검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 274

        21.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 생산자와 시장의 기호성이 우수한 스프레이 장미 품종 ‘Haesal’의 유용한 화색변이 품종을 단기간에 육성하기 위해 삽수와 발근삽목묘에 각각 감마선을 처리한 후 변이 발생 양상과 주요 화색변이의 생육특성을 조사하기 위해 실시하였다. 감마선 처리 시료 형태에 상관없이 선량이 높아질수록 식물체 치사율은 높아졌고 신초의 발생량과 신초 생장량이 감소하였다. 50% 치사선량(LD50, Lethal dose 50)은 삽수는 70Gy부터, 발근삽목묘는 90Gy부터였고 변이 발생률은 삽수와 발근삽목묘에서 각각 2.6%, 3.1% 였으며, 변이형태는 양쪽 모두 완전변이체, 키메라, 그리고 꽃 형태변이였다. 감마선을 처리한 삽수로부터 ‘Haesal’과 거의 유사한 특성을 가진 화색변이 MUL-1과 MUL-2를 각각 70Gy와 50Gy 선량에서 유기하였고 특성을 조사한 결과 꽃 직경과 꽃잎수, 절화수량은 ‘Haesal’에 비해 조금 적었지만 화형과 잎의 특성, 절화장 등은 ‘Haesal’과 차이가 없었다.
        4,000원
        22.
        2019.10 구독 인증기관 무료, 개인회원 유료
        최근 홍콩에서 중국어를 모국어로 사용하지 않는 학생들을 합격시킨 주류 중등학교들이 급증하고 있다.(2016, 입법회). 이 학교는 이러한 학생의 학습 차이를 고려하여 다양한 대처를 필요로 하고 있다. 다양한 방식을 채택하여 학생들이 중국어 학습을 잘 마칠 수 있게 지원하여, 그들의 진학이 구직난을 해소하고 사회 상류로의 진출 기회가 될 수 있도록 해야 한다.(Leung et al 2017; Loh & Tam, 2016). (중국은) 중국어를 사용하지 않는 학생들에게 적합한 중국어 교육법을 제공하 는 것이 필요하다고 판단하고 있으며, 이는 해결해야 할 급선무 문제가 되었다.(shum, 2015). 본 연구는 이러한 홍콩의 상황에 집중하였다. 「阅读促进学习」(Rose&Martin, 2012) 교수법은 비 중국어 사용자 학생들의 비율이 비교적 높은 중등학교 한 곳을 선정하고, 제2외국어 교육 과정을 중국어로 하는 대외한어교육현장에서 제 2외국어 학습 기관(홍콩교육국, 2014) 및 국제 일반 중등학교 교육 증서(IGCSE)의 교육과정 개요를 참조하여, 본 교육과정(커리큘럼)을 수정 하였다. 협업과 회의를 통해 공동으로 수업을 준비하고 교육현장을 관찰하는데, 교사와 학생들이 모인 소그룹 인터뷰, 필기 및 수업 원본 분석 등의 방법을 진행하였다. 이를 통해 본 교수법이 학생들에게 설명문 종류의 글을 읽고 쓰는 능력을 향상시키고 학습 동기를 높일 수 있는지의 여부를 검토하였다. 교사는 학생들이 본문을 자세하게 읽도록 한 후, 그룹 협업을 통해 그 문장에 서 핵심 키워드를 발췌하여 노트에 기록하도록 학생들을 지도하는 방법(Note Making)을 시행하고, 이어서 학생들은 상호 간의 교류와 협력에 의해 문장 속에 등장한 핵심 단어들과 구 형식, 문장 형식을 활용하여, 협업을 통해 새로운 글을 창작하고, 마지막으로 학생들이 각자 개별적으로 작문을 수행하게 하였다. 본 연구를 통해, 상술한 단계가 학생들이 문장 형식에 따른 다양한 언어 능력의 차이를 이해하도록 돕는데 효과적이며, 서로 다른 글쓰기 활동에 활용할 수 있음을 발견했다. 원전 분석 및 소그룹 인터뷰 또한 위 교수법이 학생들의 중국어 학습 동기를 향상시키는 데 효과가 있음과 학생들의 학습에 대한 믿음이 증가한 것을 보여주었다. 본 연구는 阅读促进学习 교수법이 학생들의 읽기와 쓰기 능력을 개선하고, 각 교육 절차의 실천적 성과들이 모두 시사성이 있음을 검증하였다는데 그 의의가 있다.
        6,900원
        23.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        에메리개미는 여왕개미와 수개미가 유전적으로 복제되어 번식한다고 알려져 있으며, 여왕개미의 날개형태가 장시형과 단시형으로 나타난다. 장시형은 정상적인 날개형태이고, 이보다 짧은 날개형태는 단시형이라고 한다. 장시형과 단시형 모두 한 종으로 취급되지만, 두 가지 점에서 종 지위에 대한 조사가 필요하다. 첫째, 자연 상태에서는 두 날개형이 함께 발견되지 않고, 둘째, 날개형이 육안으로 뚜렷하게 구분된다. 또한 복제되어 번식한 여왕개미가 단수체인지 배수체인지 조사가 필요하다. 따라서 우리는 본 연구에서 에메리개미 유전체 크기를 추정하여 두 날개형은 동종이며, 여왕개미는 배수체임을 확인하였다.
        4,000원
        24.
        2018.12 구독 인증기관 무료, 개인회원 유료
        Reactive oxygen species (ROS) and nitrogen species (RNS) are involved in cellular signaling processes as a cause of oxidative stress. According to recent studies, ROS and RNS are important signaling molecules involved in pain transmission through spinal mechanisms. In this study, a patch clamp recording was used in spinal slices of rats to investigate the action mechanisms of O2 ⦁- and NO on the excitability of substantia gelatinosa (SG) neuron. The application of xanthine and xanthine oxidase (X/XO) compound, a ROS donor, induced inward currents and increased the frequency of spontaneous excitatory postsynaptic currents (sEPSC) in slice preparation. The application of S-nitroso-N-acetyl-DLpenicillamine (SNAP), a RNS donor, also induced inward currents and increased the frequency of sEPSC. In a single cell preparation, X/XO and SNAP had no effect on the inward currents, revealing the involvement of presynaptic action. X/XO and SNAP induced a membrane depolarization in current clamp conditions which was significantly decreased by the addition of thapsigargin to an external calcium free solution for blocking synaptic transmission. Furthermore, X/XO and SNAP increased the frequency of action potentials evoked by depolarizing current pulses, suggesting the involvement of postsynaptic action. According to these results, it was estblished that elevated ROS and RNS in the spinal cord can sensitize the dorsal horn neurons via pre- and postsynaptic mechanisms. Therefore, ROS and RNS play similar roles in the regulation of the membrane excitability of SG neurons.
        4,000원
        25.
        2018.11 구독 인증기관·개인회원 무료
        Recent research on stem cell conditioned medium (CM) has been revealed that CM could influence on the embryo development when supplemented to in vitro culture medium. However, the optimal basal medium for CM production has not determined although it is the fundamental factor of CM. The purpose of this study is to examine the effect of human derived adipose stem cell CM (hASC-CM) with different basal medium on mice embryo development after parthenogenetic activation (PA). hASC-CM was collected from 2 kinds of serum free basal medium, DMEM and KSFM, respectively on day 5 from the culture of hASC isolated from human fat tissue. Intra-peritoneal injection of PMSG and hCG was conducted into 7-week-old ICR mice for superovulation. The oocytes were recovered from the oviductal ampulla, 18 h after hCG injection, and denuded using 0.1% hyaluronidase. PA of oocytes was conducted with KSOM media including strontium chloride. The parthenotes were in vitro cultured in 3 groups: 100% KSOM (Control), 75% KSOM + 25% DMEM or KSFM without FBS (DMEM or KSFM group) and 75% KSOM + 25% hASC-CM from DMEM or KSFM (DMEM-CM or KSFM-CM group). Cleavage rate was assessed after 2 days post IVC and blastocyst formation rate was evaluated after 6 days post IVC both using stereomicroscope. Total cell number of blastocysts was counted by Hoechst staining. 1way ANOVA from Graphpad prism 5 was used for statistical analysis and the values are presented as means ± standard error of mean. As a result, blastocyst formation rate of DMEM-CM group (16.09±3.32%, P<0.05) was significantly lower than control and DMEM group (34.43±2.89% and 34.49±5.34%, P<0.05) but cleavage rate and total cell number of blastocysts showed no significant difference among groups. In case of KSFM, there was no significant difference in cleavage rate, blastocyst formation rate and total cell number of blastocysts among the control, KSFM group and KSFM-CM group. The sort of basal medium used for the CM collection affected the development of parthenotes during in vitro culture differently. Therefore, further research should be conducted to find out the alternative basal medium of CM able to improve the embryo development. This research was supported by Nature Cell (#550-20170028), Cooperative Research Program of RDA (CCAR, #PJ013954022018), Research Institute for Veterinary Science and the BK21 plus program.
        29.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The formation mechanism and photocatalytic properties of a multiwalled carbon nanotube (MWCNT)/TiO2- based nanotube (TNTs) composite are investigated. The CNT/TNT composite is synthesized via a solution chemical route. It is confirmed that this 1-D nanotube composite has a core-shell nanotubular structure, where the TNT surrounds the CNT core. The photocatalytic activity investigated based on the methylene blue degradation test is superior to that of with pure TNT. The CNTs play two important roles in enhancing the photocatalytic activity. One is to act as a template to form the core-shell structure while titanate nanosheets are converted into nanotubes. The other is to act as an electron reservoir that facilitates charge separation and electron transfer from the TNT, thus decreasing the electronhole recombination efficiency.
        4,000원
        30.
        2016.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        4H- and 6H-SiC grown by physical vapor transport method were investigated by transmission electron microscopy (TEM). From the TEM diffraction patterns observed along the [11-20] zone axis, 4H- and 6H-SiC were identified due to their additional diffraction spots, indicating atomic stacking sequences. However, identification was not possible in the [10-10] zone axis due to the absence of additional diffraction spots. Basal plane dislocations (BPDs) were investigated in the TEM specimen prepared along the [10-10] zone axis using the two-beam technique. BPDs were two Shockley partial dislocations with a stacking fault (SF) between them. Shockley partial BPDs arrayed along the [0001] growth direction were observed in the investigated 4H-SiC. This arrayed configuration of Shockley partial BPDs cannot be recognized from the plan view TEM with the [0001] zone axis. The evaluated distances between the two Shockley partial dislocations for the investigated samples were similar to the equilibrium distance, with values of several hundreds of nanometers or even values as large as over a few micrometers.
        4,000원
        31.
        2016.10 구독 인증기관·개인회원 무료
        Vollenhovia emeryi (Formicidae: Myrmicinae) is divided into two morphs based on the wing length of the queen caste: the long-winged with a normal wing and the short-winged with the aberrant short wing. The phylogenetic analysis shows that the short-winged is derived from the long-winged. In Korea, only the long-winged morph is infected with Wolbachia while the short-winged is devoid of the bacterium suggesting that the short-winged evolved the resistance to the bacterial infection. Intriguingly, some Japanese short-winged colonies proved to still be infected with the bacterium. We hypothesized that the infected Japanese short-winged is the intermediate form in the process to complete cure. However, the data of the MLST and the measurement of Wolbachia density did not support our hypothesis. Our further experiment using microsatellite markers shows that the infected Japanese short-winged shows the similar genetic background to the long-winged. In this presentation we will discuss the potential resistance evolution in the Korean short-winged and future research direction at the genome level.
        32.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Even though klotho deficiency in mice exhibits multiple aging-like phenotypes, studies using large animal models such as pigs, which have many similarities to humans, have been limited due to the absence of cell lines or animal models. The objective of this study was to generate homozygous klotho knockout porcine cell lines and cloned embryos. A CRISPR sgRNA specific for the klotho gene was designed and sgRNA (targeting exon 3 of klotho) and Cas9 RNPs were transfected into porcine fibroblasts. The transfected fibroblasts were then used for single cell colony formation and 9 single cell–derived colonies were established. In a T7 endonuclease I mutation assay, 5 colonies (#3, #4, #5, #7 and #9) were confirmed as mutated. These 5 colonies were subsequently analyzed by deep sequencing for determination of homozygous mutated colonies and 4 (#3, #4, #5 and #9) from 5 colonies contained homozygous modifications. Somatic cell nuclear transfer was performed to generate homozygous klotho knockout cloned embryos by using one homozygous mutation colony (#9); the cleavage and blastocyst formation rates were 72.0% and 8.3%, respectively. Two cloned embryos derived from a homozygous klotho knockout cell line (#9) were subjected to deep sequencing and they showed the same mutation pattern as the donor cell line. In conclusion, we produced homozygous klotho knockout porcine embryos cloned from genome-edited porcine fibroblasts.
        4,000원
        33.
        2016.09 구독 인증기관 무료, 개인회원 유료
        Reactive oxygen species (ROS) and nitrogen species (RNS) are both important signaling molecules involved in pain transmission in the dorsal horn of the spinal cord. Xanthine oxidase (XO) is a well-known enzyme for the generation of superoxide anions (O2 ⦁-), while S-nitroso-N-acetyl-DLpenicillamine (SNAP) is a representative nitric oxide (NO) donor. In this study, we used patch clamp recording in spinal slices of rats to investigate the effects of O2 ⦁- and NO on the excitability of substantia gelatinosa (SG) neurons. We also used confocal scanning laser microscopy to measure XO- and SNAP-induced ROS and RNS production in live slices. We observed that the ROS level increased during the perfusion of xanthine and xanthine oxidase (X/XO) compound and SNAP after the loading of 2′,7′-dichlorofluorescin diacetate (H2DCF-DA), which is an indicator of intracellular ROS and RNS. Application of ROS donors such as X/XO, β -nicotinamide adenine dinucleotide phosphate (NADPH), and 3-morpholinosydnomimine (SIN-1) induced a membrane depolarization and inward currents. SNAP, an RNS donor, also induced membrane depolarization and inward currents. X/XO-induced inward currents were significantly decreased by pretreatment with phenyl N-tert-butylnitrone (PBN; nonspecific ROS and RNS scavenger) and manganese(III) tetrakis(4-benzoic acid) porphyrin (MnTBAP; superoxide dismutase mimetics). Nitro-L-arginine methyl ester (NAME; NO scavenger) also slightly decreased X/XO-induced inward currents, suggesting that X/XO-induced responses can be involved in the generation of peroxynitrite (ONOO-). Our data suggest that elevated ROS, especially O2 ⦁-, NO and ONOO-, in the spinal cord can increase the excitability of the SG neurons related to pain transmission.
        4,000원
        34.
        2016.07 구독 인증기관·개인회원 무료
        In 2015, the size of China’s cross-border shopping market was 97.3 billion dollars. The market increased by 63% during the last 5 years (Mun, 2016), and is expected to rise to 220 billion dollars by the year 2020. According to the e-commerce export trends of the Korea customs administration, in August 2015, the largest exporter was China (42%) and the largest export was clothing (52%) (Song, 2016). Accordingly, Korean corporations and brands are focusing on Haitao (海淘族, who enjoy cross-border online shopping) and proceeding to build customized websites and mobile platforms. Even though China's cross-border shopping is consistently growing, insufficient information is available to Chinese consumers. Hence, this research study is based on the theory of planned behavior (TPB) and analyzes the factors that influence the behavior of Chinese consumers in cross-border shopping the theory of planned behavior (TPB). The objective of this research is to identify how shopping values, subjective norms, attitudes, and perceived behavior controls influence the behavioral intention of Chinese consumers toward cross-border shopping. The respondents of this study were 20 to 30-year-old Chinese who live in first and second-tier cities in China, and have experienced cross-border shopping. Samples were collected through an online survey website, Sojump (问卷星), and 205 valid questionnaire responses were received. Reliability analysis, factor analysis and SEM (Structural Equation Modeling) were used to validate the measurement model and test the hypotheses with SPSS 21.0 and AMOS 18.0. The findings reveal that the utilitarian values and perceived behavioral controls of Chinese consumers have a positive effect on their attitudes toward cross-border shopping. Furthermore, their behavioral intentions were affected by their attitudes, and their perceived behavioral controls in cross-border shopping excluded subjective norms. The results of the study have implications for Korean fashion retailers who plan to exploit Chinese markets and for the formation of a theoretical basis for cross-border shopping.
        35.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effects of various mulching materials on growth and yield of okra (Abelmoschus esculentus L. Moench). Three kinds of polyethylene (PE) mulching materials were used which are: black (Black), green (Green), and white and black on both sides (White), black non-woven fabric (Fabric), and barley straw (Straw) and the control plot (Control) were also used in this study. The change of soil temperature was observed in various mulching materials with Green showing the highest average temperature of 24.4o, followed by Black > Fabric > Control > White > Straw. The variation of plant length,, aboveground weight, and root weight were constant in the order of Green > Black > White > Fabric > Control > Straw. Total yield (number of fruits) were 281,000 in Green which was the highest yield, and the least was from Straw which was 62.3% of Green. Total weight of fruits in Green was 395 kg which was the heaviest, and in Straw was least with 226 kg Hence, the weight of fruits
        4,000원
        36.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Antibiotic Detection Kit (Combination I), a lateral flow immunoassay (LFIA) developed for detecting antibiotic residues in milk, was utilized for the analysis of antibiotic residues in the muscle tissue of olive flounder. After 5-h treatment of samples by placing them in water dosed with sulfadimethoxine (SDM; 200 g/ton water), the residue depletion of SDM was investigated in 25 cultured olive flounders (Paralichthys olivaceus). Muscles from fish were sampled before treatment and on the 1st, 2nd, 3rd, 4th and 5th days after treatment. The concentration of SDM in the muscle was then determined by LFIA. The absorbance ratio of the sample to the control blank (Bs/Bo) was employed as an index to determine the residue in olive flounder muscle. To investigate the recovery rate, standard solutions were added to muscle samples to obtain final concentrations of 25 and 50 ng/mL in the muscle. The recovery rates of all spiked samples were >96.6% of the spiked value. SDM was detectable in the muscle of fish treated with the drug until the 1st day of the withdrawal period. The present study shows that the LFIA can be easily adopted to detect SDM residues in the tissue of farmed fish.
        4,000원
        37.
        2015.12 구독 인증기관 무료, 개인회원 유료
        Nitric Oxide (NO) is an important signaling molecule in the nociceptive process. Our previous study suggested that high concentrations of sodium nitroprusside (SNP), a NO donor, induce a membrane hyperpolarization and outward current through large conductances calcium-activated potassium (BKca) channels in substantia gelatinosa (SG) neurons. In this study, patch clamp recording in spinal slices was used to investigate the sources of Ca²+ that induces Ca²+-activated potassium currents. Application of SNP induced a membrane hyperpolarization, which was significantly inhibited by hemoglobin and 2-(4-carboxyphenyl) -4,4,5,5- tetramethylimidazoline-1-oxyl-3-oxide potassium salt (c-PTIO), NO scavengers. SNP-induced hyperpolarization was decreased in the presence of charybdotoxin, a selective BKCa channel blocker. In addition, SNP-induced response was significantly blocked by pretreatment of thapsigargin which can remove Ca²+ in endoplasmic reticulum, and decreased by pretreatment of dentrolene, a ryanodine receptors (RyR) blocker. These data suggested that NO induces a membrane hyperpolarization through BKca channels, which are activated by intracellular Ca²+ increase via activation of RyR of Ca²+ stores.
        4,000원
        1 2 3 4 5