• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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• pp.40-45
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• 2001

Raw starch-digesting amylase (BF-2A, M.W. 93, 000 Da) from Bacillus circulans F-2 was converted to two components during digestion with subtilisin. Two components were separated and designated as BF-2A' (63, 000 Da) and BF-2B (30, 000 Da), respectively. BF-2A' exhibited the same hydrolysis curve for soluble starch as the original amylase (BF-2A). Moreover, the catalytic activities of original and modified enzymes were indistinguishable in $K_{m}$, Vmax for, and in their specific activity for soluble starch hydrolysis. However, its adsorbability and digestibility on raw starch was greatly decreased. Furthermore, the enzymatic action pattern on soluble starch was greatly different from that of the BF-2A. A smaller peptide (BF-2B) showed adsorb ability onto raw starch. By these results, it is suggested that the larger peptide (BF-2A') has a region responsible for the expression of the enzyme activity to hydrolyze soluble substrate, and the smaller peptide (BF-2B) plays a role on raw starch adsorption. A similar phenomenon is observed during limited proteinase K, thermolysin, and endopeptidase Glu-C proteolysis of the enzyme. Fragments resulting from proteolysis were characterized by immunoblotting with anti-RSDA. The proteolytic patterns resulting from proteinase K and subtilisin were the same, producing 63- and 30-kDa fragments. Similar patterns were obtained with endopeptidase Glu-C or thermolysin. All proteolytic digests contained a common, major 63-kDa fragment. Inactivation of RSDA activity results from splitting off the C-terminal domain. Hence, it seems probable that the protease sensitive locus is in a hinge region susceptible to cleavage. Extracellular enzymes immunoreactive toward anti-RSDA were detected through whole bacterial cultivation. Proteins of sizes 93-, 75-, 63-, 55-, 38-, and 31-kDa were immunologically identical to RSDA. Of these, the 75-kDa and 63-kDa proteins correspond to the major products of proteolysis with Glu-C and thermolysin. These results postulated that enzyme heterogeneity of the raw starch-hydrolysis system might arise from the endogeneous proteolytic activity of the bacterium. Truncated forms of rsda, in which the gene sequence encoding the conserved domain had been deleted, directed the synthesis of a functional amylase that did not bind to raw starch. This indicates that the conserved region of RSDA constitutes a raw starch-binding domain, which is distinct from the active centre. The possible role of this substrate-binding region is discussed.d.

• 생명과학회지
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• 제29권7호
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• pp.779-784
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• 2019

도라지의 탈모예방 효과를 검증하기 위해 몇가지 용매를 이용하여 도라지 분획물을 준비하였다. 산화적 스트레스는 두피혈관을 좁게 하여 모근으로의 영양공급을 방해함으로써 탈모를 유발한다. 본 연구에 사용된 분획물인 BF와 WF는 DPPH 라디칼 소거능의 $IC_{50}$값이 각각 16.2 mg/ml와 121.8 mg/ml로, 모두 농도의존적으로 소거능이 증가하는 것으로 나타났다. 또한 ABTS 라디칼 소거능 실험결과에서도 BF와 WF 처리시 $IC_{50}$값이 각각 4.9 mg/ml와 39.8 mg/ml로 높은 항산화활성을 나타내었다. 또한 인간피부세포인 HaCaT cell 증식 실험결과, 24시간 BF와 WF 처리 시 각각 최대 31%($1{\mu}g/ml$)와 18%($1{\mu}g/ml$)로 HaCaT cell 증식을 촉진시키는 것으로 나타나 추출물이 피부재생효과가 있음을 증명하였다. 탈모의 원인중의 하나인 두피의 염증에 대한 분획물의 효능을 확인하고자, RAW264.7 cell을 이용하여 염증반응 생성물인 NO와 $PGE_2$ 생성정도를 관찰하였다. 그 결과, BF와 WF 각각 최대 88.5%($0.1{\mu}g/ml$)와 88.0%($50{\mu}g/ml$)까지 NO와 $PGE_2$ 생성을 저해하는 것으로 나타났다. 모낭을 구성하는 모유두세포인 HFDPC cell 증식 실험 결과, 4, 48, 72시간 처리 시 모두 HFDPC cell 증식을 농도의존적으로 증가시키는 것으로 나타났다. 이상의 결과를 토대로 본 연구에 사용된 도라지로부터 추출한 부탄올 분획물과 물 분획물이 탈모예방에 효과적이며, 그중에서도 특히 부탄올 분획물이 탈모예방제품의 유용한 천연재료로써의 가치가 있음을 증명하였다.

• 멤브레인
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• 제27권4호
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• pp.313-318
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• 2017

올레핀/파라핀 분리를 위해 $Poly(ethylene oxide)(PEO)/AgBF_4/Al(NO_3)_3/Ag_2O$ 복합막이 제조되었으며, $Ag_2O$가 도입되었을 때, 복합체 분리막의 초기성능은 선택도 13.7과 투과도 21.7 GPU로 관찰되었다. $PEO/AgBF_4/Al(NO_3)_3$ 분리막의 성능(선택도 13와 투과도 7.5 GPU)에 비해서 초기성능이 증가한 이유는 $Ag_2O$의 첨가로 인한 Ag ion의 활성도 증가로 생각되었다. 하지만 시간에 따른 성능저하 현상이 관찰되었는데 이는 고분자 matrix인 PEO 때문인 것으로 생각되었다. PEO 고분자는 $Ag_2O$ 입자를 안정화 시킬 수 없기 때문에 용매가 증발하면서 $Ag_2O$ 입자끼리 뭉치게 되고, $Ag_2O$가 barrier 역할을 하게 돼서 시간이 지나면 투과도가 감소하는 것으로 분석되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권2호
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• pp.180-187
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• 2015

This study was conducted to determine the effects of feeding by-product feed (BF)-based silage on the performance, blood metabolite parameters, and carcass characteristics of Hanwoo steers. The BF-based silage was composed of 50% spent mushroom substrate, 21% recycled poultry bedding, 15% cut ryegrass straw, 10.8% rice bran, 2% molasses, 0.6% bentonite, and 0.6% microbial additive (on a wet basis), and ensiled for over 5 d. Fifteen steers were allocated to three diets during the growing and fattening periods (3.1 and 9.8 months, respectively): a control diet (concentrate mix and free access to rice straw), a 50% BF-based silage diet (control diet+50% of maximum BF-based silage intake), and a 100% BF-based silage diet (the same amount of concentrate mix and ad libitum BF-based silage). The BF-based silage was fed during the growing and fattening periods, and was replaced with larger particles of rice straw during the finishing period. After 19.6 months of the whole period all the steers were slaughtered. Compared with feeding rice straw, feeding BF-based silage tended (p = 0.10) to increase the average daily gain (27%) and feed efficiency (18%) of the growing steers, caused by increased voluntary feed intake. Feeding BF-based silage had little effect on serum constituents, electrolytes, enzymes, or the blood cell profiles of fattening steers, except for low serum Ca and high blood urea concentrations (p<0.05). Feeding BF-based silage did not affect cold carcass weight, yield traits such as back fat thickness, longissimus muscle area, yield index or yield grade, or quality traits such as meat color, fat color, texture, maturity, marbling score, or quality grade. However, it improved good quality grade (1+ and 1++) appearance rates (60% for the control group vs 100% for the BF-based silage-fed groups). In conclusion, cheap BF-based silage could be successfully used as a good quality roughage source for beef cattle.

• 대한화학회지
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• 제38권11호
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• pp.833-840
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• 1994

8-Quinolinecarboxaldehyde (1)와 1,5-hexadiene (2)을 월킨슨 촉매(3)와 $AgBF_4(8)$의 혼합 촉매에서 반응시키면 8-quinolinyl 5-hexenyl ketone(4)와 8-quinolinyl 5-hexen-2-yl ketone (9)이 높은 수율로 반응초기에 생성된다. 가지달린 alkenyl 케톤인 9가 생성되는 이유는 월킨슨 촉매와 $AgBF_4(8)$의 반응에서 촉매에 빈 배위공간이 만들어져 1,5-hexadiene의 하이드로메탈레이션반응에서 $AgBF_4(8)$를 넣지 않았을 때보다는 입체장애가 적은 5.5각형의 중간체를 만들 수 있기 때문으로 설명된다. $AgBF_4(8)$의 사용량이 많으면 많을수록 9가 4보다 많은 비율로 생성되며, 장시간과 고온에서는 생성된 9와 4의 혼합물이 10과 5의 내부올레핀을 함유한 alkenyl 케톤으로 이성질화반응이 진행됨을 관찰할 수 있었다. 특히 고온으로 반응을 진행시킬수록 8-quinolinyl cyclopentylmethyl ketone (11)의 생성이 눈에 띄게 높아짐을 알 수 있었다.

• Nutritional Sciences
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• 제8권1호
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• pp.50-55
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• 2005

This study was conducted to determine the relationship between the body fat percent (BF%) and body mass index (BMI) of Koreans and the differences with Caucasians. Complete data were collected from 3297 subjects (2441females and 856 males) between the ages of 18 and 79. Data were collected between September 2001 and November 2001 in Seoul and Pusan. For the statistical analysis, only the data on subjects between the ages of 18 and 65(3200) were used Body weight and height were measured BMI (kg/$m^2$) was computed From BMI, BF (%) was calculated using age- and sex-specific prediction formulas. BF% was assessed using an INBODY 2.0 body fat analyser. Data analysis showed that the females were significantly younger than the males, were smaller, lighter and had a lower body mass index. Body fat percent of the females was higher than that of the males. 1he differences between actual measured BF% and BF% as predicted from prediction equations from the literature, based on BMI, age and sex, were correlated with level of body fat and age. There is a significant age-related decrease in body fat in Koreans for any given BMI and sex, which is remarkably different compared to age-related increases in body fat in the European reference group. For the same age and BF%, Korean females have a slightly lower BMI than their European counterparts. Korean males have, for the same age and BF%, a higher BMI than their European counterparts. The differences between females and males were not significant. It was concluded that, assuming that the data on body fat percent was correct, that the relationship between BF% and BMI is quite different in Koreans than in European Caucasians. Thus, for younger Koreans cut-off values for obesity should be slightly lower than those for Caucasians whereas for older Koreans the cut-off points for obesity should be higher than those for Caucasians.

• 대한치과교정학회지
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• 제52권3호
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• pp.172-181
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• 2022

Objective: The objectives of this study were to compare the time-dependent changes in occlusal contact area (OCA) and bite force (BF) of the deviated and non-deviated sides in mandibular prognathic patients with mandibular asymmetry before and after orthognathic surgery and investigate the factors associated with the changes in OCA and BF on each side. Methods: The sample consisted of 67 patients (33 men and 34 women; age range 15-36 years) with facial asymmetry who underwent 2-jaw orthognathic surgery. OCA and BF were taken before presurgical orthodontic treatment, within 1 month before surgery, and 1 month, 3 months, 6 months, 1 year, and 2 years after surgery. OCA and BF were measured using the Dental Prescale System. Results: The OCA and BF decreased gradually before surgery and increased after surgery on both sides. The OCA and BF were significantly greater on the deviated side than on the non-deviated side before surgery, and there was no difference after surgery. According to the linear mixed-effect model, only the changes in the mandibular plane angle had a significant effect on BF (p < 0.05). Conclusions: There was a difference in the amount of the OCA and BF between the deviated and non-deviated sides before surgery. The change in mandibular plane angle affects the change, especially on the non-deviated side, during the observation period.

• 한국물환경학회지
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• 제26권5호
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• pp.732-739
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• 2010

Two combined autothermal thermophilic aerobic digestion (ATAD) and biofilter (BF) systems were operated to treat the piggery wastewater and the ammonia offgas. Experimental results indicated that the organic removal efficiency of ATAD-2, operated with oxygen, was higher than that of ATAD-1, operated with air. The concentration of ammonia in ATAD-2 offgas was higher compared to ATAD-1 offgas, but the total amount of ammonia produced from ATAD-2 was less than that from ATAD-1 due to the lower oxygen flowrate. The ammonia gas produced from both ATAD reactors was successfully removed by the BF. The BF-1, connected with ATAD-1, removed 93% of ammonia at the loading rate of $9.4g\;NH_3-N/m^3/hr$. The BF-2, connected with ATAD-2, removed 95% of ammonia gas at the loading rate of $8.1g\;NH_3-N/m^3/hr$. As the nitrification process continued, pH value of recirculating solution continuously decreased due to the accumulation of nitrate. When the ammonia loading rate was less than $22.7g\;NH_3-N/m^3/h$, the proper replacing cycle of recirculating solution was in the range of 10 to 11 days. Almost 90% of total mass of nitrogen fed into the each BF was confirmed from the mass balance on nitrogen.

• Bulletin of the Korean Chemical Society
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• 제8권3호
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• pp.140-144
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• 1987

The effect of Lewis acids on spectroscopic properties and photodimerization of coumarin and 5,7-dimethoxycoumarin was investigated. Quantum yields of coumarin photodimerization increase in the presence of $BF_3{\cdot}OEt_2$ but those of 5,7-dimethoxycoumarin decrease. The spectroscopic properties of the coumarin-$BF_3{\cdot}OEt_2$ and 5,7-dimethoxycoumarin-$BF_3{\cdot}OEt_2$ complexes were studied by UV, IR, $^1H$ NMR and fluorescence spectroscopy.

• 대한전자공학회논문지
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• 제25권3호
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• pp.294-301
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• 1988

A study on the lattice damages and impurity depth profiles have been performed with BF2 ion implanted silicon materials. Electrical measurement, SIMS and TEM analysis techniques were used in order to identify the reverse annealing phenomena, impurity depth profiles and lattice damages. A typical reverse annealing phenomena were shown at the dose of 1x10**15/cm\ulcorner and non-reverse annealing at the dose of 5x10**15/cm\ulcorner This was explained with the formation of the amorphous region at BF2+ ion implantation with high dose. That is, the amorphous reigons were recrystallized centrated at certain regions were measured by SIMS technique. The dislocation loops-like crystalline defects were observed with TEM cross sections, which were formed at the lattice damaged region during annealing process.