• 한국결정성장학회지
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• 제9권2호
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• pp.212-216
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• 1999

SiC(3C) 광다이오드는 p-형 Si 위에 tetramethylsilane (TMS)를 열분해아여 화학기상증착법으로 성장된 SiC(3C) 에피층을 성장하여 제작되었다. SiC(3C)의 전기적 특성은 홀 측정(Hall measurement) 및 전류-전압(I-V) 특성으로 조사되었다. SiC(3C) 에피층의 전도형은 n-형이었다. 저항성 접촉은 마스크 (shadow-mask)를 통해서 Al을 열증착하여 형성하였다. SiC(3C)광다이오드의 광학적 이득(photovoltaic detection)를 해석하기 위하여 SiC(3C) 에피층의 Spectral response (SR)를 전기적 변수(electrical parameter) 및 광다이오드의 기하학적 구조(geometric structure)를 고려하여 계산하였다. 적절히 선정된 변수들로부터 계산된 SR의 최대값은 550 nm에서 약 0.75이었고, 파장영역 400~600 nm 사이에서 청색 및 근자외선 광검지기로서 매우 유용하다.

• 미생물학회지
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• 제42권4호
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• pp.246-251
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• 2006

사상성 진균인 Aspergillus nidulans에서 유성분화초기단계, 또는 유성분화유도를 위한 세포내 조건 형성과정에 관여할 것으로 예상되는 유전자를 탐색하였다. 선행연구결과를 통해 유성분화를 전혀 하지 못하는 NSD (never in sexual development) 돌연변이주가 분리되어 nsdA, nsdB, nsdC, 그리고 nsdD의 4상 보군으로 동정된 바 있다. 본 연구에서는 이들 유전자 중 nsdC 유전자를 분리하고자 A. nidulans AMAl-Not I Genomic DNA library로 nsdC6 돌연변이균주를 형질전환하여 야생형처럼 유성분화를 할 수 있는 형질전환체를 분리하고 이들로부터 약 10 kb genomic DNA가 삽입된 library DNA를 분리하였다. Genomic priming system (GPS)을 이용하여 nsdC6 돌연변이를 상보하는 유전자의 부분 서열을 확보한 후 전체 DNA 염기서열을 결정하였다. 유전자분석 결과 nsdC는 intron 없이 1,929염기(643개의 아미노산)로 구성된 Open reading frame (ORF)를 가지며, 약 1kb 정도의 비교적 긴 5'-UTR 부위에 2개의 intron을 가지고 있음이 확인되었다. 또한 NsdC polypeptide의 중앙에 $C_2H_2C_2H_2C_2HC$ 형의 zinc finger DNA binding domain과 C 말단 부위에 coiled-coil domain이 존재하였다. nsdC6 돌연변이는ORF의 407 bp와 408 bp사이에 엽기 T가 삽입되어 frameshift가 일어난 것으로 밝혀졌다. 따라서 nsdC6 돌연변이균주는 단지 139개 아미노산만 갖고 있는 결실 단백질이 생산됨을 알 수 있었다.

• 식물분류학회지
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• 제49권2호
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• pp.118-126
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• 2019

The taxonomic rank of the tiny-leaved terrestrial orchid Cephalanthera subaphylla Miyabe & $Kud{\hat{o}}$ has been somewhat controversial, as it has been treated as a species or as an infraspecific taxon, under C. erecta (Thunb.) Blume [C. erecta var. subaphylla (Miyabe & $Kud{\hat{o}}$) Ohwi and C. erecta f. subaphylla (Miyabe & $Kud{\hat{o}}$) M. Hiro]. Allozyme markers, traditionally employed for delimiting species boundaries, are used here to gain information for determining the taxonomic status of C. subaphylla. To do this, we sampled three populations of five taxa (a total of 15 populations) of Cephalanthera native to the Korean Peninsula [C. erecta, C. falcata (Thunb.) Blume, C. longibracteata Blume, C. longifolia (L.) Fritsch, and C. subaphylla]. Among 20 putative loci resolved, three were monomorphic (Dia-2, Pgi-1, and Tpi-1) across the five species. Apart from C. longibracteata, there was no allozyme variation within the remaining four species. Of the 51 alleles harbored by these 17 polymorphic loci, each of the 27 alleles at 14 loci was unique to a single species. Accordingly, we found low average values of Nei's genetic identities (I) between ten species pairs (from I = 0.250 for C. erecta versus C. longifolia to I = 0.603 for C. falcata vs. C. longibracteata), with C. subaphylla being genetically clearly differentiated from the other species (from I = 0.349 for C. subaphylla vs. C. longifolia to 0.400 for C. subaphylla vs. C. falcata). These results clearly indicate that C. subaphylla is not genetically related to any of the other taxa of Cephalanthera that are native to the Korean Peninsula, including C. erecta. In a principal coordinate analysis (PCoA), C. subaphylla was positioned distant not only from C. falcata, C. longibracteata, and C. longifolia, but also from C. erecta. Finally, K = 5 was the best clustering scheme using a Bayesian approach, with five clusters precisely corresponding to the five taxa. Thus, our allozyme results strongly suggest that C. subaphylla merits the rank of species.

• 한국전기전자재료학회논문지
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• 제20권3호
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• pp.234-239
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• 2007

This paper describes the TiW ohmic contact characteristics under the surface treatment of the polycrystalline 3C-SiC thin film grown on $SiO_2/Si(100)$ wafers by APCVD. The poly 3C-SiC surface was polished by using CMP(chemical mechanical polishing) process and then oxidized by wet-oxidation process, and finally removed SiC oxide layers. A TiW thin film as a metalization process was deposited on the surface treated poly 3C-SiC layer and was annealed through a RTA(rapid thermal annealing) process. TiW/poly 3C-SiC was investigated to get mechanical, physical, and electrical characteristics using SEM, XRD, XPS, AFM, optical microscope, I-V characteristic, and four-point probe, respectively. Contact resistivity of the surface treated 3C-SiC was measured as the lowest $1.2{\times}10^{-5}{\Omega}cm^2$ at $900^{\circ}C$ for 45 sec. Therefore, the surface treatments of poly 3C-SiC are necessary to get better contact resistance for extreme environment MEMS applications.

• BMB Reports
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• 제31권4호
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• pp.307-327
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• 1998

Cytochrome c peroxidase (CcP) is a yeast mitochondrial enzyme which catalyzes the reduction of hydrogen peroxide to water using two equivalents of ferrocytochrome c. The CcP/cytochrome c system has many features which make it a very useful model for detailed investigation of heme protein structure/function relationships including activation of hydrogen peroxide, protein-protein interactions, and long-range electron transfer. Both CcP and cytochrome c are single heme, single subunit proteins of modest size. High-resolution crystallographic structures of both proteins, of one-to-one complexes of the two proteins, and a number of active-site mutants are available. Site-directed mutagenesis studies indicate that the distal histidine in CcP is primarily responsible for rapid utilization of hydrogen peroxide implying significantly different properties of the distal histidine in the peroxidases compared to the globins. CcP and cytochrome c bind to form a dynamic one-to-one complex. The binding is largely electrostatic in nature with a small, unfavorable enthalpy of binding and a large positive entropy change upon complex formation. The cytochrome c-binding site on CcP has been mapped in solution by measuring the binding affinities between cytochrome c and a number of CcP surface mutations. The binding site for cytochrome c in solution is consistent with the crystallographic structure of the one-to-one complex. Evidence for the involvement of a second, low-affinity cytochrome c-binding site on CcP in long-range electron transfer between the two proteins is reviewed.

• 제어로봇시스템학회논문지
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• 제14권1호
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• pp.81-87
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• 2008

C-Hook is a kind of conveyer system for transporting steel coil in POSCO. To detect the current position and the trajectory of steel coils in a plant, C-Hooks are tracked by an inspection system based on PLC. The inspection system detects transit of C-Hooks by monitoring a physical contact between steel bars on a C-Hook and the inspection sensors. However, this system is not reliable because of the abrasion, damage and aging. Moreover, the number of distinguishable C-Hooks is limited by the number of combination of steel bars on a C-Hook. It means that more steel bars should be installed for distinguishing the more C-Hooks. Therefore, the conventional system is difficult and expensive to maintain. To overcome these problems, we propose a C-Hook identification system that uses RFID which is a non-contact type identification system, and evaluate its performance and applicability from a new monitoring program that operates along with the conventional system in the real environment of POSCO.

• Biomolecules & Therapeutics
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• 제14권2호
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• pp.119-124
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• 2006

This study was performed to investigate the influence of the spinal adenosine $A_1$ receptors on the central regulation of blood pressure (BP) and heart rate (HR), and to define whether its mechanism is mediated by cyclic AMP (cAMP), cyclic GMP (cGMP) or potassium channel. Intrathecal (i.t.) administration of drugs at the thoracic level were performed in anesthetized, artificially ventilated male Sprague-Dawley rats. I.t. injection of adenosine $A_1$ receptor agonist, $N^6$-cyclohexyladenosine (CHA; 1, 5 and 10 nmol) produced dose dependent decrease of BP and HR and it was attenuated by pretreatment of 50 nmol of 8-cyclopentyl-1,3-dimethylxanthine, a specific adenosine $A_1$ receptor antagonist. Pretreatment with a cAMP analogue, 8-bromo-cAMP, also attenuated the depressor and bradycardiac effects of CHA (10 nmol), but not with cGMP analogue, 8-bromo-cGMP. Pretreatment with a ATP-sensitive potassium channel blocker, glipizide (20 nmol) also attenuated the depressor and bradycardiac effects of CHA (10 nmol). These results suggest that adenosine $A_1$ receptor in the spinal cord plays an inhibitory role in the central cardiovascular regulation and that this depressor and bradycardiac actions are mediated by cAMP and potassium channel.

• 한국식품과학회지
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• 제14권2호
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• pp.125-129
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• 1982

식품(食品)의 열 처리 공정중에 일어나는 페르옥시다아제의 열(熱) 불활성화(不活性化) 특성(特性)을 알기 위하여 서양고추냉이 뿌리에서 4개의 페르옥시다아제 이소짐(isozyme A, B, C 및 D)을 분리하고 pH 7.0, 온도범위 $70{\sim}97^{\circ}C$에서 각 이소짐 별로 열(熱) 불활성화(不活性化) 실험(實驗)을 행하였다. 각 이소짐의 열 저항성이 서로 크게 달랐고 $80^{\circ}C$에서는 C, B, A, D의 순서로 열에 강하였으며 각 이소짐의 열 불활성화는 1차반응에서 벗어났다. 이소짐 A, B, C 및 D의 $D_{80}$값은 각각 594초, 1850초, 2050초 및 78초 이었고 z값은 각각 $24.0^{\circ}C$, $12.5^{\circ}C$, $18.0^{\circ}C$ 및 $23.7^{\circ}C$이었으며 조효소의 $D_{80}$값은 130초, z값은 $24.0^{\circ}C$이었다. 이소짐 C를 열처리 했을 때에는 원래의 효소분자보다 분자량이 큰 단백질과 작은 단백질이 생성되었으며 이들은 효소활성이 없었다.

• 한국축산식품학회지
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• 제44권3호
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• pp.684-698
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• 2024

We investigated Cissus quadrangularis L. powder (C) use as a natural additive to Tteokgalbi, a traditional Korean meat-based dish. Five distinct Tteokgalbi samples were treated: one without any additives (negative control, NC), one with 1.00% C (C1), 2.00% C (C2), 4.00% C (C3), and 0.10% ascorbic acid (positive control, PC). C addition resulted in changes in composition, quality, and sensory attributes. Moisture content decreased with higher C levels; crude protein varied among the groups, with C1 having the highest crude protein levels and C3 the lowest. Crude fat decreased with increasing C concentration, whereas the carbohydrate content increased. The water-holding capacity notably decreased in the C3 group, resulting in increased cooking loss with higher C concentrations. C treatment altered color and texture, reducing CIE L^* and increasing CIE a^* before cooking and increasing CIE L^* and CIE a^* after cooking. CIE b^* decreased before cooking but increased thereafter. C-treated Tteokgalbi was less cohesive, chewy, and brittle compared to the NC. The C treatment increased the total phenolic and flavonoid contents and enhanced radical scavenging capacities. It also affects storage characteristics, lowers pH, and increases 2-thiobarbituric acid reactive substances values. The microbial counts were lower in C2 and C3 after 11 days. These findings suggest the potential use of C as a natural meat additive.

• 한국식품과학회지
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• 제20권6호
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• pp.856-861
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• 1988

본 실험은 Staphylococcus aureus의 한 균주로부터 A와 C, 두 종류의 toxin이 동시에 생성될 때 이들의 동시분리를 위하여 각종 분리방법을 연구하였다. 혼합된 toxin A와 C는 CM-column chromatography를 이용하여 pH-gradient법으로 용출했을 때 2개의 분획이 나타났으나 서로 완전히 분리되지 않아 다량의 서로 다른 toxin이 함유되어 있었고 Sephadex G-75, Sephacryl S-300, 그리고 ultro gel을 사용한 gel filtration에서는 하나의 분획을 나타내 상호분리가 불가능 하였으며 정제도와 분리도에서 가장 뛰어난 gel column을 이용한 FPLC도 toxin A와 C를 상호분리할 수 없었다. 그러나 CM-column을 이용한 FPLC에서는 enterotoxin A는 pH 6.8에서 그리고 enterotoxin C는 pH 8.6에서 각각 분리되었으며, immunodiffusion test 결과 enterotoxin A의 분획에서는 toxin C가 전혀 검출되지 않았고 enterotoxin C의 분획에서도 toxin A가 검출되지 않았다. 용출방법에 있어서는 CM-column을 이용한 FPLC에서 pH-stepwise법이나 pH-gradient법으로 enterotoxin A와 C type을 쉽게 동시에 분리할 수 있었다.