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        104.
        2012.10 구독 인증기관·개인회원 무료
        The baculovirus expression system is one of the most popular methods used for the production of recombinant proteins but has several complex steps which have proved inherently difficult to meet a multi-parellel process. We have developed a novel recombinant bacmid, bEasyBm that enabling easy and fast generation of pure recombinant virus without any purification step. In the bEasyBm, attR recombination sites were introduced to facilitate the generation of recombinant viral genome by in vitro transposition. Moreover, extracellular RNase gene from bacillus amyloliquefaciens, barnase, was expressed under the control of Cotesia plutellae bracovirus early promoter. Therefore, only when the barnase gene was replaced to gene of interest, the bEasyBm could replicate in host insect cells. When the bEasyBm was transposed with pDualBac-EGFP and pDualBac-LUC respectively, there were no non-recombinant backgrounds were detected from unpurified BmEasy-EGFP or BmEasy-LUC stocks. In addition, the resulting recombinant virus, BmEasy-EGFP, showed comparable level of EGFP expression efficiency with the plaque-purified recombinant virus, BmEGFP, which was constructed using bBmGOZA system. Based on these results, high-throughput condition for generation of multiple recombinant viruses in a time was established.
        105.
        2012.10 구독 인증기관·개인회원 무료
        Vector-borne plant virus transmission is a complex mechanism involving various interactions of viruses, vectors and plants. Plant viruses modify, either directly or indirectly, the rates of development, reproduction and behavior of vector insects in a positive, negative, or neutral manner. The sweetpotato whitefly, Bemisia tabaci, is the only known vector of Tomato Yellow Leaf Curl Virus (TYLCV) which is a virus that seriously damaged tomato cultivars all around the world. Acquisition of TYLCV influences on various developmental, physiological and molecular mechanisms of Q1 biotype B. tabaci. We compared several behavioral and physiological characteristics between non-viruliferous (NV) and TYLCV-viruliferous (V) of Q1 biotype whiteflies. When B. tabaci acquired TYLCV, total life span was shorter and fecundity was lower than NV ones. V whiteflies were more susceptible to thermal stress by increasing hsp mRNA levels but higher in mortality by either heat or cold shocks. Furthermore, V whiteflies increased the rates of plant sap probing and light attraction behaviors than NV ones. All together, our results show that TYLCV acquisition regulates B. tabaci to enhance the rates of development and environmental susceptibility. Our results provide insights to understand vector’s role in relation to the acquisition and transmission of plant viruses.
        106.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        플라스틱 사출 제품은 다양한 가전제품과 하이테크 제품에 널리 사용되고 있다. 그러나 현재의 치열한 경쟁적 비즈니스 환경에서 플라스틱 사출 제품 제조업자들은 고객을 만족시키면서 경쟁력을 얻기 위하여 다른 경쟁자들보다 먼저 새로운 제품을 시장에 출시하고 신제품의 개발기간을 줄이기 위한 노력을 할 여유가 부족하다. 따라서 무한경쟁의 시장에서 살아남기 위해서는 제조업자들은 시장 마켓 점유를 빠르게 올리는 것과 동시에 제품의 가격 경쟁력을 가져야 한다. 특징기반
        4,000원
        107.
        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.
        108.
        2012.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study we apply Support Vector Machine (SVM) to the prediction of geo-effective halo coronal mass ejections (CMEs). The SVM, which is one of machine learning algorithms, is used for the purpose of classification and regression analysis. We use halo and partial halo CMEs from January 1996 to April 2010 in the SOHO/LASCO CME Catalog for training and prediction. And we also use their associated X-ray flare classes to identify front-side halo CMEs (stronger than B1 class), and the Dst index to determine geo-effective halo CMEs (stronger than -50 nT). The combinations of the speed and the angular width of CMEs, and their associated X-ray classes are used for input features of the SVM. We make an attempt to find the best model by using cross-validation which is processed by changing kernel functions of the SVM and their parameters. As a result we obtain statistical parameters for the best model by using the speed of CME and its associated X-ray flare class as input features of the SVM: Accuracy=0.66, PODy=0.76, PODn=0.49, FAR=0.72, Bias=1.06, CSI=0.59, TSS=0.25. The performance of the statistical parameters by applying the SVM is much better than those from the simple classifications based on constant classifiers.
        4,000원
        109.
        2011.12 구독 인증기관 무료, 개인회원 유료
        Induced pluripotent stem (iPS) cells have been generated from mouse and human somatic cells by etopic expression of transcription factors. iPS cells are indistinguishable from ES cells in terms of morphology and stem cell marker expression. Moreover, mouse iPS cells give rise to chimeric mice that are competent for germline transmission. However, mice derived from iPS cells often develop tumors. Furthermore, the low efficiency of iPS cell generation is a big disadvantage for mechanistic studies. Nonviral plasmid‐based vectors are free of many of the drawbacks that constrain viral vectors. The histone deacetylase inhibitor valproic acid (VPA) has been shown to improve the efficiency of mouse and human iPS cell generation, and vitamin C (Vc) accelerates gene expression changes and establishment of the fully reprogrammed state. The MEK inhibitor PD0325901 (Stemgent) has been shown to increase the efficiency of the reprogramming of human primary fibroblasts into iPS cells. In this report, we described the generation of mouse iPS cells devoid of exogenous DNA by the simple transient transfection of a nonviral vector carrying 2A‐peptide‐linked reprogramming factors. We used VPA, Vc, and the MEK inhibitor PD0325901 to increase the reprogramming efficiency. The reprogrammed somatic cells expressed pluripotency markers and formed EBs.
        4,000원
        110.
        2011.09 구독 인증기관 무료, 개인회원 유료
        Human growth hormone (hGH), one of the most important hormones in medicine, is secreted from anterior pituitary gland. Its broad physiological function includes body growth, cell regeneration, increasement of muscle volume, bone density, body fat reduction, and so on. Due to the wide range of therapeutic effects, the hGH produced from E. coli has been commercialized already. In this study, we asked whether it is possible to produce recombinant hGH efficiently from various cultured mammalian cells. To meet this purpose, we chose a retrovirus vector system for transfer and expression of the hGH gene in various mammalian cells. Analyses of RT-PCR, ELISA, and Western blot to determine expression of the hGH gene showed the highest production of the hGH was determined from chicken embronic fibroblast (CEF) cells with the concentration of 8.58 μg/ml. The biological activity of the hGH was similar to the commercially available counterpart. These results suggest that mass production of hGH is possible not only in the E. coli but also in the various mammalian cells.
        4,000원
        111.
        2011.05 구독 인증기관·개인회원 무료
        Pine wilt disease, caused by pine wood nematode, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle, has become the most serious threat to pine trees in Korea since first reported in 1988. Pine wood nematode is transferred to uninfested trees by Monochamus alternatus (Coleoptera: Cerambycidae) (vector). A typical controlling method against vectors in Korea is fumigation of the dead trees infested by vector M.alternatus and B.xylophilus using metam-sodium SL(25%). However, this method is harmful to the environment because of the chemical contamination and vinyl waste in the mountain afterward. Portable Bark Remover (PBR) was contrived to reduce these environmental problems. The vectors oviposite under the bark of the freshly dead trees only. Debark infested trees prohibited the vectors from oviposite and finally, vectors can not complete their life cycle. The PBR is a newly designed as a debarking device that is equipped on top of the chain saw engine allowing ease and rapid debarking of the infested trees at the controlling field. Debarking of freshly-dead trees can eliminate egg-laying and hatch places where between the wood and bark from vectors. The new method for vector controlling using the debarking device is expected to lower-price and high-efficiency comparing with other conventional methods such as “crushing”, “burning” and “fumigation”.
        112.
        2011.03 구독 인증기관 무료, 개인회원 유료
        hFSH is a glycoprotein secreted from anterior pituitary and consists of α and β subunits. Because of its major biological functions including sperm formation in the male and for follicular growth, FSH is used to cure woman's sterility. In this study we tried to produce recombinant hFSH in vitro using a retrovirus expression vector. Two major components of the vector we constructed are: (ⅰ) a DNA fragment containing α and β genes fused by a DNA sequence coding carboxyl terminal peptide (CTP) of human chorionic gonadotropin, (ⅱ) a DNA fragment corresponding woodchuck hepatitis virus posttranscriptional regulatory element (WPRE). Evaluation of expression profile of the recombinant FSH using reverse transcription PCR and enzyme-linked immunosorbent assay (ELISA). Among three cell lines tested, HeLa cells were the best for hFSH expression (5,395 mIU/ml), then followed by chicken embryonic fibroblast (CEF) cells and Chinese hamster ovary (CHO) cells in the order of hFSH production. In addition to the amount, the FSH produced from HeLa cells was highest in terms of biological activity which was determined by measuring cAMP.
        4,000원
        113.
        2010.10 구독 인증기관·개인회원 무료
        There is a critical need for research and developmentin the area of correlation between the climatic change and vector-born diseases in terms of global point of view. The statistics (1907~2000) for about a century showed the average temperature in Korea was increased to 1.5℃, twice higher than that of global average (0.74℃). The average precipitation for the past decade also showed 10% increase per year up to 1,485.7mm. The A1B scenario of NIMR reported the future estimate of average temperature at the end of this century (21 C) would be increased to 4.0℃ compared with that of years (1971~2000). There appeared close correlation between the breeding disease vector populations and climatic change, even though the occurrence pattern of diseases transmitted by insect vectors and/or reservoir animals in Korea had been rather included in category of the developed countries till 20th century. However, the disease outbreaks for the past 10 years showed significant increase in the vector-born diseases such as Tsutsugamushi disease, Leptospirosis and Epidemic Hemorrhagic fever. There appeared many different factors involved in causing foregoing disease increase, however, the warmer temperature change might have accelerated the more favorable breeding habitats for the disease vectors and medically important insects. The insect-born disease transmission inclusive of medically important insects and rodents involves wide range of different and/or compounded factors or situations such as human population and housing habitats, sanitary standards, vector control schedules, etc. in different areas and districts. Duane, et al.(2001) reported and well illustrated the correlations among climatic change and humans host, insect vectors, reservoir animals, disease agents. The importance of local outbreaks of insect vector population increase was mainly caused by temperature and precipitation (humidity) increase (Mellor and Leake, 2000) by the increase of fecundity and frequency of biting activities. Martens (2008) also indicated that climatic change affected the increases of survival rate, density, fecundity duration and the resistance to microbial pesticides more favorably against disease agents such as bacteria and fungi, etc. The influences or effects of climatic change against human pest control activities, susceptibility, immunity to insect vector-born diseases will be elaborated.
        114.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sea surface wind field was retrieved from high-resolution SIR-C SAR data by using CMOD algorithms off the east coast of Korea. In order to extract wind direction information from SAR data, a two-dimensional spectral analysis method was applied to the normalized radar cross section of the image. An 180˚-ambiguity problem in the determination of wind direction was solved by selecting a direction nearest to the wind vector of the ECMWF reanalysis data. Comparison of the wind retrieval patterns with the ECMWF and NCEP/NCAR dataset showed RMS errors in the range of 1.30 to 1.72 ms-1. In contrast, comparison of wind directions revealed large errors of greater than 60˚, which is enormously higher than the permitted limit of about 20˚ for satellite scatterometer winds. Compared with wind speed results from different algorithms, wind vectors based on commonly-used CMOD4 algorithm showed good agreement with those derived by other algorithms such as CMODIFR2 and CMOD5, particularly at medium winds from 4 to 8 ms-1. However, apparent discrepancy appeared at low winds (〈 4 ms-1). This study also addressed an importance of accurate wind direction data to improve the accuracy of wind speed retrieval and discussed potential causes of wind retrieval errors from SAR data.
        4,500원
        115.
        2010.09 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to establish a basic culture system enabling in vitro culture of chicken blastodermal cells and to test the feasibility of retrovirus-mediated gene transfer to the cultured cells. The blastodermal cells were isolated from freshly laid eggs of stage X and cultured with or without STO feeder layer cells. Stem cell-like morphology was maintained after multiple passages and RT-PCR analysis proved expression of several stem cell specific genes. Immunocytochemical analysis using antibodies of anti-EMA-1 and anti-SSEA-1 also showed the feature of stem cells. Infection of the cultured blastodermal cells with LNCGW retrovirus vector resulted in successful transfer of foreign genes. The results of this study may be useful in establishing stem cell-mediated transgenic chicken production.
        4,000원
        118.
        2010.05 구독 인증기관·개인회원 무료
        Density of malaria vector mosquito was monitored at 24 sites in Korea to estimate malaria epidemic from 2004 to 2009. Twenty four locations include six in Gwangwon province and nine in Kyonggi province and nine in Incheon metropolitan city. Mosquitoes collected by public health centers in 24 sites were sent to each RIPHE(Research Institute of Public Health & Environment) then the RIPHE identified the malaria vector mosquitoes. KCDC analysed the results. Number of malaria vector mosquito collected in 2009 shapely decreased over 33 % when compared with number of mosquito collected from 2004 to 2009. In 2009, malaria vector mosquitoes firstly were collected at Injegun on 2nd week of April (6-13, April) and the highest peak of collected mosquito was demonstrated on 3rd week of August. Number of collected mosquito sharply decreased below 10 at 3rd week of september and None of mosquito was collected 2nd week October. Decrease of number of malaria vector mosquito collected in 2009 seem to be related with lowest temperature around midnight and precipitation days per month.
        119.
        2010.05 구독 인증기관·개인회원 무료
        In many cases over the years, we failed to forecast accurately outbreak of Rice stripe virus (RSV) disease using population density of overwintering small brown planthopper (SBPH), Laodelphax striatellus. What is the source of error in this viral disease assessment? For answering the question, spatial distribution of RSV in paddy fields was investigated in relation to the yield of rice grain, and the population density of overwintering SBPH in ridge of paddy fields. Total 14 paddy fields in 5 regions were surveyed in June, 2008. Disease assessment was carried out with each of 30 rice plants in the one of the borders, 5th, 10th line from ridge, and 90 rice plants in diagonal line for conventional method. The ears of rices from 18 plants in the same surveyed line were collected in the late of August for the weights of 100 rice grains. The infection rate of RSV was decreased by the distance from ridge; on the contrary, the increase tendency was shown in the yield of rice grains in the middle of paddy field. It is suggested that the border effect of viral distribution between ridge and paddy field is caused by the spatial distribution of the vector insect. Thus, in this case, the narrow border effect could represent that the SBPH migrated short distance from the ridge to paddy field. The conventional method, observing the disease in middle area of diagonal line, showed no correlation to the population density of overwintering vector generation in ridge. It might cause underestimation of the regional disease rate. The counting of RSV-diseased plant in border line only overestimated it also. However, the RSV infection rate in the near border had highly positive linear relationship (R2=0.91) to the regional average values by regression analysis. Therefore, the near border sampling method can improve the RSV disease risk assessment.
        120.
        2009.10 구독 인증기관·개인회원 무료
        The small brown planthopper (SBPH), Laodelphax striatelleus (Fallén), is a insect vector of Rice stripe virus (RSV) in temperate countries such as Korea, Japan, China, and Taiwan. As SBPH is able to overwinter successfully in these areas, RSV disease in subsequent rice fields has been believed to be endemic. In Korea, however, the RSV disease outbreaks have been observed mainly but not continuously at some western regions since 2001, caused a severe damage to the rice production. Although many efforts are underway to explain the outbreak phenomenon, the exact related factors are not known yet. In the meantime of the study on SBPH population dynamics in 2009, we catched unusually large numbers of SBPH adults by aerial net traps, maximally over 900, in early June at western coastal counties such as Taean, Seocheon, Buan, Sinan, and Jindo in Korea. Age distribution changes of SBPH in winter and post-winter seasons at some selected fields shows that the adults might be not related to overwintering population. The adults of overwintering population emerged from early April. Newly hatched nymphs of first generation were found from mid-May. In late May, just before the unusual catch of adults, the developmental stages of SBPH were mostly below 5th instars. This means that the big adult populations would be results of mass migration of SBPH abroad. We present also spacial distribution and host relationship of overwintering population as well as viruliferous rate changes of immigratory population.