• Bulletin of the Korean Chemical Society
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• v.17 no.10
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• pp.909-918
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• 1996

Syntheses of carbapenam skeletons were achieved from 1,3-propanediol through 1,3-dipolar cycloaddition. 3-(Tetrahydropyran-2-yloxy)-(10) and 3-(t-butyldimethylsilyloxy) propanal (13) were obtained from 1,3-propanediol. 3-Hydroxypropanals (10, 13, 14) were reacted with N-hydroxyglycine esters to give C-(2-hydroxyethyl)-N-alkoxycarbonylmethylnitrones (15a-15d). 1,3-Dipolar cycloaddition of the nitrones with methyl acrylate or ethyl crotonate gave 3-(2-hydroxyethyl)isoxazolidines (16a-16b, 17a-17b, 18, 19a-19b). 3-(2-Hydroxyethyl)isoxazolidines (17a, 17c, 19a, 19b) were converted to 3-(2-iodoethyl)isoxazolidines (21a-21d) or 3-phenylthiocarbonylmethylisoxazolidines (25a-25d) which were cyclized to give 2-oxa-1-azabicyclo[3.3.0]octanedicarboxylates (22a-22d, 26a-26d). 2-Oxa-1-azabicyclo[3.3.0]octane-4,8-dicarboxylates (22c-22d, 26c-26d) were transformed to 6-(l-hydroxyethyl)carbapenam-3-carboxylates (30a-30b, 31a-31b).

• Journal of Magnetics
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• v.5 no.4
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• pp.124-129
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• 2000

$Sm_2Fe_{17}N_x$ film magnets were prepared using a $Sm_2Fe_{17}$ target in a $N_2$ gas atmosphere using a Nd-YAG pulsed laser ablation technique. The effect of nitrogen pressure, deposition temperature, pulse time and film thickness on the structure and magnetic properties of $Sm_2Fe_{17}N_x$ film were studied. Increasing the nitrogen pressure up to 5 atm led to the formation of complete $Sm_2Fe_{17}N_x$ compound. Optimized magnetic properties with the nitrogenation temperature in the range 500-53$0^{\circ}C$ could be obtained by extending the nitrogenation time up to 4 hours. Relatively low coercivities of 400~600 Oe were found in $Sm_2Fe_{17}N_x$films 50~100 m thick, while a $4\piM_s$ of 10$\sim$12 kG could be achieved. In-plane anisotropy, which was the basic goal in this study, was achieved by controlling the nitrogenation parameters.

• Hanyang Medical Reviews
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• v.33 no.1
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• pp.27-32
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• 2013

Inflammatory bowel diseases(IBD), including Crohn's disease and ulcerative colitis, are chronic inflammatory states of the intestinal tract. While the exact mechanisms inducing chronic inflammation are still unclear, it is hypothesized that the inflammation is caused in part by an inappropriate immune response to the intestinal microflora. Although inflammatory diseases are not directly linked to patient survival, symptoms of these diseases significantly decrease quality of life. The incidence rate is higher in western people than eastern people, but the incidence rate of IBD in eastern people, including Korean, is increasing. Recently, it has been reported that IL-17 is an important factor that appears to be involved in IBD induction and progression. This report reviews many recent papers reporting the relationship between IBD and IL-17, which may provide an understanding leading to new means of prevention and treatment for IBD.

• The Journal of the Korean Society for Microbiology
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• v.12 no.1
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• pp.19-32
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• 1977

The specificity of the N- and C-terminal antigenic determinant($P_{17}$: sequence $Lys^1-{cys-}^6-Asn^{27},\;{Trp^{12}}_2-Cys^{127}-Leu^{129}$) of hen egg-white lysozyme(HL) was studied in more detail. In a Scatchard plot of the binding of $^{14}C$-acetyl HL with guinea pig purified anti-$P_{17}$ antibody experimental values bent sharply aear r=1. This suggests of two antibody populations with different affinities for HL or possible steric hindrance in the binding of a second HL molecule to the second binding site of the antibody molecule. The antigenic activities of various peptides were tested by measuring their inhibition of the binding of $^{14}C-acetyl-P_{17}$ with the antibody, Only $P_{17}$ and $P_{17}t$(sequence $Lys^1-cys^6-Homoser^{12},\;Trp^{123}-Cys^{127}-Leu^{128})$) were inhibitory, with $K_1$ values of $2.0{\times}10^4$ and $8.1{\times}10^3$, respectively. These results indicate that the direct binding site of $P_{17}$ to anti-$P_{17}$ antibody may be located in the terminal portion of $P_{17}$ (sequence $Lys^1-Cys^6-Homoser^{12},\;Trp^{123}-Cys^{127}-Leu^{129})$) while the rest of $P_{17}$ may be important in maintaining the conformation of this determinant. The single disulphide bond involved in this determinant is essential for manifestation of immunological activity.

• Science & Technology Policy
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• v.1 no.1 s.1
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• pp.17-17
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• 1991

STEPI(과학 기술 정책 연구소)는 1987년 창설 이래 정책 연구 과제 17건과 기본 연구 과제 6건 등을 당 연구소 연구 팀 및 외부 전문가를 활용 수행하였으며, `91년 현재 완료된 중요 연구 과제와 수행중인 연구 과제는 아래와 같다.

• NEWSLETTER 전기공업
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• no.91-17 s.30
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• pp.1-17
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• 1991

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.02a
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• pp.17-17
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• 2003

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.83-88
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• 2018

Additive manufacturing (AM) technologies have attracted wide attention as key technologies for the next industrial revolution. Among AM technologies using various materials, powder bed fusion (PBF) processes and direct energy deposition (DED) are representative of the metal 3-D printing process. Both of these processes have a common feature that the laser is used as a heat source to fabricate the 3-D shape through melting of the metal powder and solidification. However, the material properties of the deposited metals differ when produced by different process conditions and methods. 17-4 precipitation-hardening stainless steel (17-4PH SS) is widely used in the field of aircraft, chemical, and nuclear industries because of its good mechanical properties and excellent corrosion resistance. In this study, we investigated the differences in microstructure and mechanical properties of deposited 17-4PH SS by PBF and DED processes, including the heat treatment effect.

• Korean Journal of Animal Reproduction
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• v.15 no.2
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• pp.117-124
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• 1991

This stduy was conducted to find out the changes of estradiol-17$\beta$ and progesterone levels in the plasma of Cheju mares during gestatation period and before and after parturition with 12 heads of Cheju ponies. The results are as follows : 1. The estradiol-17$\beta$ and progesterone levels on the 1~4 months showed 61.6~134.2pg/ml and 7.74~9.20ng/ml respectively, but the estradiol-17$\beta$ levels rapidly increased to 426.4~1772.9pg/ml, and the progesterone levels decreased to 1.42~5.43ng/ml on the 5~10 months of gestation period. 2. The progesterone levels of the pregnant and the non-pregnant mares showed 4.80ng/ml and 0.04ng/ml in winter, respectively, but both of the two appeared 1,211.5pg/ml and 99.4pg/ml of estradiol-17$\beta$, respectively. Therefore the diagnosis of pregnancy might be more accurate with the levels of estrdiol-17$\beta$ in autumn. 3. The progesterone levels showed 3.20ng/ml the day before parturition and less than 1ng/ml on 2 days after parturition. The estradiol-17$\beta$ levels, showing the rising trend, and 90.1~162.4pg/ml up to 10 days.

• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1628-1634
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• 2009

Small heat shock proteins (sHSPs) function as molecular chaperones that protect cells against environmental stresses. In the present study, the genes of hsp17.6 and hsp17.7, cytosolic class I sHSPs, were cloned from a tropical plant, Ageratina adenophorum. Their C-terminal domains were highly conserved with those of sHSPs from other plants, indicating the importance of the C-terminal domains for the structure and activity of sHSPs. The recombinant HSP17.6 and HSP17.7 were applied to determine their chaperone function. In vitro, HSP17.6 and HSP17.7 actively participated in the refolding of the model substrate citrate synthase (CS) and effectively prevented the thermal aggregation of CS at $45^{\circ}C$ and the irreversible inactivation of CS at $38^{\circ}C$ at stoichiometric levels. The prior presence of HSP17.7 was assumed to suppress the thermal aggregation of the model substrate CS. Therefore, this report confirms the chaperone activity of HSP17.6 and HSP17.7 and their potential as a protectant for active proteins.