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        검색결과 276

        41.
        2019.04 구독 인증기관·개인회원 무료
        The red imported fire ant (RIFA, Solenopsis invicta Buren) is defined as invasive species and one of 100 most threaten alien species in world by IUCN. In Korea, RIFA has been first detected at September 28th, 2017 in Busan Port during surveillance by Animal and Plant Quarantine Agency (APQA). The RIFA colony was revealed as a polygyne and H5 type through epidemiological analysis on Gp-9 gene and mt-DNA haplotype. APQA has developed eradication program for RIFA with enhanced surveillance in all nationwide Ports and Internal Container Depots. There are subsequently 7 times more invasions of RIFA in Ports (Busan, Pyongeaek, and Incheon) including 2 times of inlands (Daegu and Ansan) and completely eradicated so far. International trade and climate change increases possibility of establishment and spreading of RIFA in Korea. Therefore, it must be required an international cooperation for prevention of global spreading of RIFA between countries.
        42.
        2019.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the effectiveness of a multi-action hybrid damper (MHD) composed of lead rubber bearing (LRB) and friction pad was verified in terms of seismic performance improvement of a frame structure. The LRB and the friction elements are connected in series, so the LRB governs the intial small deformation and the friction determines large deformation behavior. Cyclic loading tests were conducted by using a half scale steel frame structure with the MHD, and the results indicated that the structure became to have the stable trilinear hysteresis with large initial stiffness and first yielding due to the LRB, and the second yielding due to the friction. The MHD could significantly increase the energy dissipation capacity of the structure and the hysteresis curves obtained by tests were almost identical to the analytically estimated ones.
        4,000원
        45.
        2018.10 구독 인증기관·개인회원 무료
        Haplodiploid sex determination is prevalent in nature comprising about 25% of higher taxa. Due to its uniqueness, selfish entity may relatively easily slip in the system. Here, I will introduce 3 different types of selfish entities. First, some microorganisms are known to distort sex ratio in favor of their own prosperity. Second, a genetic fragment, called paternal sex ratio chromosome, is classified as the extremely selfish element so far in haplodiploid. Finally, haploid genome itself can evolve selfishness. The first two result in skewed sex ratio, and the last in completely new genetic relatedness. I will also discuss their evolutionary significance and potential utilization in controlling pest populations.
        46.
        2018.10 구독 인증기관·개인회원 무료
        Herbicides have consistently contributed to yield increases in crop production for many decades however, those same herbicides are facing the loss of effectiveness because of the rapid spread of weed resistance. Since the first instance of herbicide resistance to triazine herbicides over 50 years ago, resistant biotypes have been observed to the major herbicides numbering more than 150 different weed species due to excessive use of single mode of action (MoA)treatments combined with limited crop rotation practices. In the US, the most well-known broad-spectrum herbicide used in major crops, glyphosate is facing huge challenges due to the appearance of many resistant weed species. The consequences of the loss of effectiveness of the current herbicide choices, coinciding with an increasing world population with improved living standards, is beginning to present a severe constraint on food security globally. Unfortunately, the agriculture industry has been unable to find any new mechanism in the last 30 years. The absence of choices of novel active ingredients along with the increased costs of developing new entities is forcing the industry to rely on older modes of action which, with limited application, means lower annual yields of the major crops as the number of resistant weed species increases. The Chemical Genomics group in FMC Agricultural Solutions Discovery has been building ‘Chemistry to Gene’ (C2G) capability to identify new MoAsby applying chemical genomics tools. We have recently discovered that compounds described in WO2017075559A1, are potent selective herbicides with novel action that control many grasses. As a result of knowledge of the mechanism of this area of chemistry, we have extended the work to include a ‘Gene to Chemistry’ (G2C) approach to provide new structural starting points for more synthesis projects.
        47.
        2018.10 구독 인증기관·개인회원 무료
        Growing resistance to insecticides, especially pyrethroids, poses an increased risk for insect control world-wide. Thus, alternative compounds are urgently needed. Accordingly, my laboratory has been investigating synthetic materials, as well as natural products, which are an attractive source of new chemistries. We have examined the insecticidal and synergistic activity of new compounds using Drosophila melanogaster and the mosquitoes Aedes aegypti and Anopheles gambiae as model insects. In addition, we have also been investigating the modes of action of experimental molecules in various physiological preparations. Natural product research included thymol, which was toxic to Ae. aegypti adults at doses (3-50 μg/mg) similar to published toxicities for the cabbage looper larvae, Trichoplusia ni. On homomultimeric Anopheles gambiae GABA receptor-chloride channel complex expressed in Xenopus laevis oocytes, thymol acts as a positive allosteric modulator, increasing the potency and maximal effectiveness of applied GABA, consistent with the sluggish paralysis it elicits in exposed insects. Other studies investigated matrine; a bioactive component extracted from Sophora flavescens that is used as the main ingredient in Chinese bio-pesticidal products. Matrine caused flaccid paralysis in headless fourth instar larvae of Ae. aegypti (50% paralysis in 5 hours at 8 ppm) and was toxic to adult females by contact (topical LD50 = 258 ng/mg). Adult toxicity was increased about 2-fold by pretreatment with the mono-oxygenase inhibitor, piperonyl butoxide. Interestingly, this compound was much less effective on D. melanogaster in either glass contact or feeding bioassays. Adult mosquito knockdown was rapid, with little or no expression of hyperactivity or hyperexcitability. Matrine (ca. 1 mM) had effects similar to thymol on expressed An. gambiae GABA receptors, and reduced EPSP amplitude at the Musca domestica neuromuscular junction, without any evidence of neuroexcitation or membrane depolarization. These physiological actions are sufficient to explain the whole animal intoxication by matrine, but require relatively high concentrations to manifest themselves. Other studies tested a series of potassium channel blockers, including 1-((2-chlorophenyl)diphenylmethyl)-1H-pyrazole (TRAM-34), 11-dansylaminoundecanoic acid (DAUDA), and 5-hydroxydecanoic acid (5-HDC) as insecticides and synergists of pyrethroids. We also evaluated the action of these compounds in patch clamp recordings of engineered HEK cells expressing Anopheles gambiae Kv2.1 channels. Patch clamp studies revealed that fatty acid compounds without functional groups in the alkyl chain (e.g., decanoate, DAUDA) yielded a more potent blocking action on Kv2.1 currents than substituted fatty acids (e.g., 5-HDC). Also, in comparison to 2-methoxy-N-((1-phenylcyclopentyl)methyl)benzamide (2S-65465), a known Kv2 channel blocker (IC50 = 100 nM), decanoate and DAUDA were 6-fold and 12-fold less active, respectively, as blockers of potassium current. TRAM-34 was the least potent inhibitor tested in patch clamp studies (IC50 = 30 uM). When tested on D. melanogaster CNS, the compounds typically gave an initial increase in firing rate, followed by a decrease, both effects at micromolar concentrations. Various toxicity assays showed the same potency ranking as that obtained through patch-clamp recordings, indicating a possible connection between channel block and whole organism effects. In order to possibly improve the insecticidal activity of the fatty acids, we synthesized derivatized analogs (e.g., methyl esters) presumed to better penetrate the cuticular barrier, but activity did not improve. Finally, in contrast to a published patent, we found that fatty acids did not show much synergism with pyrethroids. The implications of this work for resistance management will be discussed.
        48.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Humic substances that can be obtained from coal resources such as leonardite in a bulk scale have been employed as crop stimulators and soil conditioners. The polymeric organics containing a variety of aromatic and aliphatic structures are known to activate plants in a multifunctional way, thus resulting in enhanced germination rate and abiotic stress resistance concomitant with induction of numerous genes and proteins. Although detailed structural-functional relationship of humic substances for plant stimulations has not been deciphered yet, cutting-edge analytical tools have unraveled critical features of humic architectures that could be linked to the action mechanisms of their plant stimulations. In this review article, we introduce key findings of humic structures and related biological functions that boost plant growth and abiotic stress resistance. Oxygen-based functional groups and plant hormone-like structures combined with labile and recalcitrant carbon backbones are believed to be critical moieties to induce plant stimulations. Some proteins such as HIGH-AFFINITY K+ TRANSPORTER 1, phospholipase A2 and H+-ATPase have been also recognized as key players that could be critically involved in humic substance-driven changes in plant physiology.
        4,000원
        49.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        울금(Curcuma longa L.)의 사포닌 함량과, 증류수(distilled water, DW), 70% 에탄올 및 노르말 부탄올의 3가지 용매를 사용하여 산화억제 효과를 통한 기능성 식품 소재로서의 가치를 확인한 결과, 총 사포닌 함량은 7.506±0.349 mg SE/g dry weight으로 확인되었다. 추출 수율은 DW (17.11%), 70% 에탄올(15.26%), 노르말 부탄올(4.12%)로 DW에서 가장 높게 나타났으며, 노르말 부탄올 추출물에서 낮은 수율을 보였다. 항산화 활성은 농도가 높아질수록 활성이 증가되는 것으로 관찰되었다. 총 페놀 함량은 DW, 70% 에탄올, 노르말 부탄올 순으로 각각 8.57, 41.01, 119.11 mg GAE/g의 함량으로 나타났으며, 노르말 부탄올 추출물에서 유의적인 차이를 보이며 높게 관찰되었다(p<0.05). DPPH 라디칼 소거활성은 DW, 70% 에탄올, 노르말 부탄올 순으로 확인되었다. ABTS 라디칼 소거활성, 환원력 및 ferric reducing antioxidant power (FRAP) 또한 DPPH 라디칼 소거활성과 비슷한 양상으로 나타났지만, ferrous ion 킬레이트 능은 노르말 부탄올(15.87~21.17%), 70% 에탄올(26.10~50.76%), DW(44.47~84.24%) 순으로 측정되었다. 이에, 울금은 산화억제 및 생리활성을 가지는 것으로 규명되었으며 기능성 식품 소재로서의 활용 가능성이 높은 것으로 사료된다.
        4,200원
        50.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 급성기 뇌졸중 환자에서 동작관찰 체간훈련이 체간조절능력, 균형, 일상생활수행능력에 미치는 효과를 알아보고자 실시하였다. 연구방법 : 2017년 7월 3일부터 2018년 4월 30일까지 전북 익산 소재의 W 대학병원에 입원한 급성기 뇌졸중 환자 14명을 실험군과 대조군으로 무작위 할당하였다. 두 군 모두 일반적인 물리·작업치료를 실시하였다. 추가적으로 실험군에는 동작관찰 체간훈련을, 대조군은 풍경관찰 체간훈련을 각 1일 1회 30 분, 주 5회, 총 3주간 실시하였다. 치료 중재 전·후 체간조절능력을 측정하기 위해 체간 손상 척도 (Trunk Impairment Scale; TIS), 균형능력을 측정하기 위해 수정된 기능적 팔 뻗기 검사(Modified Functional Reach Test; M-FRT)와 버그균형척도(Berg Balance Scale; BBS)를 사용하였고, 일상생활활동 수행능력을 평가하기 위해 한국판 수정된 바델 지수(Korean version of Modified Barthel Index; K-MBI)을 사용하였다. 결과 : 3주 중재 후, 두 그룹에서 중재 전·후 체간조절능력, 균형, 일상생활수행능력에서 유의한 차이가 나타났으며 (p<.05), 중재 후 두 그룹 간 변화량의 차이는 TIS와 M-FRT에서 유의한 차이가 나타났다(p<.05). 결론 : 본 연구 결과 동작관찰 체간훈련이 급성기 뇌줄중 환자의 체간조절능력, 균형, 일상생활수행능력을 향상시킬 수 있는 중재 방법으로 나타났다. 따라서 기립 훈련기에서 동작관찰 체간훈련은 급성기 뇌졸중 환자에게 능동적이고 동적인 체간훈련을 제공할 수 있는 새로운 중재 방법으로 사용될 수 있을 것이다.
        4,500원
        51.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 인지 중재 비율을 조절한 점진적 관찰감소 동작관찰훈련과 기존의 동작관찰훈련에 대한 상지기능 변화를 비교하여 효율적인 중재 방법을 알아보고자 실시하였다. 연구방법 : 14명의 만성 뇌졸중 환자를 대상으로 7명의 실험군은 점진적 관찰감소 동작관찰훈련을, 7명의 대조군은 기존의 동작관찰훈련을 주 3회, 30분씩, 4주간 실시하였고 각 군은 기존에 실시하던 전통적 작업치료 및 물리치료 역시 시행하였다. 상지 운동기능의 사전, 사후 평가는 울프운동기능검사(Wolf Motor Function Test; WMFT), 상지기능장애 설문지(Disabilities of the Arm, Shoulder and Hand; DASH), 상자와 나무토막 검사(Box and Block Test; BBT)를 사용하였고, 각 군의 중재 전과 후의 차이는 윌콕슨 부호 순위검정(Wilcoxon signed-ranks test), 두 군 간의 중재 후 효과 비교는 맨 휘트니검정(Mann-Whitney U test)을 사용하여 분석하였다. 결과 : 점진적 관찰감소 동작관찰훈련군과 기존의 동작관찰훈련군은 모두 WMFT, DASH, BBT에서 통계적으로 유의한 변화가 있었다(p<.05). 점진적 관찰감소 동작관찰훈련군과 기존의 동작관찰훈련군의 상지기능 변화량 비교에서는 WMFT의 소요시간과 DASH의 점수에서 점진적 관찰감소 동작관찰훈련군이 더 많은 변화 가 있었으며 통계적으로 유의한 차이가 있었다(p<.05). 결론 : 본 연구 결과 중재기간에 따라 인지 중재 비율을 고려한 점진적 관찰감소 동작관찰훈련이 기존의 동작관찰훈련보다 상지기능 향상에 효과적이었다는 것을 알 수 있었다. 따라서 만성 뇌졸중 환자의 상지기능 향상을 위한 동작관찰훈련의 중재 시 인지비율을 고려한 중재 전략이 필요하다.
        4,300원
        53.
        2018.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The proportion of collision in the total marine accidents is high. The main causes of collisions are navigation rule violation, safety speed violation, neglected watch-keeping and improper collision avoidance action. There are two main ways of avoiding collision situations during maritime navigation: the method of altering course and reducing ship’s speed. The purpose of this study is to analyze the result of the collision avoidance action of the reserve officer in case of encountering a multiple number of ships using the ship handling simulator. Full-mission ship handling simulator was used to experiment the situation scenarios that encountered multiple ships. After the experiment, the questionnaire about the experiment was investigated. A total of 50 subjects were participated in the experiment. Experimental results showed that the number of the experimenters who used the engine was 11 and the number of the experimenters who did not use the engine was 39. In the case of using the engine, there were 0 collision accident, 1 grounding accident, and 10 no accidents. However, when the engine was not used, there were 28 collision accidents, 2 grounding accidents, and 9 no accidents. The causes of these results can be found in the survey results. 74 % of the non used engine participants said they were hesitate to use the engine. As can be seen from these results, the reserve officer are hesitant to use the engine and need a way to get correct of it. Maritime course subject can emphasize the importance of using ship’s engines and case study also can be it. So, It is considered that various case study scenario will need to developed by various tools in the future.
        4,000원
        54.
        2018.03 구독 인증기관 무료, 개인회원 유료
        K+ channels are key components of the primary and secondary basolateral Cl- pump systems, which are important for secretion from the salivary glands. Paroxetine is a selective serotonin reuptake inhibitor (SSRI) for psychiatric disorders that can induce QT prolongation, which may lead to torsades de pointes. We studied the effects of paroxetine on a human K+ channel, human ether-a-go-go-related gene (hERG), expressed in Xenopus oocytes and on action potential in guinea pig ventricular myocytes. The hERG encodes the pore-forming subunits of the rapidly-activating delayed rectifier K+ channel (IKr) in the heart. Mutations in hERG reduce IKr and cause type 2 long QT syndrome (LQT2), a disorder that predisposes individuals to lifethreatening arrhythmias. Paroxetine induced concentrationdependent decreases in the current amplitude at the end of the voltage steps and hERG tail currents. The inhibition was concentration-dependent and time-dependent, but voltageindependent during each voltage pulse. In guinea pig ventricular myocytes held at 36℃, treatment with 0.4 μM paroxetine for 5 min decreased the action potential duration at 90% of repolarization (APD90) by 4.3%. Our results suggest that paroxetine is a blocker of the hERG channels, providing a molecular mechanism for the arrhythmogenic side effects of clinical administration of paroxetine.
        4,000원
        55.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 전문가와 교사의 협력적 실행연구를 통해 유아교육현장에서 만나게 되는 유아의 정서조절과 관련된 행동문제에 대한 유아교사의 인식 및 지도가 어떻게 변화되었는지를 알아보는 것이다. 이를 위해 본 연구는 D광역시에 위치한 유치원의 만 3세반 교실에서 약 3개월 동안 진행되었으며 유아교육과 현직교수 2인과 유치원 교사 3인이 참여하였다. 협력적 실행연구의 순환과정을 통해 나타난 유아교사의 변화를 파악하기 위해 교사들이 작성한 유아관찰 기록지, 교사저널, 연구일지와 교실관찰, 전화통화 및 이메일 교신, 면담내용의 자료를 근거이론의 절차방법을 통해 분석하였다. 연구결과, 유아교사들은 협력적 실행연구에 참여하면서 정서조절 행동문제는 유아가 정서적인 어려움을 호소하는 메시지이고, 유아가 처한 환경적 맥락에서의 어려움을 반영하며, 행동문제를 하는 유아가 곧 문제유아를 의미하는 것은 아님을 인식하게 되었다. 다음으로 협력적 실행연구에 참여한 유아교사들은 정서조절 행동문제에 대한 자신의 지도실제를 반성적인 사고를 통해 살펴보기 시작했으며, 다양한 방법으로 관찰하고 객관적으로 분석하게 되었다. 또한 정서조절 행동문제를 지도하기 위하여 유아에게 관심을 가지고 믿고 이해하고 존중하기 시작했으며, 유아에게 가장 적합한 방법을 찾아 적용하였고, 정서조절 행동문제를 지도하는 과정에서 부모 및 동료교사들과 협력하였다.
        6,100원
        56.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A theoretical model has been studied to describe the sound radiation analysis for a railway under the action of harmony line moving forces. When a railway is analyzed, it had been modeled as curved beams with distributed springs and dash-pots that represent the radial, tangential stiffness and damping of rail, respectively. The reaction due to fluid loading on the vibratory response of the curved beam is taken into account. The curved beam is assumed to occupy the plane y=0 and to be axially infinite. The curved beam material and elastic foundation are assumed to be lossless Bernoulli-Euler beam theory including a tension force(T), damping coefficient(C) and stiffness of foundation(Κ2) will be employed. The expression for sound power is integrated numerically and the results examined as a function of Mach number(M), wave-number ratio(γ) and stiffness factor(Ψ).
        4,000원
        57.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the current study, we investigated the inhibitory activity of water soluble β-glucan from oat (Avena sativa) against various digestive enzymes such as α-glucosidase, sucrase, maltase and glucoamylase. Inhibition of these enzymes involved in the absorption of disaccharide can significantly decrease the post-prandial increase of blood glucose level after a mixed carbohydrate diet. The β-glucan had the highest documented rate of small intestinal sucrase inhibitory activity (2.83 mg/mL, IC50) relevant for potentially managing post-prandial hyperglycemia. Furthermore, we evaluated the effects of β-glucan on the level of post-prandial blood glucose in animal model. The post-prandial blood glucose levels were tested two hours after sucrose/starch administration, with and without β- glucan (100, and 500 mg/kg-body weight). The maximum blood glucose levels (Cmax) of β-glucan administration group were decreased by about 23% (from 219.06±27.82 to 190.44±13.18, p<0.05) and 10% (from 182.44±13.77 to 165.64±10.59, p<0.01) in starch and sucrose loading test, respectively, when compared to control in pharmacodynamics study. The β -Glucan administration significantly lowered the mean, maximum, and minimum level of post-prandial blood glucose at 30 min after meal. In view of the foregoing, it is felt that our findings suggest that β-glucan from oat serves to reduce post-prandial blood glucose rise secondary to slower absorption of glucose in the small intestine, via carbohydrate hydrolyzing enzymes inhibition.
        4,000원
        58.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 재배가 용이하고 민간요법에서 다양하게 이용되고 있는 곰보배추의 에탄올 추출물이 화장품 소재로서 가능성이 있는지를 알아보기 위해 항산화, 미백효능에 대하여 관찰하였다. B16F10 세포에서 곰보배추 에탄올 추출물 25, 50, 100 ㎍/mL 농도에서 독성이 나타나지 않았다. DPPH radical 소거능을 관찰한 결과 모든 농도에서 소거능을 보여주었고, 50 ㎍/mL의 농도에서 65.2%, 100 ㎍/mL에서 77.6%의 강한 항산화 효능을 나타냈다. Raw 264.7 세포 내에서 ROS 생성 저해능을 관찰한 결과 농도 의존적으로 유의하게 나타냈고, 100 ㎍/mL 농도에서는 39.1% 억제하는 것으로 나타났다. NO생성 억제를 관찰하기 위해 Raw 264.7 세포에 곰보배추 에탄올 추출물을 25, 50, 100 ㎍/mL 농도 별로 첨가하여 관찰한 결과 농도 의존적으로 NO생성을 억제하였다. 시험관 내에서 L-DOPA와 L-tyrosine을 이용하여 곰보배추 에탄올 추출물이 tyrosinase activity를 농도 의존적으로 억제하는 것을 나타냈다. 세포 내에서 MSH를 가한 B16F10 세포에 곰보배추 에탄올 추출물을 25, 50, 100 ㎍/mL의 melanin 함량을 관찰한 결과 농도 의존적으로 억제하는 것을 보여주며 100 ㎍/mL에서 30.7%로 억제하였다. 따라서 곰보배추 에탄올 추출물이 항산화 기능이 있는 미백 기능성 화장품의 소재로서 개발 가능성이 충분히 있는 것으로 사료된다.
        4,000원
        59.
        2017.10 구독 인증기관·개인회원 무료
        Bactrocera zonata (Peach fruit flies) is a polyphagous fruit pest native to South and South-East area and now foundin more than 20 countries. This species is not only a serious pest of peach but also is capable of infesting various speciesof 14 plant families. In Korea, they are potential pests of a number of economically important crops including peach,apricot, apple, and even Citrus spp. In northern India, B. zonata is currently considered to be more important fruit pestthan the notorious oriental fruit flies (B. dorsalis). Due to the high risk of potential introduction to southern part of Korea,we put together a national action plan against the peach fruit fly in order to quickly and completely suppress invadingpopulation of this pest species.
        60.
        2017.06 구독 인증기관 무료, 개인회원 유료
        Recent studies indicate that mitochondria are an important source of reactive oxygen species (ROS) in the spinal dorsal horn. In our previous study, application of malate, a mitochondrial electron transport complex I substrate, induced a membrane depolarization, which was inhibited by pretreatment with ROS scavengers. In the present study, we used patch clamp recording in the substantia geletinosa (SG) neurons of spinal slices, to investigate the cellular mechanism of mitochondrial ROS on neuronal excitability. DNQX (an AMPA receptor antagonist) and AP5 (an NMDA receptor antagonist) decreased the malate-induced depolarization. In an external calcium free solution and addition of tetrodotoxin (TTX) for blockade of synaptic transmission, the malateinduced depolarization remained unchanged. In the presence of DNQX, AP5 and AP3 (a groupⅠ metabotropic glutamate receptor (mGluR) antagonist), glutamate depolarized the membrane potential, which was suppressed by PBN. However, oligomycin (a mitochondrial ATP synthase inhibitor) or PPADS (a P2 receptor inhibitor) did not affect the substrates-induced depolarization. These results suggest that mitochondrial substrate-induced ROS in SG neuron directly acts on the postsynaptic neuron, therefore increasing the ion influx via glutamate receptors.
        4,000원
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