• 농업과학연구
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• 제51권2호
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• pp.169-178
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• 2024

Cordyceps militaris L. (C. militaris) has been traditionally used as tonic medicine for metabolic syndrome. Cordycepin, has been reported with immunomodulatory, antitumor, and hepatoprotective effect, is the main extract from C. militaris. This study was conducted to evaluate the alcohol degradation and hepatoprotective effect of cordycepin-enriched C. militaris extract (CM) powder in chronic and binge ethanol (ethanol Lieber-DeCarli diet)-fed male C57BL/6 Mice. Cordycepin-enriched C. militaris extract powder was orally administered once daily at dose levels of 0, 125, 250, and 500 mg·kg^-1·day^-1 for 16 days. For evaluating alcohol degradation, ethanol concentration and alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity were measured in serum. Serum ethanol (EtOH) concentration was decreased at CM treated groups, and the activities of ADH and ALDH were increased dose-dependently at CM treated groups compare to EtOH model group. In clinical chemistry, the values of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were lower in CM treated groups than those in EtOH model group. Additionally, absolute and relative (to body weight) liver weights were statistically decreased in the CM treated groups compared to the EtOH model group. In conclusion, our study showed that cordycepin-enriched C. militaris extract powder exhibits hepatoprotective effect by upregulating the ADH and ALDH enzyme in an alcoholic liver disease model.

• 한국균학회지
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• 제38권2호
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• pp.89-94
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• 2010

농업경영측면에서, 또 균학적생화학적 측면에서도 식물을 침해하는 진균들의 연구는 반드시 필요하며 병 발생이나 저항성 발현 기작 구명은 기주와 기생체에 대한 연구를 동시에 진행해야 정확히 파악할 수 있다. 현재 병원균이 생산하는 분비체상과 비병원성 인자에 대한 연구는 많은 경우 세균에서 수행되고 있으며 사상균 중 조균인 Phytophthora와 진균인 Cladosporium에서만 병원균의 effector 복합체와 기주의 저항성 기제 간 관계가 같이 진행되고 있을 뿐이다. 앞에서 살펴보았듯 진균-기주 체계에서 단백질 분해가 병원성 조절 및 침입에 관여한다고 정확히 알려진 것은 단지 수종에 불과하며 그 기작도 세포자가포식과 ubiquitin 부가반응에 제한되어 있다. Post translational modification과 단백질 분해기작이 대단히 다양하고 거의 모든 진핵생물 체계에서 관찰되고 있음을 고려할 때 단백질 분해 과정은 세균 뿐 아니라 진균에서도 병원성 발현과 저항성 조절에 참여하고 있을 것으로 생각되며 이에 대한 연구가 앞으로 계속 요구될 것이라 생각된다.

• Journal of Microbiology and Biotechnology
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• 제31권11호
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• pp.1559-1567
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• 2021

The root bark of Morus alba L. has cytotoxic activity against several types of cancer cells. However, little is known about its chemopreventive mechanisms and bioactive metabolites. In this study, we showed that M. alba L. root bark extracts (MRBE) suppressed β-catenin response transcription (CRT), which is aberrantly activated in various cancers, by promoting the degradation of β-catenin. In addition, MRBE repressed the expression of the β-catenin/T-cell factor (TCF)-dependent genes, c-myc and cyclin D1, thus inhibiting the proliferation of RPMI-8226 multiple myeloma (MM) cells. MRBE induced apoptosis in MM cells, as evidenced by the increase in the population of annexin VFITC-positive cells and caspase-3/7 activity. We identified ursolic acid in MRBE through LC/mass spectrum (MS) and observed that it also decreased intracellular β-catenin, c-myc, and cyclin D1 levels. Furthermore, it suppressed the proliferation of RPMI-8226 cells by stimulating cell cycle arrest and apoptosis. These findings suggest that MRBE and its active ingredient, ursolic acid, exert antiproliferative activity by promoting the degradation of β-catenin and may have significant chemopreventive potential against MM.

• 한국세라믹학회지
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• 제47권2호
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• pp.189-194
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• 2010

Compared with organic fluorophores, semiconductor quantum dots (QDs) have the better properties such as photostability, narrow emission spectra coupled to tunable photoluminescent emissions and exceptional resistance to both photo bleaching and chemical degradation. In this work, CdSe/ZnS QDs nanobeads were prepared by the incorporation of CdSe/ZnS QDs with mesoporous silica to use as the optical probe for detecting toxic and bio- materials with high sensitivity, CdSe/ZnS core/shell QDs were synthesized from the precursors such as CdO and zinc stearate with the lower toxicity than pyrotic precursors. The QD-nanobeads were characterized by transmission electron microscopy, FL microscopy, UV-Vis and PL spectroscopy, respectively.

• 환경영향평가
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• 제24권4호
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• pp.344-351
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• 2015

본 연구에서는 비소로 오염된 지역의 토양 및 지하수에 동전기적 기술을 사용하고 배양된 토양 미생물과 배양액을 주입하여 토양 내의 토착 미생물을 활성화하여 비소의 이동도를 상승시키는 것이 주요목표이다. 생물학적 동전기법은 미생물의 전기적 이동을 이용하여 기존의 생물학적 복원에서 문제시 되어온 늦은 분해속도와 낮은 제거효율의 단점을 극복할 수 있었다. 이는 전극의 전해액 대신 토양 미생물과 배양액을 혼합 주입하여 유기물질을 전자 공여체로 이용하는 다양한 토양 미생물이 Fe, Mn 등을 환원하게 된다. 이에 따라 주변의 금속 산화 미생물이 As(III)를 As(V)로 변환시킴으로써 As(III)의 이동도가 증가하게 되고, 이로 인해 As의 이동도가 기존 동전기법의 약 30%에 비해 60 ~ 70%정도로 상승함을 확인하였다.

• 한국진공학회지
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• 제17권3호
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• pp.199-203
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• 2008

$O_2$ 플라즈마를 이용한 표면처리 공정이 Bio-FET (biologically sensitive field-effect transistor)에 미치는 영향을 조사하기 위하여, SOI (Silicon-on-Insulator) wafer와 sSOI (strained- Si-on-Insulator) wafer를 이용하여 pseudo-MOSFET을 제작하고 $O_2$ 플라즈마를 이용하여 표면처리를 진행하였다. 제작된 시료들은 back gated metal contact junction 방식으로 측정되었다. $I_D-V_G$ 특성과 field effect mobility 특성의 관찰을 통하여 $O_2$ 플라즈마 표면처리에 따른 각 시료들의 전기적 특성 변화에 대하여 관찰하였다. 그리고 $O_2$ 플라즈마 표면처리 과정에서 플라즈마에 의한 손상을 받은 시료들은 2% 수소희석가스 ($H_2/N_2$)를 이용한 후속 열처리 공정을 진행한 후 전기적 특성이 향상되는 것을 관찰할 수 있었다. 이는 수소희석가스를 이용한 후속 열처리 공정을 통하여 산화막과 Si 사이의 계면 준위와 산화막 내부의 전하 포획 준위를 감소시켰기 때문이다.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.602-608
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• 2010

An atrazine-degrading bacterium, strain KU001, was obtained from a sugarcane field at the Cane and Sugar Research and Development Center at the Kasetsart University, Kamphaeng Saen Campus, Thailand. Strain KU001 had a rod-to-coccus morphological cycle during growth. Biolog carbon source analysis indicated that the isolated bacterium was Arthrobacter histidinolovorans. Sequence analysis of the PCR product indicated that the 16S rRNA gene in strain KU001 was 99% identical to the same region in Arthrobacter sp. The atrazine degradation pathway in strain KU001 consisted of the catabolic genes trzN, atzB, and atzC. Strain KU001 was able to use atrazine as a sole nitrogen source for growth, and surprisingly, atrazine degradation was not inhibited in cells grown on ammonium, nitrate, or urea, as compared with cells cultivated on growth-limiting nitrogen sources. During the atrazine degradation process, the supplementation of nitrate completely inhibited atrazine degradation activity in strain KU001, whereas ammonium and urea had no effect on atrazine degradation activity. The addition of strain KU001 to sterile or nonsterile soils resulted in the disappearance of atrazine at a rate that was 4- to 5-fold more than that achieved by the indigenous microbial community. The addition of citrate to soils resulted in enhanced atrazine degradation, where 80% of atrazine disappeared within one day following nutrient supplementation.

• Journal of the Korean Wood Science and Technology
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• 제44권3호
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• pp.350-359
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• 2016

본 연구에서는 팜 부산물인 empty fruit bunch (EFB)의 시료 특성을 분석하고 유동형 열분해기를 이용하여 $400{\sim}550^{\circ}C$ 범위에서 체류시간 1.3초간 급속열분해 공정을 진행하였다. 또한, 반응온도에 따른 열분해 주요 산물(바이오오일, 바이오차, 가스)의 수율과 물리화학적 특성 변화를 구명하였다. EFB의 화학조성 및 원소분석을 통해 시료 내 칼륨 함량이 8400 ppm으로 많은 것을 확인하였다. 열중량분석에서 나타난 특성으로 볼 때 EFB 시료 내 칼륨의 촉매작용에 의해 셀룰로오스의 분해가 촉진된 것으로 추측된다. $500^{\circ}C$까지의 온도범위에서는 바이오오일의 수율이 증가하고 가스의 수율이 감소하였으며 바이오차는 수율에 큰 변화가 없었던 반면, $500{\sim}550^{\circ}C$까지의 온도범위에서는 바이오오일과 바이오차의 수율이 감소하였고 가스의 수율이 증가하였다. 각 조건별로 생성된 바이오오일은 수분함량 20~30%, 발열량 15~17 MJ/kg 범위의 값을 나타냈으며, 점도 11 cSt (centistoke), 전산가(total acid number) 100 mg KOH/g oil 미만으로 나타났다. 기체크로마토그래프 분석을 통해 EFB 바이오오일로부터 셀룰로오스계 화합물(9종)과 리그닌계 화합물(17종)을 확인하였다. 리그닌계 화합물 중 특히 phenol이 다량 검출되었으며 이는 전체 화합물 농도의 25%에 해당하는 양이다.

• Journal of Microbiology and Biotechnology
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• 제25권11호
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• pp.1773-1781
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• 2015

Environmental security is one of the major concerns for the safety of living organisms from a number of harmful pollutants in the atmosphere. Different initiatives, legislative actions, as well as scientific and social concerns have been discussed and adopted to control and regulate the threats of environmental pollution, but it still remains a worldwide challenge. Therefore, there is a need for developing certain sensitive, rapid, and selective techniques that can detect and screen the pollutants for effective bioremediation processes. In this perspective, isolated enzymes or biological systems producing enzymes, as whole cells or in immobilized state, can be used as a source for detection, quantification, and degradation or transformation of pollutants to non-polluting compounds to restore the ecological balance. Biosensors are ideal for the detection and measurement of environmental pollution in a reliable, specific, and sensitive way. In this review, the current status of different types of microbial biosensors and mechanisms of detection of various environmental toxicants are discussed.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.251-251
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• 2006

A real time bio-imaging of HA degradation was successfully carried out using HA-quantum dot conjugates. HA-ADH with ADH content of ca. 70 mol% was synthesized and conjugated with quantum dots containing carboxyl terminal ligands which were activated by the addition of HOBt and EDC in DMSO. When the concentration of HA-ADH solution was higher than 4 wt%, HA-ADH hydrogels incorporating quantum dots could be synthesized in 30 minutes. These novel HA-quantum dot conjugates and the precursor solution of HA hydrogels incorporating quantum dots were injected to the nude mouse and investigated to elucidate the biological roles of HA in the body for various future tissue engineering applications.