• 한국임상약학회지
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• 제16권1호
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• pp.52-56
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• 2006

Aceclofenac, a nonsteroidal antiinflammatory agent of a phenylacetic acid type, has been used for rheumatoid arthritis and osteoarthrits. Although the metabolic pathway of aceclofenc is relatively well-known in vitro, pharmacokinetic profiles of its three major or metabolites are still unclear in human. The present study was designed to investigate pharmacokinetic profiles of the metabolites of aceclofenac, and to evaluate the bioequivalence of the generic preparation of aceclofenac 100 mg tablet. Blood samples were serially collected for a period of 12 hours following a single oral administration of 100 mg aceclofenac in 20 healthy human volunteers. A simple protein precipitation with acetonitrile was employed to purify those substances from plasma. Aceclofenac, diclofenac, 4'-hydroxyaceclofenac and 4'-hydroxy-diclofenac in heparinized plasma were simultaneously measured with flufenamic acid, an internal standard, using HPLC coupled to a tandem mass spectrometer. Time courses of 4'-hydroxydiclofenac, diclofenac and aceclofenac plasma concentrations were clearly revealed, and the pharmacokinetic properties were analyzed. The 90% confidence intervals for the ratios of test/reference for log-transformed AUC and $C_{max}$ lie within 0.80-1.25.

• Journal of Power Electronics
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• 제16권5호
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• pp.1851-1860
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• 2016

The traction motors in electric multiple unit (EMU) trains are powered by AC-DC-AC converters, and the DC link voltage is generated by single phase PWM converters, with a fluctuation component under twice the frequency of the input catenary AC grid, which causes fluctuations in the motor torque and current. Traditionally, heavy and low-efficiency hardware LC resonant filters parallel in the DC side are adopted to reduce the ripple effect. In this paper, an analytical model of the ripple phenomenon is derived and analyzed in the frequency domain, and a ripple control scheme compensating the slip frequency of rotor vector control systems without a hardware filter is applied to reduce the torque and current ripple amplitude. Then a relatively simple discretization method is chosen to discretize the algorithm with a high discrete accuracy. Simulation and experimental results validate the proposed ripple control strategy.

• 열처리공학회지
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• 제27권4호
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• pp.180-184
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• 2014

In order to make clear relationship between high temperature tensile properties and fine microstructure of rapidly solidified cast-type Ni-base superalloys without heat treatment required for consolidation process, tensile test was carried out by changing strain rate from $5{\times}10^{-5}s^{-1}$ to $2{\times}10^{-2}s^{-1}$ and test temperature from $900^{\circ}C$ to $1050^{\circ}C$ using IN738LC and Rene'80 melt-spinning ribbons by twin roll process which were superior to ribbons by single roll process from the viewpoint of structure homogeneity. The dependence of tensile strength on strain rate and test temperature was studied and strain rate sensitivity, m, were estimated from tensile test results. From this study, it was found that tensile strength was influenced by ${\gamma}^{\prime}$ particle diameter, test temperature and strain rate, and m of ribbons exhibited above 0.3 over $950^{\circ}C$.

• Food Science and Biotechnology
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• 제18권2호
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• pp.396-401
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• 2009

The nucleotide sequence contains 2 open reading frames encoding a 45-amino-acid protein homologous to a transcriptional repressor protein CopG, and a 203-amino-acid protein homologous to a replication protein RepB. Putative countertranscribed RNA, a double-strand origin, and a single-strand origin were also identified. A shuttle vector, pUCL2.1, for various lactic acid bacteria (LAB) was constructed on the basis of the pCL2.1 replicon, into which an erythromycin-resistance gene as a marker and Escherichia coli ColE1 replication origin were inserted. pUCL2.1 was introduced into E. coli, Lc. lactis, Lactobacillus (Lb.) plantarum, Lb. paraplantarum, and Leuconostoc mesenteroides. The recombinant LAB maintained traits of transformed plasmid in the absence of selection pressure over 40 generations. Therefore, pUCL2.1 could be used as an E. coli/LAB shuttle vector, which is an essential to engineer recombinant LAB strains that are useful for food fermentations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1207-1208
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• 2006

Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system. It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system. Therefor, this paper, consists of an isolated DC-DC converter to boost the fuel cell voltage 380[VDC] and a PWM inverter with LC filter to convent the DC voltage to single-phase 220[VAC]. Expressly, a tapped inductor filter with freewheeling diode is newly implemented in the output filter of the proposed high frequency isolated ZVZCS PWM DC-DC converter to suppress circulating current under the wide output voltage regulation range, thus to eliminate the switching and transformer turn-on/off over-short voltage or transient phenomena. Besides the efficiency of 93-97[%] is obtained over the wide output voltage regulation ranges and load variations.

• Archives of Pharmacal Research
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• 제28권10호
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• pp.1177-1182
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• 2005

The hepatotoxic effects of 1-bromopropane (1-BP) and its conjugation with glutathione were investigated in male ICR mice. A single dose (1000 mg/kg, po) of 1-BP in corn oil to mice significantly increased serum activities of alanine aminotransferase and aspartate aminotransferase. Glutathione (GSH) content was dose-dependently reduced in liver homogenates 12 h after 1-BP treatment. In addition, 1-BP treatment dose-dependently increased levels of S-pro-pyl GSH conjugate at 12 h after treatment, as measured by liquid chromatography-electro-spray ionization tandem mass spectrometry. The GSH conjugate was maximally increased in liver at 6 h after 1-BP treatment (1000 mg/kg), with a parallel depletion of hepatic GSH content. Finally, 1-BP induced the production of malondialdehyde in liver. The present results suggest that 1-BP might cause hepatotoxicity, including lipid peroxidation via the depletion of GSH, due to the formation of GSH conjugates in male ICR mice.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권4호
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• pp.511-519
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• 2016

This paper proposes a CMOS 6-bit phase shifter with low RMS phase and amplitude errors for an X-band phased array antenna. The phase shifter combines a switched-path topology for coarse phase states and a switch-filter topology for fine phase states. The coarse phase shifter is composed of phase shifting elements, single-pole double-throw (SPDT), and double-pole double-throw (DPDT) switches. The fine phase shifter uses a switched LC filter. The phase coverage is $354.35^{\circ}$ with an LSB of $5.625^{\circ}$. The RMS phase error is < $6^{\circ}$ and the RMS amplitude error is < 0.45 dB at 8-12 GHz. The measured insertion loss is < 15 dB, and the return losses for input and output are > 13 dB at 8-12 GHz. The input P1dB of the phase shifter achieves > 11 dBm at 8-12 GHz. The current consumption is zero with a 1.2-V supply voltage. The chip size is $1.46{\times}0.83mm^2$, including pads.

• Restorative Dentistry and Endodontics
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• 제27권5호
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• pp.521-529
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• 2002

The purpose of this study was to compare the shaping time of two shaping methods and the leakage of three different obturation techniques. Ninty three canaled human molar teeth were used, which were randomly divided into two groups of forty teeth each and ten control teeth. After working length determination, the one group was prepared crown-down technique using rotary root canal instruments of GT rotary files .12/20, .10/20, .08/20 and .06/20 taper(Maillefer Instrument SA. Switzerland). The other group was instrumented with Gates Glidden burs(#1, #2, and #3) to coronal preparation and GT rotary files .08/20 and .06/30 taper to apical preparation. Shaping time was measured. After root canals were instrumented, they were divided to three subgroups and obturated as follows : Subgroup 1, obturated with single cone method Subgroup 2, obturated with lateral condensation : Subgroup 3, obturated with continuous wave technique. Three subgroups were obturated using non-standardized gutta-percha cone(Diadent, Korea, .06 or .08 taper) and AH-26(Dentsply DeTrey, Germany) as a root canal cement. Ten unobturated teeth served as positive and negative controls. After immersion in 2% methylene blue solution for 1 month, the teeth were washed during 24h. The teeth were demineralized in 10% nitric acid and dehydrated by immersion in 80, 90 and 100% ethyl alcohol. The teeth were finally cleared and stored in 100% methylsalicylate, and apical dye penetration was evaluated under stereomicroscope(Leica M420, LC, U.S.A)at $\times$8.75 magnification. Liner measurement of dye penetration was assessed with the use of digitalized image analysing system (analySIS, GmbH, Germany) The data were analysed statistically using independent T-test and Two-way ANOVA and Tukey test. The result were as follows 1. In canal prepared with GT$^{TM}$ rotary file, shaphing time taked more than the group of using Gates Glidden drill to coronal preparation without statistical significance (p>0.05) 2. The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files showed significantly more apical leakage than those of lateral condensation and continuous wave technique regardless of shaping method (p<0.05). 3 The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files and Gates Glidden drill showed significantly more apical leakage than those of continuous wave technique regardless of shaping method (p<0.05). 4. Regardless of shaping method, The group of continuous wave obturation showed less apical leakage than those of lateral condensation without statistical significance (p>0.05). 5. The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files and Gates Glidden drill showed more apical leakage than the group of lateral condensation using same shaping method with-out statistical significance (p＞0.05).

• 한국발생생물학회지:발생과생식
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• 제13권2호
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• pp.105-114
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• 2009

알킬화제로 잘 알려진 ethane 1,2-dimethane sulfonate(EDS)는 여러 종에서 선택적인 Leydig 세포(LC) 독성과 정소 기능장애에 연구 모델로 널리 사용된다. EDS 투여에 의해 유도된 LC 녹아웃 흰쥐의 경우, 부정소와 저정낭과 같은 테스토스테론 의존성 부속 생식기관들의 급격한 무게 감소가 초래됨이 이전의 연구들에게 보고되었다. 본 연구는 EDS투여가 흰쥐 부속 생식기관에 미치는 영향에 대해 조사한 것이다. 생체 수컷 흰쥐에 EDS를 1회 주사(75 mg/kg, i.p.)한 후 0, 1, 2, 3, 4, 5, 6, 7주 후에 각각 희생시겼다. 정소와 부정소, 저정낭 그리고 전립선의 무게를 각각 측정하였다. 조직의 변화는 hematoxylin & eosin 염색과 광학현미경을 통하여 분석하였다. 생식소와 그 부속기관의 무게는 EDS 처리 후 3주 까지는 점진적으로 감소하였고, 이후 서서히 정상으로 회복되었다. 부정소의 무게는 정상 수준의 60%까지 회복되는 양상을 보였다. 조직학적 결과에서 부정소의 상피세포층은 주사 후 1주에서 3주까지 비대해지는 것이 관찰되었다. 저정낭에서는 주사 후 1주부터 3주까지 상피세포층의 두께가 감소하였다. 전립선 역시 주사 후 1주에서 3주까지 상피세포층의 두께가 감소되고, 4주부터 회복되었다. 본 연구는 EDS 주사에 의해 일시적으로 안드로겐 결핍이 일어난 흰쥐에서 부속 생식기관에 뚜렷한 조직학적 변화가 일어남을 보였다. EDS 모델을 사용하여 이들 안드로겐 의존적인 부속 생식기관의 생리적, 분자적인 조절 기작에 대해 심층 연구할 경우 이들 조직의 정상 및 병리학적 발생과 분화를 이해하는데 도움이 될 것이다.

• 한국발생생물학회지:발생과생식
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• 제10권3호
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• pp.203-209
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• 2006

Ethane 1,2-Dimethane sulfonate(EDS)은 Leydig cells(LC)만을 선별적 사멸을 유도하는 약물로서 가역적인 테스토스테론 결핍 흰쥐 모델을 만드는데 널리 사용된다. EDS 투여에 의해 유도된 'LC 녹아웃' 흰쥐의 경우 부정소와 저정낭과 같은 테스토스테론 의존성 부속 생식기관들의 급격한 무게 감소가 초래됨이 이전의 연구들에서 보고되었는데, 이러한 무게 감소의 상당 부분은 세포자연사에 의한 것으로 보인다. 본 연구는 흰쥐 부정소에서 세포자연사 관련 유전자들의 발현에 미치는 EDS 투여 효과를 조사한 것이다. 성숙한 수컷 흰쥐(SD strain, $300{\sim}350\;g\;B.W.$)에 EDS(75 mg/kg, i.p.)를 1회 복강주사하고 주사 후 0, 1, 2, 3, 4, 5, 6 그리고 7주가 경과한 날 희생시켰다. 희생 직후 조직 무게와 부정소 미부의 정자수를 측정하였다. 부정소로부터 total RNA를 추출한 후 세포자연사 관련 유전자들 가운데 bcl-2, bax, Fas 그리고 Fas ligand(Fas-L)의 발현 변화를 semi-quantitative RT-PCR로 측정하였다. 예상한 바처럼, 부정소 무게와 정자 수는 EDS 주사 후 $1{\sim}2$주 동안에 급격히 감소하였다. 이후 어느 정도 회복하였지만, 최종적으로 주사 후 7주경 부정소 무게(71%)와 정자 수(38%) 모두 최초 수준에는 미달하였다. 부정소에서의 bcl-2 전사 수준은 주사 직후부터 6주 후까지 지속되다가 주사 후 7주에 유의하게 상승하였다. 또한 bax 전사 수준은 주사 후 6주에 유의하게 감소하였으며 나머지 전 기간 동안에는 별다른 차이가 없었다. 한편 Fas 전사 수준은 EDS 주사 후 $1{\sim}2$ 주간 상승하였다가 주사 후 3주부터 정상 수준으로 감소하여 7주까지 지속되었다. 유사하게, Fas-L의 전사 수준도 주사 후 $1{\sim}3$주 동안 상승하였다가 주사 후 4주부터 정상 수준으로 복귀하였다. 본 연구의 결과는 EDS 주사가 흰쥐 부정소에서의 세포자연사 관련 유전자 발현을 유도할 가능성을 보여준 것이며, 특히 Fas와 Fas-L 유전자 활성이 초기 세포자연사 유도 과정에 중요하고, 그 결과로 부정소 무게 감소와 정자 수 감소가 초래되는 것으로 추정된다.