• Asian-Australasian Journal of Animal Sciences
• /
• 제18권10호
• /
• pp.1435-1439
• /
• 2005

Bacterio-mineral water (BMW) produced from manure has been known to exert a number of positive effects on animal production and odor control. An experiment was conducted to examine the effects of BMW produced from bio-reacted swine manure on in vitro gas production, cellulose degradation, microbial growth and fibrolytic enzyme activities of mixed rumen microorganisms. The five levels of 0, 0.001, 0.005, 0.01 and 1.0% BMW were supplemented into serum vials containing mixed rumen microorganisms. Incubations were carried out anaerobically at $39^{\circ}C$ without shaking for 0, 12, 24, 48, 72 and 96 h. There were no significant (p>0.05) differences among the treatments for the initial rate of gas production. At 72 h incubation, the gas production tended (p<0.1) to be increased by the 0.01 and 1.0% BMW treatments compared with control and the 0.001% BMW treatment. At the end of incubation (96 h), the sample supplemented with 0.01% BMW was higher (p<0.05) than control (0% BMW) in the gas production. The microbial growth rate was increased by all the BMW treatments, while 0.01% BMW was most effective in stimulating the growth rate. Although the addition of BMW on the filter paper DM degradation was not significantly influenced throughout the incubation period except the 48 h incubation, DM degradation tended to be increased by all BMW treatments compared with control. The addition of both 0.005 and 0.01% BMW highly increased (p<0.05) CMCase activity compared with control after 24 h and 48 h incubation, while at the 72 h incubation the 0.01% BMW addition only significantly increased (p<0.05). After 72 h incubation, the xylanase activity was significantly (p<0.05) increased with the addition of 1.0% BMW compared with the addition of 0.001 and 0.005% BMW, while at the other incubation times, the xylanase activity was not different among the treatments. In conclusion, the 0.01% BMW of supplementation level would be the suitable addition level to stimulate rumen fermentation increasing microbial growth and cellulose degradation.

• 유기물자원화
• /
• 제26권2호
• /
• pp.65-73
• /
• 2018

본 연구는 음식물쓰레기의 발효건조를 위한 최적 운전조건을 도출하기 위하여 0.75, 1.00, 1.25, $1.50L/min{\cdot}kg$의 송풍조건에서 발효건조 회분식 반응기를 20일간 운전하였으며, Modified Gompertz 모델을 이용하여 발효건조 기간 중 반응기내에서의 유기물 분해반응속도를 분석하였다. 유기물 분해 반응속도 분석에서 최대 유기물 분해량 (P)은 송풍량 0.75, 1.00, 1.25, $1.50L/min{\cdot}kg$에서 각각 2.31, 2.52, 2.27, 1.88 kg이었으며, 최대 유기물 분해속도 ($R_m$)는 송풍량 0.75, 1.00, 1.25, $1.50L/min{\cdot}kg$에서 각각 0.33, 0.45, 0.28, 0.18 kg/day를 보여 송풍량 $1.00L/min{\cdot}kg$에서 우수한 유기물 분해효율을 보였다. 발효건조 반응기의 지체성장시간 (${\lambda}$)은 송풍량 0.75, 1.00, 1.25, $1.50L/min{\cdot}kg$에서 각각 2.10, 1.48, 1.15, 1.06 일로 나타나 $0.75L/min{\cdot}kg$의 적은 송풍조건에서 가장 긴 지체성장시간을 보여 송풍량의 증가는 지체성장시간을 단축시키는 것으로 나타났다. 음식물쓰레기 발효건조 반응기의 운전에서 수분 제거율은 발효건조 반응기 운전 초기에서 중기로 갈수록 송풍량 증가와 함께 증가하다가 발효건조 반응기 운전 말기에는 송풍량 $1.00L/min{\cdot}kg$에서 가장 높은 수분 제거율을 보여 발효건조의 최적 송풍조건은 $1.00L/min{\cdot}kg$으로 나타났다.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
• /
• pp.200.3-200.3
• /
• 2003

Reactive oxygen species(ROS) are produced at a high rate continuously as a by-product of aerobic metabolism. Several lines of evidence provided that ROS appears to cause to develop aging and various diseases. High level of hyaluronic acid with decreased molecular weight has been detected in patients with inflammatory diseases including rheumatoid arthritis. Hyaluronidase is an endohexosaminidase that initiates the degradation of hyaluronic acid with high molecular weight. Prunus persica Batsch var. davidiana Maximowicz has been known as a korean folk medicine for treatment of neuritis and rheumatism. (omitted)

• 한국전기전자재료학회논문지
• /
• 제34권6호
• /
• pp.487-494
• /
• 2021

Piezoelectric generators use direct piezoelectric effects that convert mechanical energy into electrical energy. Many studies were attempted to fabricate piezoelectric generators using piezoelectrics such as ZnO, PZT, PVDF. However, these various inorganic/organic piezoelectric materials are not suitable for bio-implantable devices due to problems such as brittleness, toxicity, bio-incompatibility, bio-degradation. Thus, in this paper, piezoelectric generators were prepared using a silk fibroin film which is bio-compatible by dip-coating method. The silk fibroin films are a mixed state of silk I and silk II having stable β-sheet type structures and shows the d₃₃ value of 8~10 pC/N. There was a difference in output voltages according to the thickness. The silk fibroin generators, coated 10 times and 20 times, revealed the power density of 16.07 μW/cm² and 35.31 μW/cm² using pushing tester, respectively. The silk fibroin generators are sensitive to various pressure levels, which may arise from body motions such as finger tapping, foot pressing, wrist shaking, etc. The silk fibroin piezoelectric generators with bio-compatibility shows the applicability as a low-power implantable piezoelectric generator, healthcare monitoring service, and biotherapy devices.

• Journal of the Korean Wood Science and Technology
• /
• 제33권1호통권129호
• /
• pp.29-37
• /
• 2005

본 연구는 바이오복합재(bio-composites) 제조시 제조온도와 시간이 기질인 열가소성 고분자와 충전제인 왕겨분말에 미치는 영향을 평가하기 위하여 수행하였다. 제조온도가 왕겨분말에 미치는 영향에 대해 알아보기 위해 왕겨분말을 $220^{\circ}C$에서 10분부터 2시간 동안 처리한 후 열가소성 고분자인 polypropylene (PP)과 low-density polyethylene (LDPE)에 충전제로 첨가하여 바이오복합재를 제조한 후 기계적 성질을 측정하였다. $220^{\circ}C$에서 왕겨분말의 처리시간이 증가할수록 왕겨분말의 주요 구성성분이 열분해로 인하여 인장강도와 충격강도값이 감소하였다. 실제적인 제조온도에 의한 중량감소를 측정하기 위하여 열중량분석기(thermogravimetric analysis, TGA)를 이용하여 $220^{\circ}C$의 등온상태에서 2시간 동안 측정한 결과 열가소성고분자에서는 중량의 변화가 거의 발생하지 않았으며 충전제인 왕겨분말과 바이오복합재의 경우 시간이 증가할수록 열분해에 의한 중량감소량이 증가하는 것을 확인할 수 있었다. 그러므로 바이오복합재 제조시 높은 제조온도로 인한 물성의 저하를 방지하기 위해서는 적절한 온도와 제조시간을 결정하는 것이 중요하다고 볼 수 있다.

• 폴리머
• /
• 제29권6호
• /
• pp.599-604
• /
• 2005

생체적합성이 우수한 히아루론산과 생분해성이 우수한 폴리락타이드의 이량체인 락타이드를 결합하여 인체내에서 분해속도를 조절할 수 있는 생체적합성이 우수한 생체재료를 제조하였다. 냉동 건조법을 이용하여 히아루론산과 락타이드를 가교제 1-ethyl-3-(3-dimethyl aminopnpyl) carbodiimide(EDC)로 가교시켰다. 생성된 막을 핵자기 공명분광법으로 분석하여 젖산기 반응도와 EDC 반응도를 결정하였다. 히아루론산에 대한 락타이드의 몰비가 5부터 13까지 증가함에 따라 젖산기 반응도와 EDC 반응도는 증가하였다. 몰비가 커서 젖산기가 많이 첨가되면 팽윤도는 감소하고 취성이 강해졌다. 또 가교제 농도를 증가시키거나 가교 온도를 감소시키면 젖산기가 더욱 첨가되어 팽윤도는 감소하고 탄성률은 증가하였다. 서로 다른 가교도를 가진 막에 대해 약물 방출 실험을 한 결과 막의 가교도가 증가함에 따라 약물의 투과도는 감소하였다. 몰비가 커 젖산기가 많이 첨가된 고분자일수록 늦게 분해되었다. 몰비, 온도, 가교제 농도 등의 운전 변수를 조절하여 막의 기계적 물성과 분해 속도가 적절히 조절될 수 있었다.

• 한국산학기술학회논문지
• /
• 제16권9호
• /
• pp.6403-6410
• /
• 2015

의료용 고분자 PLGA는 높은 생체적합성, 생분해성, 기계적 특성, 생체안정성을 가지고 있으며, 단량체 수량을 조절함으로서 분해기간을 조절할 수 있는 장점이 있다. 본 논문에서는 상전이법을 이용하여 제조된 분자량과 L/D 타입 구성비가 다른 PLGA 멤브레인들을 인산완충생리식염수 하에서 멤브레인의 분자량과 용액의 온도 조건에 따른 생분해 특성을 유추하기 위하여 질량 변화와 용액의 pH값 측정하였으며, DSC와 실사현미경을 이용하여 Tg와 표면구조의 변화을 파악하였다. PLGA의 분자량이 증가할수록 가수분해속도는 기하급수적으로 감소하고 있으며, L/D 타입 구성비에 따라 분해속도와 용액 pH변화의 차이가 크게 나타났다.

• 환경위생공학
• /
• 제18권1호
• /
• pp.23-29
• /
• 2003

The effect of ozone oxidation on bio-degradability of leachate was studied. Ozone oxidation process was used as pre-treatment process to enhance performance of biological process in treating landfill leachate. Optimum ozone injection rate and contact time in this experiment was $160{\;}mg{\;}O_/{\ell}{\cdot}hr$ and 45 minutes, respectively. Bio-degradability was enhanced 5.08% by ozone oxidation. The ratio of ozone demand/DOC concentration was $0.049~0.091{\;}mg{\;}O_3/mg{\;}DOC$. The increase of bio-degradability depending on ozone injection rate(D) and contact time(T) can be expressed as follows ; The rate of bio-degradation of DOC was increased proportionally with the increase of ozone injection rate and contact time irrespective of landfill site age. The increase of bio-degradability by ozone addition was not satisfactory. It is hard to expect significant increase in bio-degradability by ozone treatment only. Thus, it is evaluated that ozone oxidation can not increase biodegradability significantly in concentrated wastewater composed of complex organic compound such as leachate.

• 한국결정학회:학술대회논문집
• /
• 한국결정학회 2003년도 춘계학술연구발표회
• /
• pp.15-15
• /
• 2003

To discover new drugs more quickly and more efficiently, pharmaceutical companies and biotechnology firms are increasingly turning to the genomics and the structural proteomics technologies. Structural-proteomics can provide a foundation for this through the determination and analysis for protein structure on a genomics scale. Among many structures determined by CGI, we will present with the representative examples drawn from our work on novel structures or complex structures of the disease-related proteins. The alpha subunit of Hypoxia-inducible factor (HIF) is targeted for degradation under normoxic conditions by an ubiquitin-ligase complex that recognizes a hydroxylated proline residue in HIF. Hydroxylation is catalysed by HIF prolyl 4-hydroxylases (HIFPH) which are fe(II) and 2-oxoglutarate (2-OG) dependent oxygenases. Here, we discuss the first crystal structure of the catalytic domain of HIFPH in complexes, with the Fe(II)/2-OG at 1.8Å. These structures suggest that the Ll region (residues 236-253), which is also conserved in mammals, form a 'lid' that closes over the active site. The structural and mutagenesis analyses allow us to provide a focus for understanding cellular responses to hypoxia and a target for the therapeutic manipulation.

• 한국생물물리학회:학술대회논문집
• /
• 한국생물물리학회 2003년도 정기총회 및 학술발표회
• /
• pp.28-28
• /
• 2003

To discover new drugs more quickly and more efficiently, pharmaceutical companies and biotechnology firms are increasingly turning to the genomics and the structural proteomics technologies. Structural-proteomics can provide a foundation for this through the determination and analysis for protein structure on a genomics scale. Among many structures determined by CGI, we will present with the representative examples drawn from our work on novel structures or complex structures of the disease-related proteins. The alpha subunit of Hypoxia-inducible factor (HIF) is targeted for degradation under normoxic conditions by an ubiquitin-ligase complex that recognizes a hydroxylated proline residue in HIF, Hydroxylation is catalysed by HIF prolyl 4-hydroxylases (HIFPH) which are Fe(II) and 2-oxoglutarate (2-OG) dependent oxygenases. Here, we discuss the first crystal structure of the catalytic domain of HIFPH in complexes, with the Fe(II)/2-OG at 1.8 ${\AA}$. These structures suggest that the L1 region (residues 236-253), which is also conserved in mammals, form a ‘lid’ that closes over the active site. The structural and mutagenesis analyses allow us to provide a focus for understanding cellular responses to hypoxia and a target for the therapeutic manipulation.