjunction with the relationships between the cooling rate, microstructure, die geometry and applied pressure. The effect of applied pressure and cooling rate on the macrosegregation is also discussed.

The analysis of PM2.5 and associated elements and their indoor/outdoor pollution status in an urban area

UNLABELLED In this study, elemental composition of PM2.5 and the status of indoor/outdoor pollution were investigated in a commercial building near a roadside area in Daejeon, Korea. A total of 60 parallel PM2.5 samples were collected both on the roof (outdoor) and in an indoor office of a building near a highly congested road during the spring and fall of 2008. The concentrations of 23 elements were analysed from these PM2.5 samples using instrumental neutron activation analysis. PM2.5 levels in indoor environment (47.6 ± 16.5 μg/m(3)) were noticeably higher than the outdoor levels (37.7 ± 17.2 μg/m(3)) with the I/O concentration ratio of 1.37 ± 0.33 [correlation coefficient (r) = 0.89, P < 0.001]. Principal component analysis results coincidently showed the predominance of sources such as soil dust, traffic, oil/coal combustion and road dust for both indoor and outdoor microenvironments. An isolated source in the indoor environment was assigned to environmental tobacco smoke (ETS) with high factor loading of Ce, Cl, I, K, La and Zn. The overall results of our study indicate that the sources of indoor constituents were strongly dependent on outdoor processes except for the ones affected by independent sources such as ETS. PRACTICAL IMPLICATIONS An improved understanding of the factors affecting the indoor PM2.5 concentration levels can lead to the development of an efficient management strategy to control health risks from exposure to indoor PM2.5 and related toxic components. A comparison of our comprehensive data sets indicated that most indoor PM2.5 and associated elemental species were strongly enriched by indoor source activities along with infiltration of ambient outdoor air for a naturally ventilated building.

Stromelysin‐3 expression in the differential diagnosis of dermatofibroma and dermatofibrosarcoma protuberans: comparison with factor XIIIa and CD34

Background The distinction between dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) is a well‐known challenge for dermatopathologists. Immunohistochemical stains have been used to augment routine histological examination to aid in differentiating DF from DFSP. Stromelysin‐3 (ST3) is a member of the matrix metalloproteinase (MMP) family, MMP‐11, which is expressed in the skin during wound healing and in the stroma of basal cell carcinoma. Recent studies demonstrated that DFs expressed ST3, whereas DFSPs were only rarely ST3 positive.

QTL analysis of white blood cell, platelet and red blood cell-related traits in an F2 intercross between Landrace and Korean native pigs

Haematological traits play important roles in disease resistance and defence functions. The objective of this study was to locate quantitative trait loci (QTL) and the associated positional candidate genes influencing haematological traits in an F(2) intercross between Landrace and Korean native pigs. Eight blood-related traits (six erythrocyte traits, one leucocyte trait and one platelet trait) were measured in 816 F(2) progeny. All experimental animals were genotyped with 173 informative microsatellite markers located throughout the pig genome. We report that nine chromosomes harboured QTL for the baseline blood parameters: genomic regions on SSC 1, 4, 5, 6, 8, 9, 11, 13 and 17. Eight of twenty identified QTL reached genome-wide significance. In addition, we evaluated the KIT locus, an obvious candidate gene locus affecting variation in blood-related traits. Using dense single nucleotide polymorphism marker data on SSC 8 and the marker-assisted association test, the strong association of the KIT locus with blood phenotypes was confirmed. In conclusion, our study identified both previously reported and novel QTL affecting baseline haematological parameters in pigs. Additionally, the positional candidate genes identified here could play an important role in elucidating the genetic architecture of haematological phenotype variation in swine and in humans.

Continuous-wave operation of 1.5μm InGaAs∕InGaAsP∕InP quantum dot lasers at room temperature

Continuous-wave operation at room temperature from InGaAs∕InGaAsP∕InP quantum dot (QD) laser diodes (LD) has been achieved. A ridge waveguide QD LD with 7 QD-stacks in the active region lases at 1.503μm at 20°C and that with 5 QD-stacks lases at 1.445μm at room temperature. The shift in lasing wavelength is believed to be due to the difference in the quantized energy states involved in producing gain for lasing. With smaller number of QD stacks and shorter cavity length, the lasing wavelength shifts to shorter wavelength indicating that more of higher excited states are involved in producing gain. By increasing the number of QD stacks to 15, lasing at 1.56μm has been achieved under pulsed mode.

Sequence-based characterization of swine leucocyte antigen alleles in commercially available porcine cell lines.

A total of 53 alleles at five highly polymorphic swine leucocyte antigen (SLA) loci (SLA‐1, SLA‐3, SLA‐2, SLA‐DRB1, and SLA‐DQB1) were identified in eight commercially available porcine cell lines (ESK‐4, LLC‐PK1, MPK, PK13, PK15, PT‐K75, SK‐RST, and ST). This information is essential for the use of these cell lines to understand the role of SLA genes and proteins in swine models of transplantation, xenotransplantation, and in swine immune responses to infectious diseases and vaccines. The ready availability of these cell lines also makes them a good source of reference DNA for SLA allele typing.