검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 90

        1.
        2023.10 구독 인증기관·개인회원 무료
        모기는 감염병을 매개하는 종으로 전염병 확산 억제를 위해서는 개체수의 감시와 정확한 예측이 필요하다. 본 연구에서는 모기 개체수 및 기상 및 현장 자료를 활용해 모기 개체수 머신러닝 모델을 개발하였다. 모기 개체수는 디지털 모기 측정기(Digital Mosquito Monitoring System, DMS)의 2015 년~2022년의 5월~10월의 자료를 활용하였다. 기상 자료는 기온, 강수량, 풍속, 습도를 사용하였으며, 현장 조사 자료는 현장을 명목척도와 서열척도로 나누어 기록하여, 명목 척도의 경우 원핫 인코딩으 로 변환해 수치화하여 사용하였다. 분석에 사용된 머신러닝 모델은 Artificial Neural Network, Random Forest, Gradient Boosting Machine, Support Vector Machine이며 성능지표로 R2, RMSE를 사용하였다. 연구 결과, Gradient Boosting 모델이 R2 0.4, RMSE 22.45로 가장 좋은 성능을 나타냈다. 현장 조사 자료 를 분석에 활용하였을 때 R2는 증가하였고, RMSE는 감소하였다. 본 연구 결과 모기 개체수에 현장 조사 자료가 예측 정확도를 향상시킬 수 있음을 확인하였다.
        5.
        2018.11 구독 인증기관·개인회원 무료
        To test the muscle cell specific gene expression, we examined the ability of human α-skeletal muscle actin (ACTA) promoter or human myoglobin (hMb) promoter to direct the expression of the GFP gene in both muscle and non-muscle cells, respectively. C2C12 cells, a mouse myoblast cell line, provide a powerful model to study skeletal muscle differentiation in vitro. We intended to use this cell line as a model for skeletal muscle-specific gene expression during myogenic differentiation from myoblast to myotubes. We compared marker gene expression profiles of proliferating and differentiated C2C12 cells using RT-PCR and fluorescent microscopy analysis. Also, we found that the expression of PCK1 gene under the control of ACTA promoter was proportionally increased as C2C12 differentiated into myotube form. PCK1 is involved in the regulation of gluconeogenesis. In previous research, transgenic mice with overexpressing PCK1 in skeletal muscle showed a greatly enhanced level of physical activity, which extends well into old age. This is due, in part, to an increased number of mitochondria and a high concentration of triglyceride in their skeletal muscles. These mice also had very little body fat, despite eating 60% more than controls. We also constructed a mesenchymal stem cell line and fetal fibroblast cell line for the experiments aiming to make transgenic animals in which the PCK1 gene is specifically expressed in muscle tissue. Accumulated knowledge of this approach could be applicable to a variety of related biological areas including transgenic animal research, gene function study, anti-aging study, etc. This work was supported by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through Export Promotion Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA) (316002-5).
        6.
        2018.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Electrochemical properties and performance of composites performed by incorporating metal oxide or metal hydroxide on carbon materials based on graphene and carbon nanotube (CNT) were analyzed. From the surface analysis by field emission scanning electron microscopy and field emission transmission electron microscopy, it was confirmed that graphene, CNT and metal materials are well dispersed in the ternary composites. In addition, structural and elemental analyses of the composite were conducted. The electrochemical characteristics of the ternary composites were analyzed by cyclic voltammetry, galvanostatic charge-discharge tests, and electrochemical impedance spectroscopy in 6 M KOH, or 1 M Na2SO4 electrolyte solution. The highest specific capacitance was 1622 F g–1 obtained for NiCo-containing graphene with NiCo ratio of 2 to 1 (GNiCo 2:1) and the GNS/single-walled carbon nanotubes/Ni(OH)2 (20 wt%) composite had the maximum specific capacitance of 1149 F g–1. The specific capacitance and rate-capability of the CNT/MnO2/reduced graphene oxide (RGO) composites were improved as compared to the MnO2/RGO composites without CNTs. The MnO2/RGO composite containing 20 wt% CNT with reference to RGO exhibited the best specific capacitance of 208.9 F g–1 at a current density of 0.5 A g–1 and 77.2% capacitance retention at a current density of 10 A g–1.
        4,200원
        14.
        2016.10 구독 인증기관·개인회원 무료
        Human interferon alpha 2b (hIFNα-2b) is an important immune regulator widely used in clinic, for the treatment of chronic hepatitis, hairy cell leukemia, chronic myelogenous leukemia and multiple myeloma, etc. The clinically used hIFNα-2b is generally produced by E. Coli, which lacks the post-translational O-glycosylation of naturally synthesized protein, and has a short serum half-life. In this study, we report the successful generation of transgenic chickens that produce hIFNα-2b in the egg white using a feline immunodeficiency virus (FIV)-based lentiviral vector. In preliminary in vitro study, the hIFNα-2b gene under the control of CMV promoter expressed as much as 2,650 ng/㎖ in CEF-LNC-hIFNα-2bW cell. A FIV vector packaged with vesicular stomatitis virus G glycoprotein (VSV-G) was injected underneath the blastoderm of freshly laid chicken eggs (stage X) to produce a hIFNα -2b transgenic chicken. Out of 187 injected eggs, 55 chicks were hatched after 21 days of incubation, and 27 of the G0 hatched chicks expressed the vector-encoded hIFNα-2b gene. The expression of recombinant hIFNα-2b in transgenic chickens constitutes an important step towards low-cost and full biological activity production of this protein drug in bioreactor. This work was supported by the Bio-industry Technology Development Program, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea, and by a grant from the Next-Generation BioGreen 21 Program (No. PJ011178), Rural Development Administration, Republic of Korea.
        15.
        2016.10 구독 인증기관·개인회원 무료
        In the present study, using a MoMLV-based retrovirus vector, we successfully generated a new transgenic chicken line expressing high levels of hEPO. A replication-defective Moloney murine leukemia virus (MoMLV)-based vectors packaged with vesicular stomatitis virus G glycoprotein (VSV-G) was injected beneath the blastoderm of non-incubated chicken embryos (stage X). One rooster was mated to wild-type hens to produce 748 G1 progeny. PCR analysis of blood samples from these progeny revealed that there were seven G1 transgenic offspring, corresponding to a 0.9% germline transmission rate. Subsequently, Southern blot analysis of the genomic DNA from three G1 transgenic chickens was carried out to verify the stable genomic integration and copy number of the transgene in the genome. Quantitative analyses of the blood samples taken from G1 transgenic chickens resulted in 4,150 ~ 10,823 IU/㎖ (34.6 ~ 90.2 ㎍/㎖) of hEPO in the blood. The biological activity of the recombinant hEPO in transgenic chicken serum was comparable to its commercially available counterpart. Red blood cell numbers were more than three-fold higher in the transgenic chickens compared to the non-transgenic chickens. Successful germline transmission of the transgene was also confirmed in G2 transgenic chicks produced from crossing G1 transgenic roosters with non-transgenic hens. We confirmed that 13 transgenic chicks of 45 G2 progeny, corresponding to a 28.9% germline transmission rate. These results will help establish a useful transgenic chicken model system for studies of embryonic development and for efficient production of transgenic chickens as bioreactors. This work was supported by the Bio-industry Technology Development Program, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea, and by a grant from the Next-Generation BioGreen 21 Program (No. PJ011178), Rural Development Administration, Republic of Korea.
        16.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We quantified temporal and spatial changes in the habitat for fish populations, the distribution of mandarin fish(Siniperca scherzeri) and an introduced species, largemouth bass(Micropterus salmoides) in Lake Paro and inflowing streams. The number of fish species identified in Lake Paro and the tributary streams included 10 families, 24 species and 10 families 30 species, respectively. The dominant fish species in Lake Paro were Zacco platypus, Hemibarbus labeo, Squalidus gracilis majimae, S. scherzeri and Tridentiger brevispinis, Z. platypus, Z. koreanus, and S. gracilis majimae in the inflowing streams. Although the habitat segregation for S. scherzeri and M. salmoides occurs, these two species showed the use of the fishes of the family Gobiidae as an important prey item based on IRI analysis. S. scherzeri and M. salmoides preyed mainly on T. brevispinis(67.4 %) and R. brunneus(84.0 %), respectively. The species preyed on by S. scherzeri and M. salmoides were benthic fishes that inhabit shallow water depths around the lake and have little swimming ability.
        4,200원
        17.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Methanol as a carbon source in chemical vapor deposition (CVD) graphene has an advantage over methane and hydrogen in that we can avoid optimizing an etching reagent condition. Since methanol itself can easily decompose into hydrocarbon and water (an etching reagent) at high temperatures [1], the pressure and the temperature of methanol are the only parameters we have to handle. In this study, synthetic conditions for highly crystalline and large area graphene have been optimized by adjusting pressure and temperature; the effect of each parameter was analyzed systematically by Raman, scanning electron microscope, transmission electron microscope, atomic force microscope, four-point-probe measurement, and UV-Vis. Defect density of graphene, represented by D/G ratio in Raman, decreased with increasing temperature and decreasing pressure; it negatively affected electrical conductivity. From our process and various analyses, methanol CVD growth for graphene has been found to be a safe, cheap, easy, and simple method to produce high quality, large area, and continuous graphene films.
        4,000원
        18.
        2012.06 구독 인증기관·개인회원 무료
        Chicken Insulin-like Growth Factor-1 (cIGF-1), one of the most important hormone for regulating physiological function includes body growth, muscle volume, bone density, chicken cell development and metabolism. In order to find in vitro Knokdown expression of cIGF-1, this study introduced tetracycline inducible RNA interference expression system (TetRNAi system). Tet system can inductively control high expression of extrinsic genes and expression of intrinsic genes. So it has advantages such as minimized physiological side-effects any cell and low cytotoxicity. RNAi system is proving to be a powerful experimental tool for inhibition of gene expression and post-transcriptional mechanism of gene silencing. RNAi is mediated by small interfering RNA (siRNA) consisting of 19- to 23- nucleotide double-stranded RNA duplexes that promote specific endonucleolytic cleavage of mRNA targets through an RNA-induced silencing. Then, this study RNAi-based gene knockdown can be achieved by retroviral-based expression systems. Stable integration of our inducible siRNA vector allowed the production of siRNA on doxycycline induction, followed by specific down regulation of chicken IGF-1 gene. Analyses of Real-time PCR to determine expression of the cIGF-1 gene showed successful from chicken embronic fibroblast (CEF) cells with the reduced rate of an approximately 92%. Our results demonstrate the successful regulation of cIGF-1 knockdown expression in CEF cells and support the application of an tetracycline inducible RNAi expression system in transgenic Mini chicken production. This research was supported by Bio-industry Technology Development Program, Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea.
        19.
        2011.10 구독 인증기관·개인회원 무료
        The leaf beetle, Chrysolina aurichalcea (Coleoptera: Chysomelidae), is a pest damaging plants of Compositae. In order to understand the genetic diversity and geographic variation we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) of the species collected from seven Korean localities. A total of 17 haplotypes (CACOI01 ~ CACOI17), with the maximum sequence divergence of 3.04% (20 bp) were obtained from COI gene sequence, whereas 16 sequence types (ITS2CA01 ~ ITS2CA16), with the maximum sequence divergence of 2.013% (9 bp) were obtained from ITS2, indicating substantially larger sequence divergence in COI gene sequence. Phylogenetically, the COI gene provided two haplotype groups with a high nodal support (≥ 87%), whereas ITS2 provided one sequence type group with a high nodal support (≥ 92%). The result of COI gene may suggest the presence of historical biogeographic barriers that bolster genetic subdivision in the species. Different grouping pattern between COI gene and ITS2 sequences were interpreted in terms of recent dispersal, reflected in the ITS2 sequence. Finally, finding of unique haplotypes and sequence types only from Beakryeng-Islet population was interpreted as an intact remnant of ancient polymorphism. As more samples are analyzed using further hyper-variable marker, further fruitful inference on the geographic contour of the species might be available.
        20.
        2011.05 구독 인증기관·개인회원 무료
        The leaf beetle, Chrysolina aurichalcea (Coleoptera: Chysomelidae), is a pest damaging plants of Compositae. In order to understand the genetic diversity and geographic variation of the species we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) collected from seven Korean localities. A total of 18 haplotypes (BARCA01 ~ BARCA18), with the maximum sequence divergence of 3.04% (20 bp) were obtained from COI gene sequence, whereas 17 sequence types (ITS2CA01 ~ ITS2CA17), with the maximum sequence divergence of 2.013% (9 bp) were obtained from ITS2, indicating substantially larger sequence divergence in mitochondrial gene sequence. Phylogenetically, the mitochondrial DNA has shown several haplotypes formed independent groups with substantially high node support (≥ 90%), whereas no such grouping was evidenced for ITS2, indicating different behaviors of the two molecules. Such difference may reflect a diverse dynamics of the species such as biogeographic history, mating behaviors, and also possibly different mode of inheritance of the two molecules, but requires further scrutinized examination of the dataset. In terms of population genetic perspective, overall no population subdivision was detected from both molecules, except for locality 7 (Eocheong islet) from mitochondrial DNA. As more scrutinized analysis is performed, further fruitful inference on the geographic contour of the species might be available.
        1 2 3 4 5