• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2419-2431
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• 2023

Experiments related to Boron Neutron Capture Therapy (BNCT) accomplished at the Institute of Nuclear Techniques (INT), Budapest University of Technology and Economics (TUB) are presented. Relevant investigations are required before designing BNCT for vivo applications. Samples of relevant boron compounds (H₃BO₃, BDTPA) usually employed in BNCT were investigated with neutron beam. Channel #5 in the research reactor (100 kW) of INT-TUB provides the neutron beam. Boron samples are mounted on a carrier for neutron irradiation. The particle attenuation of several carrier materials was investigated, and the one with the lowest attenuation was selected. The effects of boron compound type, mass, and compound phase state were also investigated. To detect the emitted charged particles, a traditional ZnS(Ag) detector was employed. The neutron beam's interaction with the detector-detecting layer is investigated. Graphite (as a moderator) was employed to change the neutron beam's characteristics. The fast neutron beam was also thermalized by placing a portable fast neutron source in a paraffin container and irradiating the H₃BO₃. The obtained results suggest that the direct measurement approach appears to be insufficiently sensitive for determining the radiation dose committed by the Alpha particles from the ¹⁰B (n,α) reaction. As a result, a new approach must be used.

• 한국작물학회지
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• 제28권1호
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• pp.12-40
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• 1983

우리나라 수도 품종의 시대적 변천에 따른 그들 품종의 생육형질 및 수량구성형질들의 변이를 조사비교하여 앞으로 품종육성 및 재배기술 발전에 필요한 기초자료를 얻고자 연대별 주요품종을 5개씩 25개 품종을 공시하여 5대 품종군, 즉 ${circled1}$1907년대의 재래품종들을 GI군, ${circled2}$ 1920년대의 도입품종들을 GII군 ${circled3}$ 1930년대에 육성 보급된 품종들을 GIII군, ${circled4}$ 1950년대에 육성 보급된 품종들을 GIV군, ${circled5}$ 1971년 통일품종 육성이후에 육성된 품종들을 GV군으로 구분하여 이앙시기를 5월 15일, 5월 30일, 6월 14일 및 6월 29일의 4회로 하여 시험조사 하였는데 그 결과는 다음과 같다.

• 폴리머
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• 제25권2호
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• pp.186-198
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• 2001

pH와 온도에 민감한 N-isopropylacrylamide (NIPAAm)계 공중합체인 poly(NIPAAm-co-AAc), Poly(NIPAAm-co-AAm-GAc), 및 poly(NIPAAm-co-AMPS)를 산성 공단량체의 조성비를 달리하여 자유라디칼 중합법에 의해 제조하였다. 합성된 공중합체들의 하한임계용액온도 거동(LCST)에 대한 pH와 공단량체의 구조 및 함량변화 효과를 열광학분석기 (TOA)를 이용하여 측정한 흐림점으로부터 결정하였다. Poly(NIPA.Am-co-AAc) 수용액의 상전이온도(T$^{p}$ )는 공중합체내 AAc의 카르복실기가 이온화될수록, 보다 높은 값을 나타내었는데, 이와 같은 현상은 이온화된 상태에서 공중합체내 이온기들간의 정전기적 반발력이 보다 친수성을 나타나게 한 원인이 되었다. 반면에, 2-acrylamido glycolic acid (AAmGAc)가 공중합체에 도입된 경우, pH 3보다 낮은 pH에서는 T$^{p}$ 의 변화가 거의 없었지만, pH 3에서 5까지는 T$^{p}$ 가 매우 급격히 증가하였다가 pH 6이상에서는 공중합체의 T$^{p}$ 가 ionic screen effect에 의해 pH 3에서 pH 5일 때보다 오히려 더 낮아졌다. 또한 이 같은 ionic screen effect는 강산성 공단량체로 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS)가 도입된 공중합체 의 경우에서도 관찰되었다.

• 약학회지
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• 제57권5호
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• pp.330-336
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• 2013

"The Act on Medication Treatment of Sexual Impulse of Sex Offenders" known as chemical castration has been effective since July 2011 in Korea. According to the law, monitoring of male sex hormone in urine is enforced to request National Forensic Service more than once a month after injection of medicine designed to reduce sex impulse. We established a rapid and sensitive method for the monitoring of testosterone (T) and epitestosterone (E) in human urine by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Three mL of urine was pretreated by solid-phase extraction for purification and performed enzymatic hydrolysis. The pretreated samples were extracted twice with 2 ml of ethyl acetate and n-hexane (2 : 3). The separation was applied on Thermo Hypersil GOLD C18 column ($1.9{\mu}m$, $100{\times}2.1mm$). A gradient elution of methanol and water of 0.1% formic acid were used as mobile phase and the retention time was less than 10 min. LC-MS/MS system coupled with an electrospray ionization source was performed in multiple reaction monitoring mode. The transitions of the analytes executed as following: m/z $289{\rightarrow}97$, 109 for T and E, m/z $292{\rightarrow}109$ for $T-d_3$ and $E-d_3$ as internal standards. The validation results of the method were satisfactory. The limits of detection were 0.05 ng/ml and the limits of quantification were 0.1 ng/ml. This method was successfully applied to real human urine sample. The developed method will be useful for monitoring T/E ratio in urine of sex offenders.

• 미생물학회지
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• 제43권1호
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• pp.1-6
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• 2007

Epstein-Barr virus (EBV), cytomegalovirus (CMV), hepatitis B virus (HBV), parvovirus B19 (B19)등 4종의 바이러스는 인체에 감염을 일으키는 병원체로서 DNA를 유전물질로 함유한다. 각 바이러스 유전자의 염기서열을 분석하여 EBV CMV, HBV의 pol 유전자와 B19의 ns 유전자에 특이적으로 결합할 수 있는 primer를 설계 제작하고 단일 시험으로 4종의 바이러스를 동시에 검출할 수 있는 다중 중합효소 연쇄반응(Multiplex PCR)법을 확립하였다. Primer 염기서열, PCR 반응조성물의 농도, PCR 반응시간 및 온도조건을 최적화하여 민감도를 증대시킴으로써, 단일 시험으로 5-10 분자수의 유전물질까지 검출이 가능하였다. 또한 4종의 바이러스 사이에 교차반응이 일어나지 않았으며 생체시료를 이용한 시험에서도 특이성과 민감도가 유지됨을 확인하였다. 그러므로 본 연구에서 확립한 다중 중합효소 연쇄반응은 세포배양액 또는 생체 시료에 감염된 4종 DNA 바이러스진단에 효율적으로 이용할 수 있을 것이라고 판단된다.

• Mycobiology
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• 제43권1호
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• pp.31-36
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• 2015

We have previously isolated ${\varepsilon}$-COP, the ${\alpha}$-COP interactor in COPI of Aspergillus nidulans, by yeast two-hybrid screening. To understand the function of ${\varepsilon}$-COP, the $aneA^+$ gene for ${\varepsilon}$-COP/AneA was deleted by homologous recombination using a gene-specific disruption cassette. Deletion of the ${\varepsilon}$-COP gene showed no detectable changes in vegetative growth or asexual development, but resulted in decrease in the production of the fruiting body, cleistothecium, under conditions favorable for sexual development. Unlike in the budding yeast Saccharomyces cerevisiae, in A. nidulans, over-expression of ${\varepsilon}$-COP did not rescue the thermo-sensitive growth defect of the ${\alpha}$-COP mutant at $42^{\circ}C$. Together, these data show that ${\varepsilon}$-COP is not essential for viability, but it plays a role in fruiting body formation in A. nidulans.

• 한국자기학회지
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• 제13권3호
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• pp.127-132
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• 2003

자성유체의 자연대류는 부력 이외에 자기체적력이 존재하기 때문에 뉴턴유체와 다르다. 본 연구에서는 좌측 및 우측 벽면이 고온 및 저온으로 설정된 정방형 케비티 공간내에서 자성유체의 자연대류를 실험하였다 실험은 열전대에 의한 온도측정과 감온액정에 의한 가시화를 실시하였다. 그 결과 케비티 공간내 자성유체의 전열특성 및 외부에서 가하는 자장의 방향과 세기에 따라 자연대류가 제어됨을 알 수 있었다.

• 한국균학회지
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• 제35권1호
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• pp.1-10
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• 2007

세포벽은 진균류의 생존과 삼투안전성 유지에 필수적인 구조체로, 세포부착성 단백질이나 가수분해효소 등과 같은 생물학적 활성을 갖는 다양한 단백질이 결합하거나 그 속에 자리잡고 작용할 수 있게 한다. 최근 효모류인 Saccharomyces cerevisiae와 사상균인 Aspergillus nidulans에서 세포 내 단백질 분비 소낭의 하나인 COPI 소낭을 구성하는 ${\alpha}-COP$ 단백질에 돌연변이가 일어날 경우, 온도의존적 삼투감수성이 나타나는 것으로 밝혀졌다. 이러한 사실은 ${\alpha}-COP$이 베타-1,3-글루칸 합성효소 복합체를 구성하는 단백질과 세포벽 단백질의 이송과정에 중요한 역할을 함으로써 세포벽 안정성 유지에 기여함을 시사하는 것이다. 본 총설에서는 세포 내 단백질 이송기구 중에서도 COPI 소낭을 구성하는 ${\alpha}-COP$과 균류의 세포벽 형성과정과의 관계에 대하여 기술하는 한편, 단백질 분비기구에 결손이 생긴 돌연변 이주를 이용한 세포벽 합성기작에 대한 기초 및 응용연구의 가능성에 대하여 검토하여 보았다.

• Molecules and Cells
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• 제43권6호
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• pp.572-580
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• 2020

Transient receptor potential ankyrin 1 from rattlesnakes (rsTRPA1) and boas (bTRPA1) was previously proposed to underlie thermo-sensitive infrared sensing based on transcript enrichment in infrared-sensing neurons and hyper-thermosensitivity expressed in Xenopus oocytes. It is unknown how these TRPA1s show thermosensitivities that overwhelm other thermoreceptors, and why rsTRPA1 is more thermosensitive than bTRPA1. Here, we show that snake TRPA1s differentially require Ca²⁺ for hyper-thermosensitivity and that predisposition to cytosolic Ca²⁺ potentiation correlates with superior thermosensitivity. Extracellularly applied Ca²⁺ upshifted the temperature coefficients (Q10s) of both TRPA1s, for which rsTRPA1, but not bTRPA1, requires cytosolic Ca²⁺. Intracellular Ca²⁺ chelation and substitutive mutations of the conserved cytosolic Ca²⁺-binding domain lowered rsTRPA1 thermosensitivity comparable to that of bTRPA1. Thapsigargin-evoked Ca²⁺ or calmodulin little affected rsTRPA1 activity or thermosensitivity, implying the importance of precise spatiotemporal action of Ca²⁺. Remarkably, a single rattlesnake-mimicking substitution in the conserved but presumably dormant cytosolic Ca²⁺-binding domain of bTRPA1 substantially enhanced thermosensitivity through cytosolic Ca²⁺ like rsTRPA1, indicating the capability of this single site in the determination of both cytosolic Ca²⁺ dependence and thermosensitivity. Collectively, these data suggest that Ca²⁺ is essential for the hyper-thermosensitivity of these TRPA1s, and cytosolic potentiation by permeating Ca²⁺ may contribute to the natural variation of infrared senses between rattlesnakes and boas.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.177-182
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• 2012

A new composition of standardized Scutellariae Radix extract (HPO12) was developed for treatment of Alzheimer's disease. For the preclinical pharmacokinetic study of HPO12, a rapid, sensitive, and selective LCMS/MS method was developed and validated for the simultaneous determination of 4 bioactive compounds, baicalein, baicalin, wogonin, and wogonoside. After extraction with ethylacetate, chromatographic analysis was performed on a Thermo $C_{18}$ column ($150mm{\times}2.1mm$, $3{\mu}m$) with a mobile phase consisting of 0.1% formic acid (A) and 0.1% formic acid in 95% acetonitrile (B) by using gradient elution at a flow rate of $250{\mu}L/min$. Analytes introduced to a mass spectrometer were monitored by multiple reaction monitoring (MRM) in positive ion mode. Using $25{\mu}L$ of plasma sample, the method was validated over the following concentration ranges: 25-5000 ng/mL for baicalein, 20-40000 ng/mL for baicalin, 1-1000 ng/mL for wogonin, and 5-10000 ng/mL for wogonoside. The intra- and inter-day precision and accuracy of the quality control samples at the 4 concentrations showed $\leq$ 13.7% relative standard deviation (RSD) and 86.6-105.5% accuracy. The method was successfully applied to determine the concentrations of baicalein, baicalin, wogonin, and wogonoside in rat plasma after intraperitoneal and oral administrations of HPO12.