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        검색결과 68

        21.
        2013.10 구독 인증기관·개인회원 무료
        Tyrophagus putrescentiae (Tp) as a storage mite inhabitats in stored grains, hay, and straw at agricultural areas. T. putrescentiae stimulates an immune response and triggers inflammatory cytokines release, and thus it is a source of allergen that sensitize and induce allergic reactions. Also, T. putrescentiae has been reported to cause asthma and atopic disease by cross-reactivity with Dermatophagoides pteronyssinus (Dp). The study on T. putrescentiae in human monocytic THP-1 cells is not enough to understand cytokine expression and pathological mechanisms. The aim of this study is to investigate the effect of T. putrescentiae extract (TpE) on production of inflammatory cytokines and expression of mRNA level in THP-1 cells. THP-1 cells are treated with TpE and supernatants were analyzed for the production of cytokines using enzyme-linked immunosorbent assay (ELISA). mRNA level in the culture cells was measured by a reverse transcriptase-polymerase chain reaction (RT-PCR). As a result of this study, TpE significantly induced secretion of interleukin-6, interleukin-8, and monocyte chemotactic protein-1 (MCP-1) in THP-1 cells in time- and dose-dependent manner. These results suggest that TpE may play a role in contributing to inflammatory disease through stimulation of immune cell. Further research of T. putrescentiae is needed to understand the elucidation of the pathogenic mechanism.
        22.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 반추동물의 조사료 자원으로서 거대억새를 개발하기 위한 목적으로 수행되었다. 우리나라에서 새롭게 개발된 품종인 거대억새 1호를 완숙기 이후에 채취하여 in vitro 반추위 발효를 이용해반추위내 pH, 암모니아태 질소, 가스발생량, 휘발성 지방산 생성량 및 건물소화율을 조사하였으며,볏짚과 비교하여 평가하였다. 거대억새는 볏짚에 비하여 유의적으로 높은 반추위내 pH를 나타내었다(p<0.01). 암모니아태 질소의 경우 배양 12시간 이후에는 두 처리구간의 유의적인 차이를 나타내지 않았다 (p>0.05). 배양 6시간 이후 부터는 거대억새의 가스발생량이 볏짚에 비하여 유의적으로 낮게 나타났다 (p<0.05). 휘발성 지방산 생성량에 있어 acetate, propionate, butyrate, valerate 및 총생상량에서 볏짚이 거대억새보다 높게 나타났다. 그러나 iso-butyrate와 iso-valerate에서는 두 조사료원별 차이는 발견되지 않았다. 건물소화율에 있어 배양 12~24시간 사이의 거대억새 소화율이 볏짚에 비하여 유의적으로 나타났다. 결론적으로 거대억새의 이용성은 볏짚의 약 80% 수준인 것으로 나타났다.
        4,000원
        23.
        2009.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        핵연료 운반용 실린더의 재사용을 위한 용기세척공장의 제염공정에 대한 성능을 평가하기 위하여 Na2CO3 + H2O2 혼합용액의 조합을 약간 달리한 2회의 시험을 실행하였다. 각 시험은 모두 일련의 5 단계에 걸쳐 실시되었다. 우라늄 제염의 주 화학종은 Na4UO2(CO3)3 로 식별되었다. 그리고 첫 단계에서의 세척액은 물이었으며, 이 단계에서 50% 이상의 우라늄이 제염되었다. 그 이후로는 단계가 더해 갈수록 우라늄의 제염양은 지수함수적으로 감소하는 경향을 나타내었으며, 화학양론적으로 제거된 우라늄에 비하여 투여된 Na2CO3 의 양은 과다함을 나타내었다. 이러한 결과들에 의하면, 공정최적화를 통하여 Na2CO3 의 투여량 감축, 세척폐액의 감량, 제염단계 축소 등을 꾀할 수 있을 것으로 판단된다.
        4,000원
        24.
        2009.03 구독 인증기관 무료, 개인회원 유료
        In our present study, total methanol extracts prepared from B. platyphylla var. japonica showed a significant increase in cell proliferation upon the induction of oxidative stress by hydrogen peroxide or y-ray irradiation. Total methanol extracts were fractionated into five separate preparations i.e. n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these, the ethylacetate and butanol fractions of B. platyphylla var. japonica showed the highest protective effects against oxidative stress induced by hydrogen peroxide. These fractions also showed strong protective effects against y-ray irradiation. When we evaluated the cytotoxicity of these fractions, the butanol fraction showed no effects in a colony formation assay. In addition, the butanol fraction showed a cell proliferation activation effect evidenced by significant increase in the colony formation of y-ray irradiated cells. Both a radical scavenging activity and clonogenic activity assay suggested that the mechanism behind this protective effect against reactive oxygen species may be due to the radical scavenging and cell proliferation activity of B. platyphylla var. japonica extracts.
        4,000원
        26.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        This study was to taken to demonstrate the effects of exogenous nitric oxide(NO) on hu rnan pu lp cell s ‘ In volvement of cyclic 3’, 5' -monophosphate(cGMP) in p버 paJ protection induced by herne oxygenase-l (J-lO-l) against NO-induced cytotoxicity , By use of Western blotting and cell viabi lity assay, we have examined the cytotoxicity and J-lO-l induction in pulp cells that were treated with NO donor ‘ S-nitroso-N-acetyl-D, L-penici 1 lamine(SNAP) , We have assessed wheathel' HQ--l contributes the cytoprotective effect against the cytotoxicity caused by NO, and inves tigated the l'elationship between HO-l and cGMP in the s ignaling pathway, SNAP decreased cell via bility but in creased HO-l expl'ession in a concentl'ation- and time一dependent manner in hurnan pu lp cells NO-induced cyto toxicity was inhibited in the presence of the hemin(inducer of HO-l) , whel'eas was en hanced in the pl'esence zinc protoporphyrin IX(ZnPP IX, HO-l inhibitor), thus Lhe NO-induced cytoLoxicity was cOl'related with HO- l expression. R‘ etreatment with a rnemhrane-permeable cGMP analog, 8-bromo-cGMP, restored cell death and enhanced the HO-l protein expression induced by SNAP, ln contrast‘ inhibition of guanylate cyclase by lI-l -[1,2,4] ox adiazole[ 4,3 口]quinoxalin-l-one(ODQ) pretreated pulp cells to 1 mM SNAP resulting in marked cytotoxicity , These findings , demonstrating a link between J-lO-l, regulated thl'ough the cGMP system and NO-induced cytotox.icity in huma띠 p버 p ceJls , suggesti ng a protective 1'ole of HO-l in pulp infl ammatory disease
        27.
        2004.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 콘크리트 교량의 지진취약도 곡선을 개발함에 있어 성능 스펙트럼 기법(Capacity Spectrum Method)에 대한 고찰을 통해 가장 적절한 해석방법을 제시하는데 그 목적이 있다. 원래 성능 스펙트럼 기법은 빌딩 구조물을 위한 간략화된 정적 비선형 해석의 일환으로 개발되었는 바, 본 연구에서는 이 기법을 교량의 지진취약도 곡선을 개발하는데 응용하였다. 서로 다른 네가지의 방법으로 성능 스펙트럼 기법을 통해 구해진 취약도 곡선들을 비선형 시간이력해석 방법에 의해 구해진 취약도 곡선과 비교하였다. 취약도 곡선은 두 개의 변수를 가진 lognormal 분포를 따르는 것으로 가정하였으며 PGA(Peak Ground Acceleration)의 함수로 나타내어졌다. FEMA(Federal Emergency Management Agency) SAC(SEAOC-ATC-CUREe) steel 프로젝트에 의해 개발된 로스앤젤레스 지역 60개의 지진이 교량해석을 위해 사용되었다. 성능 스펙트럼 기법과 시간이력해석에 따라 만들어진 교량의 지진취약도 곡선들을 비교 검토한 바, 이 중 하나의 방법이 부합되는 결과를 보여주었다. 요구 스펙트럼 작성시 본 논문에서 제시된 지침을 따르면 비선형 시간이력 해석시와 유사한 결과를 얻을 수 있을 것으로 사료된다. 다만 지진과 교량이 지닌 특수성으로 인해 본 연구의 결과가 항상 적용되는지는 더 심도있는 연구를 통해 검증되어야 할 것이다.
        4,000원
        28.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,900원
        29.
        2018.04 KCI 등재 서비스 종료(열람 제한)
        흡연 유무의 남성을 대상으로 뇌 회백질의 손상 유무를 파악 할 수 있는 확산텐서영상을 검사하여 영상을 획득 한 후 Tract-Based Spatial Statics(TBSS)방법으로 뇌 회백질 부위의 기저핵 신경섬유로의 비등방도 FA(fractional anisotropy)값을 측정 분석한 결과 모든 영역에서 흡연자가 비흡연자보다 비등방성 측정값이 낮게 관찰되었으며 FA값은 통계적으로 유의하였다. 본 연구의 측정한 FA결과 값으로 추측하자면 즉, 흡연이 뇌 회백질 기저핵의 모든 해부학적 미세 구조성 변화에 크게 영향을 미치며 신경 섬유로를 손상시키고 이와 관련된 기능적 이상에 영향을 준다고 할 수 있다.
        30.
        2017.08 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to analyze the muscle activity in the right forearm and shoulderwhile doing the sowing activity by muscle type and work section, and to find the possibility of the utilization of sowing as a muscle exercise and rehabilitative activity based on the results of the analysis. The results showed that the activity of 7 muscles including the upper trapezius near the neck, the upper trapezius near the shoulder, the middle deltoid, the biceps brachii, the triceps brachii, the brachioradialis, and the flexor carpi ulnaris were significantly higher than the stable state. In addition, the muscle activity in the sections of mixing the soil, filling the tray with the soil, sowing, writing the label, and watering was significantly higher than the stable state. In particular, the muscle activity of the biceps brachii and the triceps brachii was statistically significantly high in the section of filling the tray with the soil, which indicates that the task of filling the tray with the soil can be utilized as an exercise to activate the biceps brachii and the triceps brachii. In addition, the muscle activity of the brachioradialis was significantly high in all the work sections, which indicates that the sowing process can be utilized to exercise the brachioradialis in particular. These results can be used as the basic data about the activated muscle types and degrees throughout the sowing process. These results can be also used to induce the activation of specific muscles, and the overall exercise and rehabilitation of the forearms.
        31.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        최근 다엽콜리메이터를 부착한 선형가속기를 이용한 방사선수술의 빈도가 점차 높아지고 있다. 이러한 정교한 방사선 수술은 소조사면 내에 고선량의 방사선이 집중적으로 조사되기 때문에 체계적이고 정확한 정도관리가 필수적이다. 본 연구는 PIB(Particle in Binder) 방식 중 침전법을 이용하여 400 ㎛ 두께의 요오드화납(PbI2)과 요오드화수은(HgI2) 광도전체 센서 시편를 제작하였다. 제작된 시편의 전기적 특성은 암전류, 출력전류, 응답특성 및 선형성을 평가하였다. 평가 결과, HgI2 가 우수한 신호발생량과 선형성을 보였다. 끝으로, 두께에 따른 HgI2 센서의 신호반응 특성 결과, 400 ㎛ 두께에서 신호발생효율이 가장 높았고, ±2.5 % 이내의 우수한 재현성을 보였다.
        32.
        2016.10 서비스 종료(열람 제한)
        Background : Most of cases in korea, distributed herbal medications are storaged in room temperature and it causes many insect pests during storage. Despite the fact, there is little research about storage conditions. Temperature and humidity in storehouse are highly related with pests’ overwintering, generation length and the number of occurrence in summer. Consequently, in this research, major pests’ overwintering was studied by reviewing facility condition, temperature and humidity in major regional storehouses. The results of this would help to develop how to manage pest occurrence in distributed herbal medications. Methods and Results : For this study, storage facilities was investigated at different regions including Gyeongdong Market in Seoul, the pharmaceutical company in Daegu and farmhouse in Youngcheon by monitering temperature, humidity, ventilator, air conditioning and heating on ground and underground places from June 2014 to July 2016. including Upon investigation, most of building using for storage had simple ventilators. Whereas in case of farmhouse, it is vulnerable to maintaining quality. Because most farmhouse had temporary buildings which are difficult to control temperature and humidity. In addition, among the other surveyed warehouses, Basement in the Gyeongdong Market had most favorable condition for pest overwintering. The lowest temperature of it was seldom below zero maintaining level of about 1.5℃ and average temperature was about 10℃ in underground warehouse during winter. And the ground warehouse of Daegu had similar patterns in temperature and humidity with that of Seoul in that being over 0℃ even in the winter. In Youngcheon, the temperature of farmhouse was below zero degree and the daily range of temperature and humidity was wide. It caused difficulty of overwintering of insect pests but possible to inhabit. Conclusion : According to a study by Han-Mo, Koo(1997), it was impossible to overwinter for Lasioderma serricorne F. which is dominant medicinal plants’ pest in north of the Chungcheong region’s warehouse due to low temperature. But in case of investigated warehouses, it was possible to overwinter because of the high temperature in office building or basement storage area. In order to make prediction of pest occurrence and comprehensive measures, it is urgent to take more investigation by regional groups and types of storage.
        33.
        2016.05 서비스 종료(열람 제한)
        Background : This study was development of moisture tolerance and high-yielding Rehmannia glutinosa cultivar. Methods and Results : Segang is developed by the medicinal crop breeding team of National Institute of Horticulture and Herbal Science(NIHHS), Rural Development Administration(RDA), during the period from 2005 to 2015. The reproduction of Rehmannia glutinosa has been accomplished mainly by vegetative propagation with its seedlings have many variants. The cultivar was selected from seedling of Jihwang 1(check variety). The plant type of Segang is some rising from ground. Regional yield trials conducted at three site from 2014 to 2015. The root yield of Segang was 21.1ton per hectare, which was increased 12% compared with Jihwang 1. Also, Segang has higher catalpol content and dried root ratio compared with Jihwang 1. Conclusion : Segang is a moisture tolerance and high-yielding Rehmannia glutinosa cultivar.
        34.
        2015.09 서비스 종료(열람 제한)
        Left ventricular (LV) thrombi may be caused by various conditions, particularly myocardial infarction. In most cases, LV thrombus occurs in patients with a significantly reduced ejection fraction. A LV thrombus is extremely rare in patients with normal LV function. We report a case of LV thrombus initially detected on transthoracic echocardiography and confirmed using cardiac magnetic resonance imaging in a patient with normal LV wall motion. We highlight the rarity of this condition and the usefulness of cardiac magnetic resonance imaging in the diagnosis of LV thrombus.
        35.
        2015.09 서비스 종료(열람 제한)
        Hepatocytes and hepatic progenitors derived from human ES cells may be a useful source for clinical application. Therefore, identification and purification of these cell types would be following important issues. There are very few candidate surface markers that can be used to identify and purify hepatic progenitor cells. In addition, indocyanine-green can be uptaken by mature hepatocytes, but cannot be applied for fluorescence activated cell sorting (FACS) due to its long emission wavelength. In the present study, we tested EpCAM as a potential marker for magnetic-activated cell sorting (MACS) of hepatic progenitors and also modified indocyanine-green into fluorescent indomonocarbocyanine for FACS-mediated sorting of mature hepatocytes after differentiation of human ES cells. Hepatic progenitor cells were sorted by MACS after incubation with anti-human EpCAM antibodies. After the final differentiation, the differentiated cells and mouse primary hepatocytes (control group) were incubated with indomonocarbocyanine and were sorted by FACS. MACS and immunocytochemistry data showed that approximately 45% of differentiated cells were EpCAM-positive cells. EpCAM-positive cells expressed α-fetoprotein, FOXa2, HnF4a, and CK18. Differentiation efficiency into albumin-positive cells was significantly higher in EpCAM-positive cells, compared to EpCAM-negative cells. Importantly, indomonocarbocyanine successfully stained cells that expressed ALB. Furthermore, FACS analysis data showed that the purity of hepatocytes that expressed albumin was significantly increased after purification of indomonocarbocyanine-positive cells. Our data demonstrated that human ES cell-derived hepatic progenitors can be efficiently isolated by MACS using EpCAM antibody. In addition, we also showed that indomonocarbocyanine can be successfully used to identify and purify mature hepatocytes using FACS.
        36.
        2015.09 서비스 종료(열람 제한)
        Highly homogeneous and functional stem cell-derived hepatocyte-like cells (HLCs) are considered a promising option in the treatment of liver disease and the development of effective in vitro toxicity screening tool. However, the purity of cells and expression and/or activity of drug metabolizing enzymes in stem cell-derived HLCs are usually too low to be useful for clinical or in vitro applications. Here, we describe a highly optimized differentiation protocol, which produces more than 90% albumin-positive HLCs with no purification process. In addition, we show that hepatic enzyme gene expressions and activities were significantly improved by generating three-dimensional (3D) spheroidal aggregate of HLCs. The 3D differentiation method increased expressions of nuclear receptors that regulate the proper expression of key hepatic enzymes. Furthermore, a significantly increased hepatic functions such as albumin and urea secretion were observed in 3D hepatic spheroids and HLCs in the spheroid exhibited morphological and ultrastructural features of normal hepatocytes. Importantly, we show that repeated exposures to xenobiotics facilitated the functional maturation of HLC, as confirmed by increased expression of genes for drug metabolizing enzymes and transcription factors. In conclusion, the 3D culture system with repeated exposures to xenobiotics may be a new strategy for enhancing hepatic maturation of stem cell-derived HLCs as a cell source for in vitro high-throughput hepatotoxicity models.
        37.
        2015.09 서비스 종료(열람 제한)
        Hepatocyte-like cells (HLCs) derived from human pluripotent stem cells have received extensive attention in the development of drug screening and toxicity testing. However, it has been reported that stem cell-derived HLCs showed hepatic functions that were too limited to be of use in drug screening and toxicity testing, possibly due to the lack of sufficient intercellular communication under conventional two-dimensional (2D) culture conditions. Therefore, a 3D differentiation system may overcome the in vitro limitation of 2D culture to produce stem cell-derived hepatocytes with mature metabolic functions. In this study, the feasibility of using a silicone-based spherofilm, specifically designed to produce spherical cell clusters, to generate uniformly sized 3D hepatic spheroids from hESCs was investigated. Hepatic spheroids generated on the spherofilm showed more homogenous size and shape than those generated in conventional low-attachment suspension culture dishes. Results of immunohistochemical analysis showed that expression of the mature hepatic marker albumin (ALB) increased over time during the hepatic maturation process. Furthermore, the 3D culture system mimicked the in vivo 3D microenvironment. Laminin, which is an important component of hepatic ECM, was expressed in hepatic spheroids. The results of immunohistochemical analysis indicated that the 3D culture environment is capable of generating an in vivo-like microenvironment. In addition, quantitative PCR analysis showed that the mature hepatic marker ALB and cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A7 were expressed at higher levels in 3D culture than in 2D culture. This indicates that the 3D culture system is suitable for hepatic maturation and that our size-controlled 3D culture conditions might accelerate hepatic function. These results suggest that 3D hepatic spheroids significantly enhance metabolic maturation of hepatocytes derived from hESCs
        38.
        2015.02 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate the effects of the Cirsium japonicum var. ussuriense (C. japonicum)extract on serum level of hormones from induced osteoporosis by ovariectomized rats. Two month-old rats were ovariecto-mized (OVX), remained untreated for 8 weeks, and were subsequently administered C. japonicum (200㎎/㎏) every day for8 weeks. We examined the effects of treated C. japonicum on ovariectomy-related changes in Insulin-like Growth Factors(IGF), Insulin-like Growth Factor binding protein-3 (IGBF-3), Estrogen, Calcium, and Phosporus. After 8 weeks, the serumlevels of IGF-I, -II, and IGFBP-3 were higher presented as compared to the other two groups (P<0.05), in the C. japonicumextract treatment on OVX rats. There were differences between OVX and C. japonicum extract treated OVX rats in serumlevels of Ca2+, but Ca2+ levels for the normal group was higher than for the other two groups. The C. japonicum extractincreased both serum IGFs and IGFBP-3 levels on induced osteoporotic rat by ovariectomized. Thus, these results revealedthat the C. japonicum extract is a possible role for improvement of osteoporosis induced-ovariectomized rats and has a greatpotential as an alternative tool for the treatment of osteoporosis.
        39.
        2014.07 서비스 종료(열람 제한)
        Gliadins are the main class of wheat seed storage proteins. Since gliadins show a high level of polymorphism as well as genetically fixed, it can be used as a marker for the genetic identification. Gliadin subunit diversity information can be useful for wheat quality breeding programs. Tunisia is a country in the North Africa bordered with the Mediterranean Sea to the north and the east but with the Sahara desert to the south, which represent extremely different growth climate. Therefore, there may be a numerous variation in Tunisian common wheat and durum wheat. Total 48 lines of wheat consisted of 32 common wheat (16 Korean wheat and 16 Tunisian common wheat) and 16 Tunisian durum wheat were incorporated in this study. Gliadins were extracted with 70% ethanol and fractionated by acid polyacrylamide gel electrophoresis (A-PAGE) at 8% in aluminum lactate buffer (pH 3.1). The gel was stained with 0.25% Coomassie Brilliant Blue (CBB) R-250. The presence of each gliadin subunit band was scored and cluster analysis was carried out. The cluster showed that wheat varieties were classified into some groups and their genetic distance could be identified. The obtained information will be helpful to the future breeding program of tetraploid durum wheat as well as hexaploid common wheats. Acknowledgement: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2012K1A3A1A09028123) and carried out with the support of “Cooperative Research Program for Agriculture Science & Technology Development (Project title: Development of high yielding wheat with stress tolerance via molecular breeding strategies, Project No. PJ008031)”, Rural Development Administration, Republic of Korea.
        40.
        2013.08 서비스 종료(열람 제한)
        MFG-E8 (Milk fat globule-epidermal growth factor VIII), also called lactadherin or BA46, SED1 is a glycoprotein found in milk and mammary epithelial cells, it is a major protein component associated with milk fat globule membrane. Previously, our study showed that expression of MFG-E8 is gradually increased with hepatic differentiation of human embryonic stem cells (hESCs). Therefore, we hypothesized that MFG-E8 would be an early cancer stem cell marker, which may predict cancer progression. Our results showed that MFG-E8 was expressed in various human cancer cell lines such as HepG2, Hep3B, and Huh7. Production and secretion of the MFG-E8 were also confirmed in the conditioned media of those three cell lines using enzyme-linked immunosorbent assay. Next, we analyzed the MFG-E8 expression in 11 clinical cases of cholangiocellular carcinoma (CC) and 33 cases of hepatocellular carcinoma (HCC) by immunohistochemistry and examined the potential correlation with β-catenin and AFP, which are known cancer markers. According to hitological criteria, the progression of HCC and CC was evaluated and classified into high, low, metastatic, and well-, moderate-, poor-differentiated, respectively. Statistical analysis indicated that incidence of both HCC and CC is significantly associated with male compared to female (P<0.05). Tumor size also has positive correlation with age (r2=08948). Our immunohistochemistry data showed that MFG-E8 was expressed both HCC and CC tissue. Interestingly, the MFG-E8 expression was significantly increased with cancer progression (P<0.05) in both cases. Additionally, b-cateninexpression was increased and its localization was changed from membrane to cytoplasm and nucleus with the degree of HCC. Likely b-catenin, AFP was also increased with the degree of HCC but it was not correlated with severalty of CC. Importantly, both AFP and b-catenin were highly co-localized with MFG-E8 in HCC. These results suggest that MFG-E8 may have important physiological roles and its expression in HCC and CC would be considered as an important prognostic factor.
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