• Analytical Science and Technology
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• v.15 no.4
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• pp.346-359
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• 2002

The brominated flame retardants (BFRs) are one of the unregulated pollutants in Korea, which is recently highlighted the new pollutants of environmental contamination. In this study, the previous research papers related the BFRs were surveyed, and the analytical methods of BFRs were established. The results are followed; The 40 kinds of PBDEs standards were used to establish the analytical methods to perform the experiments of recoveries and detection limits in water and soil. The detection limits of PBDEs using GC/MS represented 5.0~10.0 pg/L for water and 0.5~2.0 ng/g for soil samples. The average recoveries of water samples were 89~98% with ethylacetate, n-hexane and dichloromethane, and 89~103% in combined solvent with n-hexane and acetone. In soxhlet extraction, the higher recoveries obtained the acetone:n-hexane(1:1) comparing with acetone:dichloromethane(1:1).

• Archives of Pharmacal Research
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• v.27 no.2
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• pp.239-245
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• 2004

KR-31543, (2S,3R,4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2 -methyl-2H-tetrazol-5-ylmethyl) amino]-3,4-dihydro-2-dimethoxymethyl-3-hydroxy-2-methyl-2H-1-benzopyran, is a new neuroprotective agent for preventing ischemia-reperfusion damage. This study was performed to identify the metabolic pathway of KR-31543 in human liver microsomes and to characterize cytochrome P450 (CYP) enzymes that are involved in the metabolism of KR-31543. Human liver microsomal incubation of KR-31543 in the presence of NADPH resulted in the formation of two metabolites, M1 and M2. M1 was identified as N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amine on the basis of LC/MS/MS analysis with a synthesized authentic standard, and M2 was suggested to be hydroxy-KR-31543. Correlation analysis between the known CYP enzyme activities and the rates of the formation of M 1 and M2 in the 12 human liver microsomes have showed significant correlations with testosterone 6$\beta$-hydroxylase activity (a marker of CYP3A4). Ketoconazole, a selective inhibitor of CYP3A4, and anti-CYP3A4 monoclonal antibodies potently inhibited both N-hydrolysis and hydroxylation of KR-31543 in human liver microsomes. These results provide evidence that CYP3A4 is the major isozyme responsible for the metabolism of KR-31543 to M1 and M2.

• Clinical and Experimental Reproductive Medicine
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• v.22 no.2
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• pp.149-153
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• 1995

In IVF-ET program, intracytoplasmic sperm injection(ICSI) has been performed with testicular sperm extraction(TESE) in case of no normal spermatozoon could be retrieved from the epididymis. We wished to see whether the quality of testicular sperm affect the fertilization and pregnancy rate in TESE-ICSI cycles(n=40). These cycles were classified into three groups by the total number of normal motile spermatozoa(TNMS) in the TESE sample: i) good sperm(GS) group(n=12), TNMS > 10,000; ii) moderate sperm(MS) group(n=19), 1,000 < TNMS < 10,000; iii) poor sperm(PS) group(n=9), TNMS < 1,000. Among 423 injected oocytes, 307(72.6%) oocytes were normally fertilized and 43 zygotes were cryopreserved. The fertilization rates of GS group(79.3%) and MS group(75.9%) were significantly(p<0.005) higher than PS group(60.2%). After the embryo transfer(n=40), clinical pregnancy was obtained in 14 cycles(35.0%) and on-going pregnacy in 13 cycles(32.5%). The clinical and on-going pregnancy rates were similar in each group. From these results it can be concluded that testicular spermatozoa are successfully used with ICSI in IVF-ET program in spite of very poor quality of TESE sample.

• Economic and Environmental Geology
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• v.54 no.6
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• pp.629-647
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• 2021

Located in the eastern part of the Anti-Atlas, the Tafilalet region shows numerous dykes and sills that crosscut the Paleozoic terrains. The magmatic structures (dykes and sills) of the Tadaout-Tizi n'Rsas (TTR) anticline is studied here, it located neighboring the main branch of the Anti-Atlas Major Fault (AAMF), known in this location as the Oumejrane-Taouz Fault (OJTF). The N20° to N60° trending dykes crosscut the Paleozoic formations (Ordovician to Devonian), whereas sills are injected into the Silurian and Devonian ones. The dyke swarms of TTR have been studied using the Anisotropy of Magnetic Susceptibility (AMS), petrographic study and structural analyses. The petrographic study of the TTR doleritic dykes shows a dominance of plagioclase feldspars, alkali feldspars, amphiboles, pyroxenes and biotite. The dykes contain also mesotype (natrolite), sphene (titanite), apatite, actinolite and pegmatitic enclaves of biotite, orthoclase feldspars and pelites. Concerning field works, they show the deformation of TTR dykes by the Variscan tectonics events, it is marked by the presence of displacements (strike-slip faults) and cleavages. The Magnetic Susceptibility (MS) measured on magmatic specimens show the dominance of ferromagnetic and paramagnetic minerals. The high values of MS in the dykes are due to the presence of hematite, amphibole, pyroxene and biotite. In addition their magnetic fabric, determined by our AMS study, allows us to reconstitute the tectonic event which affected the magmatic bodies. This one is characterized by a magnetic foliation and a NNW-trending lineation that reflect the Variscan shortening orientation.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.415.3-416
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• 2002

To improve the stability of recombinant human epidermal growth factor (rhEGF) as therapeutic agent. the N-terminal PEGylated rhEGF (N-PEG-rhEGF) was prepared by site-specific bioconjugation and the stability was investigated in rat skin wound homogenates. Two different N-PEG-rhGEFs (N-PEG5K- and N-PEG20K-rhEGF) were successfully prepared with the yields of above 70%. The PEGylation site was directly confirmed by determining the molecular mass of Lys-C digested samples using MALDI- TOF MS. (omitted)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.303-305
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• 2000

The effect of anisotropy field on the high frequency magnetic characteristics of FeTaN films was investigated. Those films show good magnetic properties : 4$\pi$Ms of 13KG, Hc of 0.6 Oe, effective permeability(${\mu}$') of 800 with a stable frequency response up to 800MHz. The films also show a large anisotropy field(Hk) over 21Oe. It result from the increased anisotropy of patterned FeTaN films. The combination of high saturation magnetization and relatively high Hk in these films is believed to the partly responsible for FeTaN for the excellent high-frequency behavior.

• The Journal of the Acoustical Society of Korea
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• v.4 no.2
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• pp.3.2-3.2
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• 1985

본 논문은 전 전자식 교환기에 사용되는 MFC 수신기를 설계하기 위해서 FIR-Filter를 사용한 논문이다. FIR-filter를 설계함에 있어서, Remetz Algorithm을 사용한 Mellellan의 방식이 적용되었으며 인접주파수를 정확히 구분하기 위하여 85차의 고차필터를 설계하였고, 필터의 출력 데이터 15개의 합으 로써 각 주파수에 대한 판별값으로 정하였다. 인접 주파수를 구분하는 출력 power의 결과는 최근의 FGT-MFC 수신기의 출력 power의 결과와 비교 하였을 때, S/N 비면에서 5dB 이상의 향상을 보였으 며, 133개의 입력데이타를 사용하는 FGT-MFC 수신기보다 4.2ms 빠른 응답특성을 나타냈다.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.683-686
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• 1994

The chemical constituents of Selaginella tamariscina were studied. From the n-hexane, chloroform and n-butanol soluble fractions, three compounds were isolated by chromatographic purification process. They were identified as lutein, $3{\beta}-cholesterol$ and hinokiflavone by spectral anaylsis(IR, MS, UV, $^1H-NMR$, $^{13}C-NMR$ and DEPT). Lutein and $3{\beta}-cholesterol$ were first isolated compounds from Selaginellaceae and hinokiflavone was a reported compound from this plant.

• Journal of Ginseng Research
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• v.8 no.1
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• pp.22-31
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• 1984

Volatile flavor components of fresh ginseng (Panax ginseng C.A. Meyer.) were studied. Steam distillate of fresh ginseng was extracted with ethyl ether and the extract was separated into four fraction: neutral, phenolic, acidic and basis fractions. The ethyl ether concentrates and neutral fraction were analyzed by a combination of SE-54 fused silica capillary gas chromatography and mass spectrometry. Major flavor components of fresh ginseng were predominantly mono(n +2) and sesquiterpenes(n +3) in over two hundred constituents. Of these, 28 were newly identified in volatile flavor components of fresh ginseng by GC-MS.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.11a
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• pp.168-170
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• 2001

생물 계면활성제의 개발을 위해 MNNG(N-Methyl-N-Nitro- Nitrosoguanidine), EMS, UV radiator random mutation을 통해 가장 우수한 biosurfactant 생산 균주를 선별하였는데 MNNG를 처리한 균주가 유화활성 1.950, 표면장력 29.0dyne/cm으로 공시균주인 Pseudomonas aeruginosa EL-MS 유화활성 0.456과 표면장력 33.0dyne/cm에 비해 우수하였다.