검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 2,998

        1621.
        2012.06 구독 인증기관·개인회원 무료
        The objective of this study was to investigate the proteome composition in pretermand term‐derived human umbilical cord. Umbilical cord samples were collected from 6 preterm infants with gestational age less than 36 weeks or 4 full terms together with medical information during prenatal period. Several biomarkers are routinely used clinically for predicting preterm labor; however, these factors are either nonspecific or detected too late. Protein profiles were performed on samples from both preterm‐ and termderived human umbilical cord by using Two‐dimensional gel electrophoresis (2‐DE). Approximately 200 different proteins were identified between preterm‐ and term‐delivered umbilical cords. Among them, differentially expressed 34 proteins were identified in 48 protein spots. In the preterm‐derived human umbilical cords, 15 proteins were present at higher levels (2.0‐ to 9.28‐fold increases) and 19 were present at lower levels (2.0‐ to 11.8‐ fold decreases or not detectable) compared to the control term‐derived umbilical cords. Proteomics approaches such as 2‐DE could greatly facilitate the discovery of new and better biomarkers. The high sensitivity and specificity achieved by the combined use of the selected biomarkers show great potential for the early detection of Adverse pregnancy outcomes such as pre‐eclampsia, small for gestational age infants, preterm delivery and placental abruption are associated with higher mortality. Increased amount of HIF‐1 α, GAPDH and HSP27 were observed in preterm‐derived umbilical cords was due to hypoxia‐ dependant and oxidative stress‐independent manner. Moreover, we isolated HUVEC (Human umbilical vascular endothelial cells) from preterm‐ and term‐derived umbilical cords and examined LDH activity. The results of the current study may provide important insights into the molecular mechanisms underlying umbilical cord development and also these data will contribute to a better understanding of the composition of preterm‐ and term ‐ derived human umbilical cord and aid the discovery of novel biomarkers for the prenatal diagnosis of fetal abnormalities
        1622.
        2012.06 구독 인증기관·개인회원 무료
        Light-emitting diodes are used in applications as diverse as aviation lighting, automotive lighting, advertising, general lighting, and traffic signals. LED panel light source used in an experiment on plant and mushroom growth. To establish the optimum artificial light illumination method for Pleurotus eryngii in closed mushroom factory system, the effects of red LED light quality on growth was investigated. The humidity was maintained more than 90% and temperature was 15~16℃, and CO2 density was 500ppm. The fresh weightand height were higher under red LED light (650nm, 73.1 Pmol/m 2s) comparing with control (fluorescent lamp, 10~20 lux). β-aminoisobutyric acid and total phenol content were higher under red LED light (650nm, 73.1 Pmol/m2s).
        1623.
        2012.05 구독 인증기관·개인회원 무료
        The resistance levels to carbamate (CB) and organophosphate (OP) insecticides were determined by topical application in 14 field strains of Nilaparvata lugens. The resistance levels to CB and OP were 1.3~47.5-fold and 1.4~14.4-fold higher than a susceptible strain, respectively. A quantitative sequencing (QS) protocol was established to determine the allele frequencies of four acetylcholinesterase point mutations putatively associated with CB and OP resistance. The allele frequencies of the four mutations (G119A, F/Y330S, F331H and I332L) in field strains ranged from ca. 0.0~51.7%, 0.0~88.9%, 2.5~47.7%, 5.1~56.0% and 6.7~57.3%, respectively. The F331H and I332L were tightly linked each other, suggesting these mutations may occur simultaneously. In the correlation analysis, G119A was not well correlated with actual resistance levels (r2= < 0.232), whereas F331H and I332L showed a better correlation with the resistance levels of benzofuranyl methylcarbamates (r2= 0.595). This finding indicates that F331H and I332L mutation frequencies may be used as molecular markers for detecting carbamate resistance in N. lugens. A QS protocol detecting the F331H and I332L mutation frequencies would be employed as a supportive tool for rapid monitoring of CB insecticide resistance levels in N. lugens
        1624.
        2012.05 구독 인증기관·개인회원 무료
        The screening of effective lethal genes was conducted via the systemic delivery of dsRNA for the RNA interference (RNAi)-based management of Tetranychus urticae. Four candidate genes (coatomer protein complex, T-COP; M1 metalloprotease, T-M1MP; Ribosomal protein S4, T-RPS4; A subunit of V-ATPase, T-VATPase) with a reference genes (EGFP) were tested for the experiment. Translocated dsRNA to the leaf disc (ca. 30 mm diameter) was detected at 12 h post-treatment, indicating that dsRNA could move through leaf veins. In the evaluation of mortality, the T-COP, T-RPS4 and T-VATPase exerted moderate levels of toxicity at 72 h post-treatment among four dsRNA tested. Knockdown of the target genes were confirmed by quantitative PCR, suggesting that RNAi of target genes was accomplished by feeding dsRNA. In summary, the dsRNA delivery via leaf disc was effective in screening lethal genes, and some genes, such as T-COP, T-M1MP, T-RPS4 and T-VATPase, can be applicable for establishing a RNAi-based control system against T. urticae.
        1625.
        2012.05 구독 인증기관·개인회원 무료
        We analyzed molecular and enzymatic properties of three cholinesterases (ChEs; ClAChE1, ClAChE2 and ClSChE) from Cimex lectularius. The ClAChE1 and ClAChE2 were generally present as a membrane-anchored dimeric insoluble form in the brain and ganglia. In the case of ClSChE, monomeric and dimeric soluble forms were observed. To investigate enzymatic properties, three ChEs were functionally expressed using baculovirus expression system. ClAChE1 revealed a significantly higher activity than ClAChE2 to acetylthiocholine iodide (ATChI) substrate. Kinetic analysis using two choline substrates (ATChI and butyrylthiocholine iodide) demonstrated that ClAChE2 had higher catalytic efficiency but lower substrate specificity than ClAChE1. Inhibition assay was conducted by using three inhibitors (BW284C51, eserine, Iso-OMPA) and two insecticides (chlorpyrifos-methyl and carbaryl). Two ClAChEs revealed high sensitivities to BW284C51, eserine, chlorpyrifos-methyl and carbaryl, but were not sensitive to Iso-OMPA. This inhibition profile confirmed that both ClAChEs are categorized as ChEs. Interestingly, the salivary specific cholinesterase did not show any measurable activities to choline substrates, confirming its non-synaptic function in C. lectularius
        1626.
        2012.05 구독 인증기관·개인회원 무료
        Metcalfa pruinosa (Say), native to North America, is spreading rapidly in the Korean Peninsula, causing serious damages on many deciduous forest trees, ornamental trees, and agricultural crops. Before the first report from Korea in 2005, M. pruinosa has not been reported from any other countries in the Eastern Palaearctic, while it has been record in Italy in 1979, and rapidly spreading into many European countries. To trace the invasion route of this species, we analyzed haplotype analysis of the mitochondrial cytochrome c oxidase subunit-I (mtCOI, 577bp), and developed microsatellite markers. In the haplotype analysis, a total of fourteen haplotypes were found from 69 individuals in 18 populations: 12 haplotypes (native region), 4 haplotypes (European region) and 2 haplotypes (Korea). Interestingly, Korean populations were clustered with some European populations. Eight polymorphic microsatellite loci were developed, and population structures were analyzed from 145 individuals in 8 populations. The origin and invasion route of M. pruinosa are under investigation.
        1630.
        2012.04 구독 인증기관·개인회원 무료
        1631.
        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
        1632.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we describe the installation of VLBI Correlation Subsystem (VCS) main product and its performance at the Korea-Japan Correlation Center (KJCC). The VCS main product was installed at KJCC in August 2009. For the overall performance evaluation of VCS, playbacks, Raw VLBI Data Buffer (RVDB) system, and Data Archive (DA) system were installed together. The VCS main product was connected between RVDB and DA, and the correlation results were put into the DA to confirm the normal operation of VCS 16 station mode configuration. The evaluation test was first performed with 4 station mode, same as the factory test of VCS main product. Based on the results of 4 station mode, the same evaluation test was conducted for 16 station mode of VCS. We found that the correlation results of VCS were almost similarly compared to those of the Mitaka FX Correlator. Through the test results, we confirmed that the problems such as spectrum errors, delay parameter processing module and field programmable gate array errors in antenna unit, which were generated at the factory test of VCS main product, were clearly solved. And we verified the performance and connectivity of VCS by obtaining the expected correlation results and we also confirmed that the performance of VCS was sufficient for real VLBI observation data in both 4 and 16 station modes.
        4,900원
        1633.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 시험에서 건초(티머시, 알팔파 및 클라인)와 짚류(톨페스큐 및 볏짚)의 buffer 용해도와 단백질 분획이 실시되었으며, 조사료 자원의 buffer 추출이 in vitro 발효 성상, 분해율 및가스(CO2 및 CH4) 생성량에 미치는 효과를 조사하였다. 다른 조사료에 비해 총 단백질 중buffer 가용성 조단백질과 A fraction은 알팔파건초에서 각각 61% 및 41.77%로 가장 높았으며 볏짚에서 가장 낮았다(각각 42.8% 및19.78%). 총단백질 중 B1 fraction은 조사된 조사료간 비교적 큰 차이를 보이지 않았으나 B2fraction에서는 다른 조사료(6.34~8.85%)에 비하여 톨페스큐짚(10.05%) 및 클라인 건초(12.34)%에서 다소 높은 수준을 보였다. 총 단백질 중B3 fraction이 차지하는 비율은 톨페스큐짚에서38.49%로 가장 높았으나 다른 조사료 자원 간에는 큰 차이가 없었으며, C fraction의 경우 볏짚에서 가장 높은 비율(15.05%)을 보였다. 모든 사료에서 배양 개시 후 3시간(P<0.01) 및 6시간(P<0.05)에서 buffer 추출 전에 비해 추출후 배양액의 pH가 증가되었으며, 배양 6시간(P<0.05) 및 12시간(P<0.001)에서 다른 사료에비해 티모시 건초 및 알팔파 건초로부터의 pH가 낮았다. 배양액의 암모니아 농도는 모든 배양시간에서 가용성 물질의 추출 전 후에 다른조사료에 비해 알팔파 건초에서 가장 높았으나모든 사료의 추출효과는 배양 3시간(P<0.01)에서만 나타났다. 배양액의 총 VFA 농도는 배양24시간까지 알팔파 건초에서 가장 높았던 반면톨페스큐짚과 볏짚에서 가장 낮았다. 또한 모든 조사료에서 buffer 추출 전에 비하여 추출후에 총 VFA 농도가 감소되었다(P<0.01~P<0.001). Acetic acid (C2)의 조성 비율에서는 배양 6시간까지 추출 전에 더 높았으나(P<0.001)사료 간 차이는 없었다. Propionic acid (C3) 조성 비율 역시 배양 개시 후 3, 24 및 48시간(P<0.001)에 추출 전에 더 높았으며, 6 및 12시간의 배양액에서 대부분 건초(티모시, 알팔파 및 클라인)와 짚류(톨페스큐짚 및 볏짚) 간차이가 있는 것으로 조사되었다(P<0.05). 그러나 butyric acid (C4) 조성비율의 경우 대부분의배양시간에서 사료 간 차이는 없었다. 건물에서의 분해율 관련 parameter 중 a 값은 조사된전체 조사료에서 buffer 추출 전이 추출 후에비해서 높았으며(P<0.001), 다른 조사료에 비해톨페스큐짚과 볏짚에서 크게 낮았다(P<0.05).또한 b 값의 경우 역시 추출 전에 비해 추출후에서 현저히 낮았으나(P<0.001) 사료 간 차이는 없었다. 볏짚을 제외한 조사료에서 추출후에 비해 추출 전의 건물 유효분해율(EDDM)이 더 높았다(P<0.001). 조단백질에서의 a, b및 c 값은 추출 전에 비해 추출 후에서 현저히낮았으나(P<0.05) 사료 간 차이는 없었다. 조단백질 유효분해율(EDCP)에서는 다른 조사료 종류에 비해 톨페스큐짚과 볏짚에서 낮았다(P<0.05). 한편, NDF의 경우 a 값과 b 값(P<0.01)및 NDF 유효분해율(EDNDF, P<0.001)은 추출후에 비해 추출 전에 더 높았으나(P<0.01) 사료 간 차이는 보이지 않았다. 반추위미생물에의해 사료분해과정 중 생성되는 CO2 량도 24시간 배양까지는 추출 전에 더 많았으며(P<0.05~P<0.001), 톨페스큐짚과 볏짚에 비해 건초형태의 조사료로부터의 CO2 생성량이 더 많았다(P<0.05~P<0.01). 메탄가스(CH4) 생성량 역시 모든 배양시간에서 추출 전에 비해 추출 후에 크게 감소되었으며(P<0.01~P<0.001), 12~24시간을 제외하고는 짚류에 비해 건초에서 현저히 높은(P<0.05) 것으로 나타났다. 본 시험의 결과를 종합하면, 조사료 자원에 대한 buffer용해도와 단백질의 분획이 in vitro VFA 농도와 분해율 및 gas (CO2 및 CH4) 발생량 간 상호 밀접한 관계를 보이는 것으로 여겨진다. 이에 따라 조사료 이용 효율 개선을 위해 조사료자원에 대한 buffer 용해도와 단백질 분획을 반추동물 TMR 조제에 활용할 필요가 있는 것으로 여겨진다.
        4,900원
        1634.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A study was conducted on four crossbred bulls, used as artificial insemination (AI) sires, to correlate their semen quality with their non return rate (NRR). Semen was collected once a week via an artificial vagina, diluted in egg yolk-citrate and maintained at for three days. It was evaluated for sperm motility, viability, morphology immediately after collection and was examined daily for sperm motility, viability and morphology of acrosome, mid piece and tail for a total of three days. A total of 2016 cows were inseminated by two AI technicians. The proportions of sperm with normal heads were 83.4% (63.7~91.7%), the proportion of spermatozoa exhibiting normal morphology (acrosome, mid piece and tail), motility and viability were 89.2% (82.3~92.0%), 71.3% (61.7~75.0%) and 76.7% (65.7~85.0%), respectively in fresh ejaculates. Sperm motility and sperm viability was significantly ( <0.05) lower in Holstein-Friesian Local bull than in other bulls during all three days of storage. The overall NRR for four bulls was 82.7% (72.9-87.5%). Bulls with higher sperm motility, viability and normal morphology of spermatozoa of individual bull had significantly (each <0.05) higher NRR. The highest ( <0.01) NRR (87.5%) was observed in a Red Chittagong bull whose semen qualities were significantly ( <0.05) higher than Holstein-Friesian Local bull (NNR 72.9%). The results of the present study concluded that NRR at 56 days post AI is related to parameters of semen quality. Therefore, semen evaluation may allow the discarding of bulls with poor fertility in an AI program.
        4,000원
        1635.
        2012.03 구독 인증기관 무료, 개인회원 유료
        Cytokines are known to function as regulatory molecules that can be produced by virtually every nucleated cell type in the body, including lymphocytes, monocytes/macrophages, epithelial cells, fibroblasts, and many others. Cytokines include lymphocyte-derived factors (lymphokines), monocyte-derived factors (monokines), hematopoietic factors (colony-stimulating factors), connective tissue/ growth factors, and chemotactic chemokines. Cytokines released in response to infection can affect tumor development in different ways. When exposed to infectious agents, cytokines are secreted by sentinel cells, such as macrophages and dendritic cells. These cytokines include interleukin 1 (IL-1) and tumor necrosis factor-α, as well as others, such as IL-6, IL-12, and IL-18. When released in sufficient quantities, these molecules can cause inflammation. Chronic inflammation is highly associated with tumor initiation, promotion, and progression. In this article, we review the roles and mechanisms of cytokines in tumor development.
        4,300원
        1636.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Tungsten nanopowders were produced by the method of wires electrical explosion in the different gases. The study of phase and dispersed composition of the powders was carried out. The influence of electrical parameters such as the value of energy input in wire and the arc stage of the explosion was discussed. The factors that make for decreasing the particles size are the lower pressure of surrounding gas and the use of addition of chemically reactive gas.
        4,000원
        1637.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The current situation of the nanopowders production technology based on the process of electrical explosion of wires is described. The advantages and disadvantages of the electroexplosive technology are indicated. The results of studies characterizing the effect of the electrical explosion conditions on the nanopowders properties are presented, including latest results: conditions of nanopowders passivation, conditions of nanopowders production having narrow size distribution, the methods of nanopowders diagnostic and standartization. In addition, the application and area of future research on this technology are proposed.
        4,000원
        1638.
        2012.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Microthermal fluctuations are introduced by atmospheric turbulence very near the ground. In order to detect microthermal fluctuations at Fuxian Solar Observatory (FSO), a microthermal instrument has been developed. The microthermal instrument consists of a microthermal sensor, which is based on a Wheatstone bridge circuit and uses fine tungsten filaments as resistance temperature detectors, an associated signal processing unit, and a data collection, & communication subsystem. In this paper, after a brief introduction to surface layer seeing, we discuss the instrumentation behind the microthermal detector we have developed and then present the results obtained. The results of the evaluation indicate that the effect of the turbulent surface boundary layer to astronomical seeing would become sufficiently small when installing a telescope at a height of 16m or higher from the ground at FSO.
        4,000원
        1639.
        2012.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We use a Probabilistic Neural Network (PNN) technique to derive the orbital parameters of spec- troscopic binary stars. Using measured radial velocity data of five double-lined spectroscopic binary systems (i.e., EQ Tau, V376 And, V776 Cas, V2377 Oph and EE Cet), we find the corresponding orbital and spectroscopic elements. Our numerical results are in good agreement with those obtained by other groups via more traditional methods.
        4,000원
        1640.
        2011.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this paper, the long-term hemispheric variation of the polar faculae is investigated. It is found that, (1) both the N-S asymmetry and N-S asynchrony of the polar faculae exhibit a long-term persistence, which suggests that they should not be regarded as a stochastic phenomenon; (2) both the N-S asynchrony and N-S asymmetry of the polar faculae are functions of the latitude, implying that the N-S asynchrony of the polar faculae is related to the N-S asymmetry of the polar faculae; (3) from a long-term view, the dominant hemisphere of the polar faculae seems to have close connection with the phase-leading hemisphere of the polar faculae.
        4,000원