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        검색결과 16

        1.
        2023.10 구독 인증기관·개인회원 무료
        기존에는 생산되는 키틴과 키토산의 대부분이 게, 새우등 갑각류 껍질에서 유래하였다. 하지만 어업에 의존하 는 기존 갑각류 비해 친환경적이며 품질 유지에 이점을 가지는 곤충으로부터 유래한 키틴이 최근 주목 받기 시작 하며 연구가 활발해지고 있다. 이에 키토산이 남조류의 응집을 통해 녹조 제거 효과를 가지며 기존에 녹조를 억제하기 위해 널리 사용되던 살조제들이 독성을 띠어 환경에 악영향을 미치는 문제를 해결할 수 있다는 연구를 참고하여 매미 탈피각으로부터 추출한 키토산을 녹조 방제에 활용해 보고자 하였다. 매미 탈피각으로부터 키토 산을 추출하고 대표적인 녹조 원인종인 Microcystis aeruginosa 배양 후 추출한 키토산을 처리하여 녹조의 응집 효과를 관찰하였다. 본 연구에서 새로운 키토산 추출 원으로서 매미 탈피각의 가능성을 제시하였으며 이를 녹조 방제에 활용함으로써 버려지는 자원인 매미 탈피각의 활용 방안을 제시하였다.
        2.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Porous carbons are considered promising for CO2 capture due to their high-pressure capture performance, high chemical/ thermal stability, and low humidity sensitivity. But, their low-pressure capture performance, selectivity toward CO2 over N2, and adsorption kinetics need further improvement for practical applications. Herein, we report a novel dual-templating strategy based on molten salts (LiBr/KBr) and hydrogen-bonded triazine molecules (melamine–cyanuric acid complex, MCA) to prepare high-performance porous carbon adsorbents for low-pressure CO2. The comprehensive investigations of pore structure, microstructure, and chemical structure, as well as their correlation with CO2 capture performance, reveal that the dual template plays the role of porogen for multi-hierarchical porous structure based on supermicro-/micro-/meso-/ macro-pores and reactant for high N/O insertion into the carbon framework. Furthermore, they exert a synergistic but independent effect on the carbonization procedure of glucose, avoiding the counter-balance between porous structure and hetero-atom insertion. This enables the preferred formation of pyrrolic N/carboxylic acid functional groups and supermicropores of ~ 0.8 nm, while retaining the micro-/meso-/macro-pores (> 1 nm) more than 60% of the total pore volume. As a result, the dual-templated porous carbon adsorbent (MG-Br-600) simultaneously achieves a high CO2 capture capacity of 3.95 mmol g− 1 at 850 Torr and 0 °C, a CO2/ N2 (15:85) selectivity factor of 31 at 0 °C, and a high intra-particle diffusivity of 0.23 mmol g− 1 min− 0.5 without performance degradation over repeated use. With the molecular scale structure tunability and the large-scale production capability, the dual-templating strategy will offer versatile tools for designing high-performance carbon-based adsorbents for CO2 capture.
        4,300원
        4.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of the study was to investigate the effects of incentive spirometry and Ujjayi breathing technique on the pulmonary function of smokers. Subjects were individuals who had a smoking habit of at least a year. Subjects were randomly divided into 3 groups: the incentive spirometry group (n=8), Ujjayi breathing technique (n=9), and a group applying both incentive spirometry as well as Ujjayi breathing technique (n=8). Each intervention was performed twice a day, 5 times a week, for a total of 8 weeks whereupon the change in pulmonary function was evaluated. A spirometer was used to measure FVC, FEV1, and FEV1/FVC. The survey used for this study included the Fagerström Test of Nicotine Dependence (FTND) and the Shortness of Breath Questionnaire (SOBQ). Study results for the comparison within groups showed that in the group that performed both the incentive spirometry and Ujjayi breathing technique, FEV1 improved with statistical significance (p<.05). Furthermore, within this comparison the FEV1/FVC improved with statistical significance. Comparison amongst the groups showed no statistically significant differences in all areas. Following, to effectively increase pulmonary function in young adult smokers, both incentive spirometry and Ujjayi breathing technique should be employed together.
        4,000원
        5.
        2017.10 구독 인증기관·개인회원 무료
        The purpose of this study is to improve practical skill evaluation method of mushroom - trained certified technician's practical skill evaluation which is one of national qualification tests based on national incompetency standards. One of the current National Competency Standards (NCS), mushroom - trained certified technician uses NCS based practical assessment method. In order to improve the current practical evaluation method, we try to improve practical evaluation method based on field customized problem solving ability and improve the practical evaluation method, various evaluation methods should be constructed. On the purpose of identify the diversity and problems of the evaluation method, the experts of the group consultation, the mushroom-related research institute and the related industry collaborated to identify the problems of the actual mushroom - trained certified technician practicum test, This study on the evaluation improvement method was carried out. In this study, the contents of practical test of the current mushroom traits were analyzed and the trends of the latest mushroom industry were widely reflected.
        6.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A powder injection molding process is developed and optimized for piezoelectric PAN-PZT ceramics. Torque rheometer experiments are conducted to determine the optimal solids loading, and the rheological property of the feedstock is evaluated using a capillary rheometer. Appropriate debinding conditions are chosen using a thermal gravity analyzer, and the debound specimens are sintered using sintering conditions determined in a preliminary investigation. Piezoelectric performance measures, including the piezoelectric charge constant and dielectric constant, are measured to verify the developed process. The average values of the measured piezoelectric charge constant and dielectric constant are 455 pC/N and 1904, respectively. Powder injection molded piezoelectric ceramics produced by the optimized process show adequate piezoelectric performance compared to press-sintered piezoelectric ceramics.
        4,000원
        8.
        2018.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구는 완주에서 재배된 세계 주요 11개 적포도 품종으로 제조된 적포도주의 향기 성분을 headspace-solid phase microextraction 분석법으로 확인하였다. 향기성분은 총 75종이 확인되었다. 아로마화합물은 그들의 OAV 값에 의해 5 그룹으로 나뉘었다. 알콜, 알데하이드, 에스테르, C6 화합물이 11개 적포도주의 주요한 향기성분이었다. Isoamy alcohol 알콜과 phenylethyl 알콜은 11개 포도주에서 공통적으로 꽃향기, 달콤한 향을 나타내는데 중요한 물질이었다. Octanoic acid, ethyl ester, hexanoic acid ethylester은 모든 레드와인에서 과실향과 꽃향, 달콤한 향을 내는 중요한 성분이었다. 1-Hexanol은 모든 포도주에서 분석되었으나 풀향을 나타내는 향으로 나타났다. Chanceller, Malbec, marchel, Nsrsha, Pinot Meunier, Sangiovetto 포도주의 주요 향기성분은 과실 향인 것으로 나타났으며 Cabernet Franc, Cabernet Sauvignon, Sauvignon Vert 포도주의 주요 향기성분은 풀향인 것으로 조사되었다. 또한, MBA와 Narsha 포도주의 경우 꽃향이 주요 향인 것으로 조사되었다. 본 연구 결과를 바탕으로 적포도주용 품종을 육성할 때 선발기준으로 향기성분 분석을 활용할 수 있을 것으로 판단되었다.
        9.
        2018.04 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The study compared the juice and wine odorants of the Cheongsoo grape cultivar with those of Chardonnay and Reisling wines. The volatile compounds of the three grape varieties were analyzed using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. The most common volatile compounds in the juices from the three cultivars were terpenes, C13-norisoprenoids, etones, alcohols, and aldehydes. Terpenes were established as the most abundant group of volatiles in Cheongsoo grape juice, where as aldehydes predominated in Chardonnay and Riesling juices. Forty-two volatile compounds (acids, alcohols, esters, and others) were detected in the three white wines. The concentration of esters was about four times higher in Cheongsoo wine than in Chardonnay and Riesling wines. Five esters found in the Cheongsoo wine, namely, isoamyl acetate, ethyl butanoate, ethyl hexanoate, ethyl octanoate, and ethyl decanoate, exhibited high odor activity values (OAV) of >1. Furthermore, only Cheongsoo wine had a high OAV for isoamyl acetate odorant, which is associated with banana and sweet aromas. Therefore, the abundant and varied esters are believed to be key volatile fruity/sweet odorants in Cheongsoo wine.
        10.
        2017.08 서비스 종료(열람 제한)
        Spatiotemporal expressions of microRNAs (miRNAs) are altered by the physiological states of cells which could be influenced by microenvironment. Function of miRNAs has been focused as a new regulator of gene expressions and cell differentiation in human health and diseases. We found and identified the several miRNAs, which were related to developmental competence of preimplantation and implantation process of mouse blastocysts and outgrowth embryos by microarray-based bioinformatical studies. In this study, we evaluated three miRNAs expressions related to third cleavage event in conditioned media (CM) and blastocysts. Mouse 2-cell stage embryos were collected and monitored for 9 hours. The embryos were divided two groups as early third cleavage before 9 hours of collection and late third cleavage after 9 hours of collection. They were cultured to blastocyst stage up to day-5 after hCG injection. The total number of cells and the number of cells with fragmented DNA were assessed in blastocysts by terminal dUTP nick-end labelling (TUNEL) staining and DAPI staining. Mean cell number of early third cleavage group was significantly higher than that of late third cleavage group (105.3±8.0 vs 81.8±7.0, p<0.05), but apoptotic index was not different. The miRNAs of CM and blastocysts from early and late group were prepared, and quantified by qRT-PCR with TaqMan probes. The expression levels of three miRNAs (mmu-let-7b, mmu-miR-183, and mmu-miR-429) in CM and blastocysts were slightly upregulated in late third cleavage group. Our study suggested that the expression level of miRNAs could be altered with embryo quality, and miRNAs in CM may be used to predict miRNAs expression of embryos and developmental competence.
        11.
        2017.05 서비스 종료(열람 제한)
        Background : This study was conducted to determine the optimal ginseng greenhouse shading material for minimizing heat injury and maximizing the yield of ginseng plants in an effort to develop a stable ginseng cultivation technology and contribute to popularizing ginseng greenhouse farming. Methods and Results : Three different types of greenhouse shading material were used: polyethylene (PE) film + black screen (95%), light scattering film + black screen (75%), and blue-white vinyl. Important experimental details were implemented in accordance with the Analysis Standard of Agricultural Test and Research set out by the Rural Development Administration. The average greenhouse temperature for the period of May through October was 20.0℃ under the PE film + black screen, 20.2℃under the light scattering film + black screen, and 19.7℃ under the blue/white vinyl. High average photosynthesis rates of ginseng plants were demonstrated by light scattering film+black screen (2.35 μmole CO2/㎡/s) and blue-white vinyl (2.38 μmole CO2/㎡/s), with the PE film + black screen showing a considerably lower photosynthesis rate (1.55 μmole CO2/㎡/s). Heat injury occurred in 0.3%, 10%, and 0.1% of the plants grown under the PE film + black screen, light scattering film + black screen, and blue-white vinyl, respectively. As for the roots, the blue-white vinyl outperformed the other shading materials in root length (25.7 ㎝), taproot length (5.9 ㎝), and the number of fine roots (23.2). The blue-hite vinyl also yielded the greatest root fresh weight (30.2 g), followed by the light scattering film + black screen (29.1 g), with the PE + black screen yielding by far inferior average weight (22.0 g). The highest crude saponin content was yielded by the light scattering film+black screen (16.61 ㎎/g), followed by blue-white vinyl (11.36 ㎎/g) and PE + black screen (11.0 ㎎/g). Conclusion : Comparing the effects of three different shading materials on greenhouse-cultivated 3-year-old ginseng plants, the blue/white vinyl outperformed two other shading materials in most of the growth characteristics, whereas the and the light scattering film + black screen yielded the highest ginsenoside content.
        12.
        2016.10 서비스 종료(열람 제한)
        Background : For increasing saponin content of ginseng cultivated in shaded plastic house, this research was performed to investigate growth characteristics and saponin content of ginseng according to foliar spray of chitosan and water-soluble silicates processing. Methods and Results : The ginseng cultivars to be used this research were Cheonpung, Yeonpung and 1-year-old seedlings of Cheonpung, Yeonpung was transplanted on March 24, 2015. Planting density was 72 plant/3.3㎡and Shading material of plastic house used blue-white shading vinyl. The processing method of organic matter is as follows, we were applied chitosan (40 kg / 10a), silicate (3kg / 10a) to soil scheduled for ginseng cultivation with basal application. Then, we were diluted with chitosan and silicates to 1000-fold and investigated growth characteristics, saponin content of ginseng after foliar spray twice a month from May to September. Conclusion : Photosynthetic rate of ginseng according to treatment of organic matter was higher in the chitosan experimental group compared to the control group and photosynthetic rate of ginseng cultivars was the highest in Cheonpung’s silicate group(3.70 μmole CO2/㎡/s). The growth characteristics in above-ground part of 2-year-old ginseng was a good in the organic matter treatments compared to the control group. Above-ground part’s growth characteristics of ginseng according to treatment of organic matter showed a good trend in plant height, stem length, stem diameter of chitosan experimental group. The growth characteristics in under-ground part of 2-year-old ginseng was a good in the organic experimental groups. In Yeonpung of the chitosan experimental group, fresh root weight per plant was 9.2 g/plant that increased by 46 % compared to the control group. In Cheonpung of the silicate experimental group, fresh root weight per plant was 8.3 g/plant that increased by 56 % compared to the control group. In the chitosan experimental group, crude saponin content of under-ground part was Cheonpung(10.38 ㎎/g), Yeonpung(12.29 ㎎/g), control(11.53 ㎎/g), respectively. In the silicate experimental group, crude saponin content of under-ground part was Cheonpung(11.73 ㎎/g), Yeonpung(14.21 ㎎/g), respectively. Crude saponin content of ginseng according to treatment of organic matter was. generally higher in Yeonpung than Cheonpung.
        13.
        2016.10 서비스 종료(열람 제한)
        Background : Despite the presence of various bioactive compounds in ginseng, there is lack of study about the phenolic metabolites in ginseng especially depending on the cultivation soil and the fertilizer types. Therefore, this study aims to develop an (-)ESI-LC-MS/MS analytical method for the measurement of selected phenolic compounds in the ginseng root. Methods and Results : Total phenol content in ginseng root was measured with the Folin-Ciocalteau method using UV/Vis spectrophotometer. Then, the 56 selected phenolic metabolites in ginseng root were measured with the (-)ESI-LC-MS/MS. The brief LC-MS/MS analytical conditions were as follows; Thermo Scientific Syncronis C18 HPLC Column (250 × 4.6 mm, 5 μm) was used. Optimized instrument settings were as follows: Curtain gas 20 psi, collision gas 2 psi, ion spray voltage –4500 V, nebulizer gas 40 psi, heating gas 70 psi, and its temperature 350℃. Total phenol content was higher in the ginseng cultivated in the paddy-converted field than that in upland. In particular, the total phenol content was about 6% decreased in the ginseng root cultivated with the food waste fertilizer compared to the control (p < 0.05). Six phenolic constituents including caffeic, chlorogenic, p-coumaric, ferulic, gentisic, and salicylic acids were found in the ginseng root by using the LC-MS/MS in MRM (multiple reaction monitoring) Mode. These six phenolic compounds occupied approximately 20% of the total phenol content measured in the corresponding ginseng root. The chlorogenic acid was the most abundant phenolic metabolite found in the ginseng root, accounting for ≥ 95% of the sum of six phenolic compounds, in this study. Conclusion : This preliminary study can be useful for the study on content and composition of phenolic metabolites in ginseng root with the aspect of metabolomics. We plan to further optimize the LC-MS/MS analytical method and then provide the extended understanding on the phenolic metabolism in the ginseng root with respect to the ginseng cultivation conditions.
        14.
        2015.09 서비스 종료(열람 제한)
        The blastocyst should initiate the dynamic changes in morphology and gene expression during hatching and implantation. Blastocyst morphogenesis includes two major events as the formation of blastocoel cavity for lineage differentiation into trophectoderm and inner cell mass, and the blastocyst hatching for implantation. However, there is little known about the relation of dynamic morphogenesis in blastocyst with hatching and implantation potential. In this study, we investigated effects of the dynamic morphogenesis in blastocyst on hatching and implantation potential by outgrowth assay. The cumulative time between each stages was calculated and analyzed. The feature of contraction was evaluated as follows: the number of contractions and the period of circumference was measured. The percentage of reduction during contraction was classified as weak when it was less than 20% and as strong when 20% or more. Compared to embryos of hatching group, embryos of non-hatching group were significantly delayed time at the compacted morula stage by 375.3 min (p<0.05) and at the early blastocyst stage by 650.1 min (p<0.01), respectively. Compared to blastocysts of outgrowth group, blastocysts of non-outgrowth group were significantly delayed at the compacted morula by 404.0 min (p<0.01) and at the early blastocyst stage by 535.4 min (p<0.01), respectively. There is no significant difference in the feature of contraction between hatching and non-hatching groups. However, blastocyst of outgrowth group showed more number of weak contraction and less number of strong contractions, compared with blastocysts of non-outgrowth group (p<0.01). Period of circumference was not significantly different in hatching and outgrowth process. These results suggested that time of blastocoel formation and number of weak contraction in blastocysts were closely related to hatching and outgrowth potential. Dynamic changes of blastocyst formation and contraction could be useful markers to select embryos for predicting the success implantation and pregnancy in human ART program.
        15.
        2014.09 서비스 종료(열람 제한)
        The transcription factor, early growth response protein 1 (EGR1), act as immediate early response genes to control various cellular and reproductive events. Egr1-deficient female mice show infertility by anovulation resulting from luteinizing hormone-β (LH-β) subunit deficiency. While ovulation, fertilization and embryo development normally occur in Egr1-deficient mice treated with a superovulation regime to rescue LH deficiency, embryo implantation was completely failed. The morphology and ultrastructure of uterine tissues were observed by light and transmission electron microscopy during the peri-implantation period in Egr1-deficient mice. To examine alterations in cellular organelles, the uterine horns were fixed with 2.5% glutaraldehyde and postfixed with 1% osmium tetroxide in PBS. After dehydration and infiltration, the samples were embedded in Epon 812. Semi-thin sections 0.5 μm thick were cut with an ultramicrotome and stained with toluidine blue for light microscopy. Thin sections were cut with a diamond knife of the ultramicrotome and placed on copper grids. The sections were double stained and examined under a transmission electron microscope. The height of luminal epithelial cells was decreased and the polarity was poorly differentiated in the Egr1-deficient comparing to the wild mice. The abundant mucinous materials were observed in the surface of luminal epithelial cells of the Egr1-deficient. It was confirmed the microarray and real time qPCR data. The luminal epithelial cells of wild mice had many dense lipophilic granules and healthy mitochondria, but not in the Egr1-deficient. It may related to production and secretion of steroid hormones and prostaglandins in the luminal epithelial cells for successful implantation. These results show that Egr1 is a critical transcription factor to fine-tune subcellular morphological and functional changes for the receptive phase of peri-implantation period of uterine tissue in mice.
        16.
        2012.07 서비스 종료(열람 제한)
        In order to adapt to various environmental stresses, plants have employed diverse regulatory mechanisms of gene expression. Epigenetic changes, such as DNA methylation and histone modifications play an important role in gene expression regulation under stress condition. It has been known that some of epigenetic modifications are stably inherited after mitotic and meiotic cell divisions, which is known as stress memory. To understand molecular mechanisms underlying stress memory mediated by epigenetic modifications, we developed Arabidopsis suspension-cultured cell lines adapted to high salt by stepwise increases in the NaCl concentration up to 120 mM. Adapted cell line to 120 mM NaCl, named A120, exhibited enhanced salt tolerance compared to unadapted control cells (A0). Moreover, the salt tolerance of A120 cell line was stably maintained even in the absence of added NaCl, indicating that the salt tolerance of A120 cell line was memorized even after the stress is relieved. By using salt adapted and stress memorized cell lines, we intend to analyze the changes of DNA methylation, histone modification, transcriptome, and proteome to understand molecular mechanisms underlying stress adaptation as well as stress memory in plants.