• The Korean Journal of Zoology
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• v.32 no.4
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• pp.393-403
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• 1989

Using starch gel electrophoresis of proteins, we examined variation at 24 genetic loci in five species (three general of the Subfamily Danioninae (Class Pisces, Family Cyprinidae) inhabiting In Korea. The average degree of genic variation of the Subfamily Danioninae (A=1.8, P=16.5%, HD=0.043, HG=0.049) was far less than that of the fresh water fishes in general. But the degree of genic variation of A. chinensis (P=32.5 HD=0.100, HG=0.119) was highe, than other fishes and the value of O. biders was the lowest (P=4.2%, HD=0.008, HG=0.008). The average genetic similarities among the populations in each species of A. chinensis, Z. platypus, Z. temmincki MS type, Z. temmincki W type, and O. widens were S=0.902, 0.899, 0.990, 0.914, and 0.992, respectively. The average genetic similarity of A. chinensis to the other species was the lowest value of S=0.235, whereas that between two species of Z. temmincki was the highest of S=0.822. Genetically, Z. plypus is more similiar to O. widens than ho species of the same genus Zacco. Based on estimated divergent time of 5 species of the Subfamily Danioninae (7.6 to 0.9 million years) it is assumed that they are speciated during late Pliocene to middle Pleistocene epoch.

• The Korean Journal of Zoology
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• v.34 no.2
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• pp.159-172
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• 1991

It has been investigated what could be the selective marker distinguishing the immature from mature spermatozoa and whether fi -glucuronidase and fi -glucosidase are dependent on androgen in the luminal fluid of the epididymis or not. The contents of hexose, hexosamine and sialic acid in the epithelial cells, luminal fluid and spermatozoa of the epididymis were examined and the patterns of protein bands were compared in each group of the luminal fluid by SDS-PAGE. Lactate dehydrogenase, glucose-6-phosphatase, Na+ -K+ -ATPase and MgNa-ATPase showed higher activities in the cauda than the caput epididymal spermatozoa but only $Mg^2$+-ATPase activity appeared to be changed significantly. When the contents of hexose, hexosamine and sialic acid were analyzed and compared quantitatively, those of hexose were significantly different in the luminal fluid of caput and cauda epididymis, those of hexosamine in the epithelial cells and those of sialic acid in the epithelial cells and luminal fluid. When SDS-PAGE has been performed in each group, the band of MW 33-37 KD which was absent in the luminal fluid of caput epididymis appeared obviously in the luminal fluid of cauda epididymis and ako apeared in the cauda sperm crude membrane fraction. In addition, $\beta$ -glucuronidase and $\beta$ -glucosidase activities and their dependence on androgen were measured and the SDS-PAGE patiems of proteins and/or glycoproteins in the luminal fluid were examined. The activities of these two enzymes in the luminal fluid of the epididymis decreased significantly from the 5th day after castration. When testosterone was injected, the activity of $\beta$ -glucuronidase began to increase significantly from the 5th day following injection and that of $\beta$ -glucosidase from the loth day. On the other hand, the band of about MW 21 KD was newly observed in the lumen of caput epididymis when testosterone was administered.

• Journal of Veterinary Clinics
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• v.25 no.5
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• pp.340-345
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• 2008

Malassezia pachydermatis (M. pachydermatis) is a component of the normal cutaneous flora of the dog and atopic dermatitis (AD) is one of the most common diseases associated with Malassezia overgrowth in dogs. The purpose of this study was to investigate the humoral response (IgG) to extracts of M. pachydermatis of in a dog with AD. We used Western immunoblotting to identify allergens of M. pachydermatis. Gel electrophoresis of extracts proteins and immunoblotting of sera samples in both an atopic dog and a non-atopic dog were compared. Proteins of 18, 21, 26, 32, 34, 38, 40, 42, 46, 58, 64, 75, 85, and 120 kDa were observed in a serum of atopic dog. However, when serum of a non-atopic dog was used, protein bands were not identified except binding in 50 kDa protein. The results of this study indicate that atopic dogs with M. pachydermatis dermatitis may induce IgG response and also suggest that humoral response to M. pachydermatis could be important in pathogenesis of AD in dogs. However, further studies are required to identify roles of humoral response to M. pachydermatis in canine AD.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.508-513
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• 2010

Cytokines are important mediators of the immune response, and quantitating cytokine mRNA is a highly sensitive and attractive method for measuring cytokine production. The objective of the current study was to develop and validate a SYBR green quantitative real-time reverse transcriptase PCR (qRT-PCR) assay for measuring canine cytokine mRNA. The optimal annealing temperatures ($T_a$) of the designed primers were $62^{\circ}C$ for interleukin (IL)-$1{\beta}$, IL-6 and IL-10; $60^{\circ}C$ for glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and tumor necrosis factor (TNF)-${\alpha}$; and $58^{\circ}C$ for high mobility group box 1 (HMGB1). Primer efficiencies of all primers calculated for standard curve samples were between 97.1% and 102.6%. No evidence of secondary structure or primer-dimer formation was seen via melt-curve analysis or gel electrophoresis. The developed qRT-PCR assays are highly specific and sensitive and can be used to quantify gene expression levels of canine cytokines.

• Journal of Life Science
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• v.25 no.6
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• pp.673-679
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• 2015

The culture conditions needed to maximize the production of laccase from Pholiota highlandensis mycelia were investigated. Among the tested media for laccase production, Coriolus versicolor medium (CVM; 2% dextrose, 0.4% peptone, 0.6% yeast extract, 0.046% KH₂PO₄, 0.1% K₂HPO₄, 0.05% MgSO₄·7H₂O) showed the highest activity for the enzyme. Then, to optimize culture conditions for laccase activity, the influences of various carbon, nitrogen, phosphorus, and inorganic salt sources in CVM were investigated. The optimum culture medium was 2% fructose, 0.4% peptone with 0.6% yeast extract, 0.05% NaH₂PO₄, and 0.05% MgSO₄·7H₂O as carbon, nitrogen, phosphorus, and inorganic salt sources, respectively. Several aromatic compounds in the medium enhanced laccase activity to varying degrees. Guaiacol induced maximum laccase production, yielding 114.1 U/ml laccase activity after cultivation for 11 days at 25℃. The optimum pH and temperature for laccase production were 8.0 and 35℃, respectively. Native polyacrylamide-gel electrophoresis (PAGE) followed by laccase-activity staining with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as the substrate was performed to identify the presence of laccase under the optimum conditions studied. Zymogram analysis of the supernatant culture showed an enzymatic band with a molecular mass of about 90 kDa.

• Journal of Life Science
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• v.25 no.2
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• pp.249-255
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• 2015

Schisandrae fructus [Schizandra chinensis (Turcz.) Baillon] is a medicinal herb widely used for treating various inflammatory and immune diseases in East Asian countries. The Schisandrae Semen essential oil (SSeo) from this plant has pharmacological activities, including antioxidant, antimicrobial, and antitumoral activities. Nevertheless, the biological activities and underlying molecular mechanisms of the potential anti-cancer effects of this oil remain unclear. In the present study, we investigated the potential inhibition of apoptosis signaling pathways by SSeo in human leukemia U937 cells and evaluated the underlying molecular mechanism. Exposure to SSeo resulted in a concentration-dependent growth inhibition due to apoptosis, which was verified by DNA fragmentation, the presence of apoptotic bodies, and an increase in the sub-G1 ratio. Induction of apoptotic cell death by SSeo was correlated with the down-regulation of members of the inhibitor of apoptosis protein (IAP) family (including X-linked inhibitor of apoptosis protein (XIAP), cIAP-1, and surviving) and anti-apoptotic Bcl-2, and with up-regulation of death receptor (DR) 4 and DR5, depending on dosage. SSeo treatment also induced Bid truncation, mitochondrial dysfunction, proteolytic activation of caspase-3, -8 and -9, and concomitant degradation of activated caspase-3 target proteins such as poly (ADP-ribose) polymerase. Taken together, these findings suggest that SSeo may be a potential chemotherapeutic agent for use in the control of human leukemia cells. Further studies are needed to identify its active compounds.

• Journal of Life Science
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• v.26 no.9
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• pp.1007-1014
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• 2016

A highly efficient, rapid, and reliable multiplex polymerase chain reaction based method for distinguishing ten species of genus Cynoglossus (C. senegalensis, C. abbreviates, C. macrolepidotus, C. arel, C. semilaevis, C. interruptus, C. joyneri, C. lingua, C. robustus, and C. monodi) is described. The species-specific primer sets were designed base on the cytochrome oxidase subunit I gene (1,500 bp). The optimal PCR conditions and primers were selected for ten of Cynoglossus species to determine target base sequences using single PCR. Multiplex PCR using the ten pairs of primers either specifically amplified a DNA fragment of a unique size or failed, depending on each species DNA. The length of amplification fragment of 208 bp for C. senegalensis, 322 bp for C. abbreviates, 493 bp for C. macrolepidotus, 754 bp for C. arel, 874 bp for C. semilaevis, 952 bp for C. interruptus, 1,084 bp for C. joyneri, 1,198 bp for C. lingua, 1,307 bp for C. robustus, and 1,483 bp for C. monodi with the species-specific primers, visualized by agarose gel electrophoresis, allowed perfectly distinction of the Cynoglossus species. The multiplex PCR assay can be easily performed on multiple samples and attain final results in less than 6 hours. This technique should be a useful addition to the molecular typing tools for the tentative identification of Cynoglossus species.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.210-210
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• 2013

그래핀은 뛰어난 기계적, 화학적, 광학적, 전기적 특성을 가지고 있는 2차원 물질로, 대면적 합성법과 전사 공정을 통해 다양한 기판에서의 사용이 가능해지면서 차세대 전자 소자로 활용하기위한 활발한 연구가 이루어지고 있다. 디스플레이, 태양전지의 전극과 전계 효과 트랜지스터의 채널로 적용한 연구에서 우수한 결과들을 보이고 있다. 특히, 금속/금속 산화물 전극은 염료 감응형 태양전지와 유기 발광 다이오드 구조에서 화학적으로 불안정할 뿐 아니라 일함수가 고정되어 쇼트키 접촉이 형성되면 저항을 낮추기 어렵지만, 그래핀은 금속/금속 산화물 전극보다 화학적으로 안정하고 일함수의 조절이 가능해 옴 접촉 형성에 용이하다. 그래핀의 일함수를 조절하는 연구는 크게 공유결합과 비공유 결합을 이용한 방법이 시도된다. 공유 결합을 이용한 방법은 합성과정에서 그래핀의 구조에 내재된 결함 혹은 새로운 결함을 형성하여 다른 원소를 첨가하는 방법이다. 이러한 방법은 그래핀의 결함 영역에서 작용하기 때문에 그래핀 전자 구조의 높은 수준 조절을 위해선 그래핀 구조의 파괴가 동반된다. 반면, 비공유 결합을 이용한 방법은 전하 이동 도핑 효과를 이용해 그래핀의 전자 구조를 제어하는 방법으로, 금속/금속산화물/기능기와 그래핀의 적층으로 복합 구조를 형성하는 방법이다. 금속/금속 산화물과의 복합구조는 안정적인 p-형 도핑이 보고되었지만, n-형 도핑은 대기중의 수분, 산소 그리고 기판과의 상호작용에 의해 대기중에서 불안정해 추가적인 피막공정이 요구된다. 기능기를 이용한 적층 구조는 그래핀과 기판사이의 상호작용 혹은 그래핀 전자 구조를 다양한 기능기를 이용해 제어하는 것으로, 이극성을 가진 자기정렬 단일층(self-assembled monolayers)이 대표적인 방법이다. 공간기(spacer)의 길이나 말단기(end group)의 종류로 p-형과 n-형의 도핑 수준을 제어할 수 있지만, 흡착기(chemisorbing groups)의 반응성이 기판의 화학적, 물리적 표면상태에 의존하기때문에 기판 선택이 제약되며 전처리 공정이 요구될 수 있는 한계가 있다. 본 연구에서는 다양한 기판에 적용가능한 용액 공정을 이용해 그래핀과 고분자를 적층하였고, 안정적이고 효과적으로 일함수를 낮추는 구조를 확인하였다.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1146-1151
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• 1998

The crystallization behaviour of perovskite $PbTiO_3$ for the samples heat- treated at various temperatures for various times in the $PbO-TiO_2-A1_2O_3-SiO_2$, glass system has been investigated by the means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Higher crystallinity obtained in the sample heat-treated at higher temperature for longer time. With increasing heat-treatment time, dielectric constant of the samples heat-treated at $610^{\circ}C$ and $650^{\circ}C$ increased, but that of the sample heat- treated at $800^{\circ}C$ decreased. Loss tangent of the heat-treated samples was not much influenced by heat-treatment conditions. Piezodielectric charge constant was approximately $1.0\times10^{-12}~8.0$\times$10^{-12}C/N$ in the samples heat-treated at $800^{\circ}C$ for 1h, 2h, and 8h.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.120-124
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• 2016

A certain size of DNA (28-29 kb long) to be packaged into P2-size head and the mutation in sid gene of bacteriophage P4 are the major factors to overcome "P2 sir-associated helper inefficiency". To clarify whether the presence of sid mutation is essential to overcome "P2 sir-associated helper inefficiency" or not, we tested the P4 derivative, P4 delRI::kmr, which is $sid^+$ and whose genome size supposed to be 28.5 kb long in the case of being packaged into $P2_{sir3}$-sized large head. As P4 delRI::kmr showed the low EOP with P2 sir3 lysogen, P4 delRI::kmr phage stock was prepared in P2 sir3 lysogen host to increase the EOP with P2 sir3 lysogen. Through this process, P4 delRI::kmr had been adapted for P2 sir3 lysogen. With a CsCl buoyant equilibrium density gradient experiment and gel electrophoresis of the isolated DNA, it was evident that the adaptation of P4 delRI::kmr for P2 sir3 lysogen was caused by the conformational change of DNA to be packaged into large head. The burst size determination experiments with P4 delRI::kmr phage stock adapted for P2 sir3 lysogen and normal P4 delRI::kmr phage stock showed that not the sid mutation but the size of DNA to be packaged (28-29 kb long) was essential to overcome "P2 sir-associated helper inefficiency".