• Korean Chemical Engineering Research
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• 제50권5호
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• pp.879-884
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• 2012

본 실험에서는 Aspergillus niger NRRL 567의 고체배양을 이용한 구연산 생산 시, 물리/화학적 발효 조건인 배양 온도, 배지 pH, 접종 농도 및 수분 함량이 구연산 생산에 미치는 영향을 단일변수(one-factor-at-a-time)와 반응표면 분석법(surface response methodology)을 이용하여 순차적 최적화를 수행하였다. 단일변수 최적화의 경우, A. niger에 의한 구연산 생산은 물리/화학적 발효 조건에 의해 영향을 받으며, 발효 온도 $30^{\circ}C$, 영양 배지 pH 7.1, 수분 함량 75%와 접종 농도 $4.0{\times}10^6$ spores/ml에서 최대 구연산 생산인 98.2 g/kg DPM (dry peat moss)을 보였다. 단일변수 최적화에 근거하여 반응표면 분석법을 도입하여 2차 최적화를 수행했을 경우, 배지 pH와 수분 함량이 구연산 생산에 유의한 영향을 주었으며 온도 $26.5^{\circ}C$, 영양 배지 pH 9.9, 수분 함량 75.1%와 접종 농도 $6.0{\times}10^6$ spores/ml에서 최대 구연산 생산인 118.8 g/kg DPM가 얻어졌다. 이는 최적화 이전의 대조군에 비해 구연산 생산이 1.6배 증가한 결과이다.

• Journal of Periodontal and Implant Science
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• 제28권4호
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• pp.677-692
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• 1998

In order to study the effects of cigarette smoking on periodontal tissue, gingival fibroblast from the smoking and nonsmoking groups were cultured and each group were treated with nicotine(50ng/ml,100ng/ml) and NNK(50ng/ml, 100ng/ml) to test their attachment ability at time intervals of 30minutes, 60minutes, 90minutes, 120minutes, and 240minutes. Using the same method, the growth each group treated with nicotine and NNK in order to compare their attachment ability and growth rate was done. The Results are as follows. 1. In comparing the attachment ability and growth rate between the smoking and non-smoking group were significantly higher in all time intervals. 2. When the attachment ability was com-pared among these two groups after treatment with nicotine and NNK, the non-smoking group showed decrease in attachment ability while the smoking group was not affected. 3. The growth rate of these two groups were compared after treating with nicotine and NNK. The growth rate of fibroblast from the non-smoking group decreased while fibroblast from the smoking group was not affected. These results suggest that fibroblast from the non-smoking group showed higher attachment ability, growth rate, and sensitivity to nicotine and NNK. This implies that fibroblast from the non-smoking group is a more reliable source in testing the cytotoxicity of nicotine and NNK. Also it could be reasonable to think that nicotine and NNK is a probable cause for problems in attachment and repair mechanism.

• 한국환경농학회지
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• 제14권1호
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• pp.45-54
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• 1995

esters of the acid analytes were synthesized using $H_2SO_4$ as the catalyst. Efficiency of derivatization and instrumental molecular-response were compared with herbicides methylated with $BF_3-methanol$(14% W/V), $H_2SO_4-methanol$(33% V/V), and diazomethane. The molecular integrity of TFE-2,4-D, TFE-dicamba, and TFE-mecoprop, in the mixture, was confirmed by the GC/MSD method. The TFE-Esterification efficiency was maximized by adjusting the volume of $H_2SO_4$ the reaction time, and temperature. Optimal efficiency for the herbicide mixture was obtained by adding 1 ml of $H_2SO_4$ and 1 ml of TFE to the dried sample and allowing the reaction to proceed at $22^{\circ}C$ for 8 hr or using 0.5 ml $H_2SO_4$ and 1 ml of TFE at $60^{\circ}C$. For 120 min increasing the temperature and decreasing the reaction time were required for maximum esterification efficiency. The sensitivity of the GC/ECD to the TFE esters was about $2{\sim}20$ times greater than that to the methyl ester derivatives. The herbicides were extracted and esterified to TFE derivatives simultaneously from soil leachates previously spiked with the analytes. Herbicide recovery, peak resolution, and detector sensitivity were excellent without using column cleanup procedures.

• 환경위생공학
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• 제5권2호
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• pp.63-80
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• 1990

A sensitive and simple analytical system for the simultaneous determination of residual oxytetracycline, tetracycline, and doxycycline in honey was described, and that the analytical method for determination of residual propionic acid in honey was established. Experimental subjects were purchased four kinds of honey, native kind honey, acaccia honey, mixed floral honey, chestnut honey in Kyung Sang Nam Do. Several microbiological methods are available to determine tetracycline antibiotecs(TCs) in foods but their precision apears to be variable and the specificity is questionable. These methods are considered to be not suitable for analysis of tetracycline antibiotics in honey because honey itself has bacteriostatic action. For determination of tetracycline antibiotics in honey, therefore the High Performance Liquid Chromatography(HPLC) method was applied, and the propionic acid were determined by Gas Chromatography(5.C). Ethylacetate, as an extract solvent, was found to be suitable for seperation of TCs in honey, but methanol and acetone were not. The recoverly rate of Oxytetracycline(OTC), Tetracycline(TC), Doxycycline(DC) from honey spiked at a level of 10 $\mu $g/g were 97%, 89%, and 91%, respectively. The cailbration curve in TCs was linear expression from 2$\mu $g/ml to 10$\mu $g/ml. As the results of analysis, the residual tetracycline antibiotics were not detected in the 100 samples of honey. The recovery rate of propionic acid from honey spiked at level of 10$\mu $g/g was 98.3% , and the calibra lion curves were linear expression from 21$\mu $g/ml to 101$\mu $g/ml. As the results of analysis, the residual propionic acid was not detected in the 100 samples of honey. Retention time(min) of OTC, DC, and TC were 3.35, 4.61, and 5.30 minutes at the conditions of table 2, respectively, and retention time(min) of propionic acid was 3.50 minutes at the conditions of table 3. The residual TCs and propionic acid were not detected in the 100 samples of honey, but there is a possibility that antibiotics or propionic acid will be to remain in honey if they are used during product period in order to prevent putrefaction of honey-bee.

• The Korean Journal of Physiology and Pharmacology
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• 제14권3호
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• pp.185-189
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• 2010

The present study demonstrates the effect of fibrates, agonists of $PPAR{\alpha}$ on cytokines-induced proliferation in primary cultured astrocytes. Alone or combination treatment with cytokines, such as IL-$1{\beta}$ (10 ng/ml), $IFNP{\gamma}$ (10 ng/ml), and TNF-$\alpha$ (10 ng/ml) cause a significant increase of cell proliferation in a time-dependent manner. Treatment of astrocytes with bezafibrate and fenofibrate (0, 5, and $10\;{\mu}M$) reduced the $IFNP{\gamma}$ and IL-$1{\beta}$-induced cell proliferation in a dose-dependent manner. To address the involvement of IL-6 on the $IFNP{\gamma}$ and IL-$1{\beta}$-induced cell proliferation, released IL-6 level was measured. $IFNP{\gamma}$ and IL-$1{\beta}$ cause an increase of released IL-6 protein level in a time-dependent manner. Furthermore, pretreatment with IL-6 antibody (0, 0.1, 1, 2.5, and 5 ng/ml) dose-dependently inhibited the $IFNP{\gamma}$ and IL-$1{\beta}$-induced cell proliferation. However, bezafibrate and fenofibrate did not affect increased mRNA and protein levels of IL-6 in $IFNP{\gamma}$ and IL-$1{\beta}$-stimulated astrocytes. Taken together, these results clearly suggest that activation of $PPAR{\alpha}$ attenuates the $IFNP{\gamma}$ and IL-$1{\beta}$-induced cell proliferation through IL-6 independent pathway.

• Asian-Australasian Journal of Animal Sciences
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• 제14권2호
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• pp.189-192
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• 2001

This study was initiated in an effort to determine the normal mean and variations of the somatic cell count (SCC) in milk of buffaloes as influenced by the milking time, stage of lactation, parity and season. The buffaloes were hand milked at 13 and 11 h. interval during evening and morning respectively. On the day of milk sampling the udders were tested for mastitis by California Mastitis Test (CMT). Only those buffaloes, which were found negative in the CMT, were included in the sampling plan. The mean values for morning and evening were 1.09 (range 0.39-1.76) and $0.97(range\;0.57-2.46){\times}10^5cells/ml$, respectively which did not differ significantly. When data of the morning and evening values was compared on the basis of total cell secretion in milk, even then there was no statistical difference between the morning and the evening values, thereby suggesting that no diurnal variation existed in SCC of milk. Paritywise differences were not significant between the 1st to 5th lactation and above. Similarly stage of lactation effect, when tested at 30 day intervals, did not differ significantly. Significant (p<0.05) correlation coefficients (r) between SCC and milk yield during different stages of lactation and parity suggested that SCC per ml of milk was higher during the later stages of lactation. SCC was higher in primiparous than in multiparous buffaloes. On an average the SCC recorded was $1.0{\times}10^5cells/ml$ of milk irrespective of time of milking, parity and stages of lactation. The SCC was low during cold and hot-dry season but were high during the hot-humid season (p<0.05), the respective values being 0.76, 1.08 and $1.35{\times}10^5cells/ml$. These values were lower than the SCC already reported in cows suggesting less stressful condition of the udder of buffaloes in this study.

• 한국항행학회논문지
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• 제15권2호
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• pp.298-306
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• 2011

본 논문은 팩시밀리를 위한 이진 영상 압축 표준인 JBIG2의 주요 구성모듈의 하나인 심벌 ID 코드 길이 부호화를 위한 런코드 부호기 IP를 하드웨어로 설계구현에 관한 것이다. VHDL코드 생성 및 하드웨어 합성을 위해서 ImpulseC Codeveloper와 Xilinx ISE/EDK 프로그램을 사용하였다. 합성된 하드웨어는 Xilinx사의 ML410 개발보드의 Virtex-4 FX60 FPGA에 다운로드하여 성능평가를 수행하였다. 합성된 하드웨어가 FPGA에서 차지하는 면적은 전체 slice의 13%를 차지하였다. 동작 검증을 위해 Active HDL 툴을 이용하여 각 IP에 대한 파형 검증을 수행한 결과 정상 동작함을 확인함으로써 하드웨어로의 구현에 적합성을 확인하였다. 아울러 ML410 개발보드 상에서 Microblaze CPU를 이용해 소프트웨어로만 수행한 경우와 동작 속도를 비교 한 결과, 구현된 하드웨어는 40배 이상의 빠른 처리 속도를 나타내었다. 구현된 하드웨어와 연동된 소프트웨어 모듈로 표준 CCITT문서를 압축한 결과 정상적으로 동작함을 확인하였다.

• 한국가축번식학회지
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• 제14권3호
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• pp.213-221
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• 1990

This study was conducted to find out the changes of progesterone and estrone sulphate concentration in serum of Korean native goats throughout gestation, and to apply the serum levels of the hormones to pregnancy diagnosis. Serum concentration of progesterone and estrone sulphate were assayed by radioimmunoassay. Serum progesterone concentration was similar to its luteal phase values during early pregnancy and remained at the high level continually at 20∼140days and decreased rapidly at the day of parturition. Serum estrone sulphate concentration showed to increase markedly at 40∼50dyas gestation and steadily increased to the maximum of 7.13ng/ml at 140days, but declined sharply at the day of parturition. The accuracy of pregnancy diagnosis by the measurement of serum progesterone at 20∼24days after mating was 85.7∼92.3% and that of non-pregnancy diagnosis was 100%, when the serum progesterone levels higher and lower than 3.0ng/ml were supposed to indicate pregnancy and non-pregnancy, respectively. The accuracy of pregnancy diagnosis by the mearsurement of serum estrone sulphate was found to be nearly 100% since 50days after mating, when the serum levels of estrone sulphate higher then 0.5ng/ml were diagnosed to be pregnant. The optimal sampling time for pregnancy diagnosis was considered to be at 50 days after mating or to be later. It appears that estrone sulphate values above 7.0ng/ml at any time in gestation are highly indicative of twin. But there was found no significant difference(P<0.05) in serum estrone sulphate concentration and number of kids between does with single and twin kids.

• Korean Chemical Engineering Research
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• 제49권4호
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• pp.470-474
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• 2011

볏짚은 한국에서 매년 대량 생산되는 주요 작물이다. 침지공정을 이용한 목질계 바이오매스의 전처리는 대기압과 $60^{\circ}C$의 온도에서 온화한 조건에서 수행되었다. 본 연구에서는 전처리된 바이오매스의 효소당화 조건을 찾아보았다. 볏짚의 경우에 이전의 목질계 바이오매스와 비교하여 당화시간이 다른 것들보다 짧은 것으로 나타났다. SAA(Soaking in Aqueous Ammonia) 전처리 볏짚의 당화는 40~48시간 사이에 종료가 되었고 $50^{\circ}C$에서 높은 글루코스 전환율을 나타냈다. 글루코스 전환율은 효소사용량이 각각 65 FPU/ml과 32 CbU/ml일 때 높았다. 기질 농도가 5%(w/v)일 때 전환율은 72시간 동안 당화 후에 83.8%로 나타났다. SAA 전처리 볏짚의 동시당화발효(SSF; Simultaneous Saccharification and Fermentation) 실험에서는 $40^{\circ}C$에서 높은 에탄올 생산수율을 보였다. 그때의 수율은 48시간에서 33.05%로 나타났다.

• Journal of Pharmaceutical Investigation
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• 제26권4호
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• pp.299-308
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• 1996

In order to develop the controlled release of a drug from the suppsitories, in vitro drug release and in vivo absorption in rabbits were investigated. Various suppository forms with hollow cavities, into which drugs in the form of fine powder or solid dispersion system(SDS) could be placed, were utilized. The polyvinyl alcohol(PVA) hydrogel as a base, and propranolol HCl(PPH) as a model drug were employed. In vitro drug dissolution studies showed that the dissolved amounts(%) of PPH from PPH-methylcellulose(MC)-SDS and PPH-ethylcellulose(EC)-SDS reached 100% and 63% in 4.5-hours, respectively. In the relative strength test for PVA hydrogel, PVA hydrogel became harder and more rigid when the number of freezing-thawing cycles and the ratio of PVA 2000 were increased. In vitro drug release profile revealed that the release rate(%) of PPH from PPH-EC-SDS and PPH-MC-SDS hollow type suppositories were sustained. The release amount(%) of PPH from PPH-EC-SDS hollow type suppositories was not affected by storage time, but since the use of hydrophilic MC made PPH diffuse into the hydrogel after it absorbed the water of base, the various release patterns were appeared as the storage time went by. In vivo absorption experiments with rabbits showed that PPH-EC-SDS(PPH : EC=1:3) hollow type suppository delayed the absorption of PPH, significantly. The $C_{max}$, $AUC_{0{\rightarrow}8}$ and MRT of PPH powder hollow type suppository were $196.37{\pm}5.63\;ng/ml$, 1105.26 ng/ml/min and 8.66 min, respectively. The $C_{max}$, $AUC_{0{\rightarrow}8}$ and MRT of PPH-EC-SDS(PPH : EC=1:3) were $91.30{\pm]14.14\;ng/ml$, 554.69 ng/ml/min, 235.99 min, respectively.