• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1267-1274
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• 2004

Colostrum contains various kinds of cytokines including TGF-$\beta$ that has potent regulatory effects on cells of the immune system. We compared the levels of TGF-$\beta$1 and TGF-$\beta$2 in bovine and human colostrum. Based on the isoform-specific ELISA, bovine colostrum collected on day 1 post-delivery retained $53.71{\pm}29.55\;ng/ml$ of TGF-$\beta$1 and $40.41{\pm}21.78\;{\mu}g/ml$ of TGF-$\beta$2 (n=4), while in human, $381.45{\pm}158.24\;ng/ml$ of TGF-$\beta$1 and $41.47{\pm}9.63\;ng/ml$ of TGF-$\beta$2 (n=5). Thus, dominant TGF-$\beta$ isoforms were completely opposite between human and bovine colostrum samples. The concentrations of both isoforms declined as lactation proceeded. Biological activities of the colostrum samples were determined using an MV1LU cell line. Consistent with the result from the immunoassay, TGF-$\beta$1 in human and TGF-$\beta$2 in bovine colostrum were responsible for the anti proliferative activity against MV1LU cells. Furthermore, bovine colostrum increased IgA secretion by LPS-stimulated mesenteric lymph node (MLN) cells, and this effect was abrogated by either anti­TGF-$\beta$2 antibody or combined anti-TGF-$\beta$1/$\beta$2 antibody, but not by anti- TGF-$\beta$1 antibody alone. Similarly, TGF-$\beta$2 in bovine colostrum enhanced the Ig germ line (GL) promoter activity, which is the earliest event toward IgA isotype switching. Taken together, these results suggest that TGF-$\beta$ isoforms, differentially expressed in human and bovine colostrum, may promote IgA isotype production in the neonatal intestine.

• 한국미생물·생명공학회지
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• 제20권6호
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• pp.693-698
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• 1992

공장 폐수를 비롯한 중금속 오염 환경으로부터 효율적인 중금속 제거를 위해 생물학적 오염제거에 관한 연구가 많이 이루어지고 있다. 본 실험에서는 항생제 내성 유전자를 많이 가지고 있는 것으로 알려진 Serratia marcescens를 대상으로 이 균주가 중금속들에 대해 어떤 영향을 보이는지 조사하였다. 그 결과 lead, iron, magnesium, manganese 등의 처리군에서 24시간내에 1,000ppm 이상의 고농도 처리군에서 최소억제성장농도(MIC)를 나타냈으며, cadmium에서는 600ppm 처리군에서, 구리는 800ppm의 처리군에서 MIC를 보였으며, 아연 처리군에서는 800ppm에서 MIC를 나타냈다. 또한 48시간 배양에 따른 MIC 비교 결과, 중금속의 고농도 처리군에서 매우 긴 적응기를 갖는 것으로 확인하였다. 15가지의 항생체를 대상으로 저항성을 조사한 결과, ampicillin, tetracycline, cefamandole, cephalothin에서 저항성을 보엿으며 다른 S. marcescens 균주들에 비해 chloramphenicol에 대한 특이한 민감성을 보였다. 카드뮴과 납을 대상으로 중금속의 세포내 흡수를 조사한 결과 16.59%와 35.38%의 중금속이 세포내로 흡수되었음을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1024-1032
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• 2008

Efficient expression of the Salmonella Typhimurium tdc ABCDEG operon involved in the degradation of L-serine and L-threonine requires TdcA, the transcriptional activator of the tdc operon. We found that the tdcA gene was transiently activated when the bacterial growth condition was changed from aerobic to anaerobic, but this was not observed if Salmonella was grown anaerobically from the beginning of the culture. Expression kinetics of six tdc genes after anaerobic shock demonstrated by a real-time PCR assay showed that the tdc CDEG genes were not induced in the tdcA mutant but tdcB maintained its inducibility by anaerobic shock even in the absence of tdcA, suggesting that an additional unknown transcriptional regulation may be working for the tdcB expression. We also investigated the effects of nucleoid-associated proteins by primer extension analysis and found that H-NS repressed tdcA under anaerobic shock conditions, and fis mutation delayed the peak expression time of the tdc operon. DNA microarray analysis of genes regulated by TdcA revealed that the genes involved in N-acetylmannosamine, maltose, and propanediol utilization were significantly induced in a tdcA mutant. These findings suggest that Tdc enzymes may playa pivotal role in energy metabolism under a sudden change of oxygen tension.

• 한국미생물·생명공학회지
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• 제14권6호
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• pp.455-460
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• 1986

간염 보균자의 혈액으로부터 Dane 입자를 분리하였다. Dane 입자의 핵으로부터 분리해낸 DNA는 $\alpha$-($^{32}$P) dNTP 존재하의 DNA 폴리머레이즈 반응 후 액체 씬틸레이션 카운터와 한천 전기영동 및 가이거 뮐러 카운터에 의하여 간염의 DNA임이 확인되었다. 간염 바이러스에 의한 감염을 막기 위한 백신으로서의 B형 간염 바이러스 표면항원을 생산하기 위하여 산성포스파테이즈 프로모터를 갖는 재조합 프라스미드를 함유하는 효모균주를 사용하였다. 재조합 프라스미드는 pHBV 130 및 pAM 82로부터 제작되었으며 대장균에 변환되어진 후 효모균주에 전달되었다. 간염 표면항원은 조절된 무기 인산 농도하에서 버크홀더 최소배지에서의 저해 해제로 생산되었다. 간염 표면항원의 생산 속도도 조사하였다. 전체 간염 표면항원 활성은 인산이 없는 배지에 옮겨진 뒤 3시간 내지 6시간에서 급격히 증가하였으며 9시간째에 최대에 도달하였다. 인산이 없는 배지에 옮기는 것은 고농도 인산 배지에서의 세포 배양을 6시간동안 수행한 뒤에 하는 것이 최적의 결과를 나타내었다.

• 한국물환경학회지
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• 제23권5호
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• pp.689-696
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• 2007

Kinetic analysis was important to develope the biological nutrient removal process effectively. In this research, anoxic-anaerobic-aerobic system was operated to investigate kinetic behavior on the nutrient removal reaction. Nitrification and denitrification were important microbiological reactions of nitrogen. The kinetics of organic removal and nitrification reaction have been investigated based on a Monod-type expression involving two growth limiting substrates : TKN for nitrification and COD for organic removal reaction. The kinetic constans and yield coefficients were evaluated for both these reactions. Experiments were conducted to determine the biological kinetic coefficients and the removal efficiencies of COD and TKN at five different MLSS concentrations of 5000, 4200, 3300, 2600, and 1900 mg/L for synthetic wastewater. Mathematical equations were presented to permit complete evaluation of the this system. Kinetic behaviors for the organic removal and nitrification reaction were examined by the determined kinetic coefficient and the assumed operation condition and the predicted model formulae using kinetic approach. The conclusions derived from this experimental research were as follows : 1. Biological kinetic coefficients were Y=0.563, $k_d=0.054(day^{-1})$, $K_S=49.16(mg/L)$, $k=2.045(day^{-1})$ for the removal of COD and $Y_N=0.024$, $k_{dN}=0.0063(day^{-1})$, $K_{SN}=3.21(mg/L)$, $k_N=31.4(day^{-1})$ for the removal of TKN respectively. 2. The predicted kinetic model formulae could determine the predicted concentration of the activated sludge and nitrifier, investigate the distribution rate of input carbon and nitrogen in relation to the solid retention time (SRT).

• KSBB Journal
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• 제32권2호
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• pp.117-123
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• 2017

Maple tree is a useful medical plant for obtaining bioactive materials such as pharmaceutics, cosmetics, food additive, etc., and there are 16 species of native maple trees in Korea. In this study, we evaluated the antioxidant activity of sap and crude extracts of Acer mono Max, a representative maple species. The crude extracts were obtained by solvent extraction (water, ethanol, and ethyl acetate) from its branches (bark and xylem). The phenolic contents and radical scavenging capacities of the extracts and the sap were evaluated in terms of half maximal effective concentration ($EC_{50}$) and kinetics by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The ethanol extracts showed the highest extraction yield, phenolic contents and antioxidant activity, and bark extracts showed better antioxidant activity than xylem extracts. The antioxidant activity of the sap was very low, but the $EC_{50}$ of ethanol and ethyl acetate extracts ranged from 68 to $79{\mu}g/mL$, similar to that ($60{\mu}g/mL$) of the control, butylated hydroxytoluene (BHT). The DPPH radical scavenging rate ($220{\sim}760{\mu}M/min$) and the second-order reaction rate constant ($6.48{\sim}7.04L/g{\cdot}min$) of these extracts were better than those of BHT ($55{\sim}370{\mu}M/min$ and $3.60L/g{\cdot}min$). These results suggest that A. mono Max. is one of the useful bioresources for obtaining antioxidant biologically active substances, and it is possible to obtain physiologically active substances from by-product of its pruning while minimizing the effect on the growth of the tree.

• Investigative Magnetic Resonance Imaging
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• 제19권3호
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• pp.137-145
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• 2015

Purpose: To investigate correlations of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor type 2 (HER2) statuses with magnetic resonance imaging (MRI) features and clinicohistological characteristics in patients with invasive lobular carcinoma (ILC). Materials and Methods: Data from 64 histologically confirmed ILCs were analyzed retrospectively. Preoperative breast MRI was reviewed for morphology and dynamic contrast-enhanced kinetics of the tumor. Pathologic reports were reviewed for ER, PR, and HER2 positivity, tumor size, lymph node metastasis, and the number of metastatic lymph nodes. Furthermore, there was an investigation of the MRI features and clinicohistologic characteristics, according to the ER, PR, and HER2 statuses. Results: A significant difference in MRI features and clinicohistological tumor characteristics were observed only in relation to PR status. Of the 64 ILCs, 10 (15.6%) were PR negative. PR negative cancers, compared with PR positive cancers, were more likely to present as non-mass enhancement (P = 0.027); have a significantly larger mean tumor size ($5.00{\pm}1.05cm$ vs. $2.57{\pm}0.21cm$, P = 0.021); and have significantly more metastatic lymph nodes (P = 0.010). Conclusion: PR negative ILC presented more frequently as non-mass enhancement on MRI, with larger tumors and increased numbers of metastatic lymph nodes. Therefore, the PR status plays an important role in determining MRI features and clinicohistological characteristics of ILC.

• 공업화학
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• 제8권1호
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• pp.76-83
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• 1997

열방성 액정고분자(TLCP)와 폴리(에틸렌 테레프탈레이트)를 혼합용매 중에서 블렌딩하였으며, 이들 블렌드는 capillary rheometer die를 통하여 $287^{\circ}C$에서 섬유상 압출물로 가공되었다. 블렌드와 제조된 복합재료의 열적 성질, 기계적 성질, 모폴로지는 DSC, 편광현미경, SEM 및 인장시험에 의하여 조사되었다. 블렌드의 결정화 동력학은 등온 DSC 방법에 의하여 측정된 데이타로부터 Avrami식을 이용하여 결정화 속도 및 결정성장 메카니즘에 대한 정보를 얻었다. 블렌드내의 액정상은 가공온도조건하에서 거대상분킥나 열분해현상을 보이지 않았으며, 액체질소 속에서 절단된 섬유 단면의 SEM 관찰에 의하면, 섬유내 TLCP domain은 $0.1{\mu}m$에서 $0.2{\mu}m$정도의 크기로 분산되었고, 두 상 계면에서의 접착은 잘 되어있음을 알 수 있었다. TLCP/PET in-situ 섬유상 복합재료의 인장강도와 모듈러스는 TLCP 함량이 많을수록, draw ratio가 높을수록 증가됨을 알 수 있었다.

• Environmental Engineering Research
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• 제11권1호
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• pp.1-13
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• 2006

In this study, conventional biofilters packed with flexible synthetic polyurethane (PU) foam carriers were operated to remove toluene from a contaminated air stream. PU foams containing various adsorbents (e.g., zeolite, sepiolite, dolomite and barite) were synthesized for the biofilter media and their adsorption characteristics of toluene were determined. Adsorption capacity of PU-adsorbent foam was in the order of PU-dolomite ${\approx}$ PU-zeolite > PU-sepiolite > PU-barite. During the biofiltration experiment, influent toluene concentration was in the range of 0-160 ppm and EBRT (i.e., empty bed residence time) was 45 seconds. Pressure drop of the biofilter bed was 4-5 mm $H_2O/m$ column height. The maximum removal capacity was in the order of PU-dolomite > PU-zeolite > PU-sepiolite > PU-barite, while the complete removal capacity was in the order of PU-dolomite > PU-sepiolite > PU-zeolite > PU-barite. The better biofiltration performance in PU-dolomite foam was because PU-dolomite foam had lower density and higher porosity than the others providing favorable conditions for microbial growth. The results of biodegradation kinetic analysis showed that PU-dolomite foam had higher maximum removal rate ($V_m\;=\;11.04\;g$ toluene/kg dry material/day) and saturation constant ($K_s\;=\;26.57\;ppm$) than the other PU foams. This supports that PU-dolomite foam was better than the others for biofilteration of toluene.

• Journal of Plant Biotechnology
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• 제39권4호
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• pp.253-260
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• 2012

애기장대 액포 소재 $H^+$-PPase(AVP1)의 과발현이 농업적으로 가치 있는 표현형을 나타낸다는 기 보고에 기초하여, AVP1 발현이 다른 종에서도 일관되게 바이오매스를 증가시키고 염에 대한 내성을 향상시키는지를 확인하기 위하여 본 연구에서는 AVP1 형질전환 배추 식물체를 획득한 후 고정계통을 육성하여 생리검정 재료로 사용하였다. 형질전환 배추 유식물체는 비형질전환 유식물체에 비해 생장이 왕성하였으며 염스트레스에 대한 내성도 강하였다. 정상 재배조건에서 생장시킨 유식물체의 생체중과 건물중을 비교함으로써 형질전환에 의한 바이오매스증가 표현형을 확인하였으며 MS 염과 NaCl로 점차 염스트레스를 강화시키는 조건에서 광계II 양자수율을 추적, DAB 염색 실시 및 최종적으로 용토 탈염 후 회복 실험을 수행함으로써 내염성 향상 표현형을 확인하였다.