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      • Platycodon grandiflorum root-derived saponins attenuate atopic dermatitis-like skin lesions via suppression of NF-kB and STAT1 and activation of Nrf2/ARE-mediated heme oxygenase-1

        ( Jae Ho Choi ),( Sun Woo Jin ),( Eun Hee Han ),( Bong Hwan Park ),( Hyung Gyun Kim ),( Tilak Khanal ),( Yong Pil Hwang ),( Minh Truong Do ),( Hyun Sun Lee ),( Young Chul Chung ),( Hee Suk Kim ),( Tae 영남대학교 약품개발연구소 2014 영남대학교 약품개발연구소 연구업적집 Vol.24 No.0

        Purpose: The consequences of precipitously rising allergic skin inflammation rates worldwide have accelerated the risk of atopic dermatitis (AD). Natural product-based agents with good efficacy and low risk of side effects offer promising prevention and treatment strategies for inflammation-related diseases. We have already reported that Platycodon grandiflorum root-derived saponins (Changkil saponins, CKS) have many pharmacological effects, including anti-inflammatory and anti-allergic effects, but its influence on AD remains unclear. Therefore, we evaluated the inhibitory effect of CKS, mainly platycodin D, on AD-like skin symptoms in mice and the possible mechanisms in cells. Methods: Mice were sensitized and challenged with 2,4-dinitrochlorobenzene (DNCB). Four weeks after challenge, mice were treated with oral administration of CKS for 4 weeks. In addition, cells were used to evaluate the effect of CKS, mainly platycodin D, on the TARC expression regulated mechanism. Results: CKS attenuated DNCB-induced dermatitis severity, serum levels of IgE and TARC, and mRNA expression of TARC, TNF-α, IFN-γ, IL-4, IL-5, and IL-13 in mice. Histopathological examination showed reduced thickness of the epidermis/dermis and dermal infiltration of inflammatory cells and mast cells in the ears. Moreover, CKS and platycodin D inhibited TNF-α/IFN-γ-induced TARC expression through the suppression of NF-κB and STAT1 and induction of Nrf2/ARE-mediated hemeoxygenase-1 (HO-1) expression in cells. Conclusion: We suggest that CKS and platycodin D inhibited the development of AD-like skin symptoms by regulating cytokine mediators and may be an effective alternative therapy for AD-like skin symptoms.ⓒ2014 Elsevler Gmbh. All rights reserved.

      • KCI등재후보
      • PSC 교량의 보강공법에 대한 실험적 연구

        김현호,김기봉,정인근,송재필 中央大學校 建設環境硏究所 2002 環境科學硏究 Vol.13 No.2

        많은 수의 국도상의 교량이 교통량 증가 및 차량의 대형화에 따라 내하력 증가의 필요성이 시급히 제기되고 있다. 본 연구에서는 국도상 교량 중 대다수를 차지하고 있는 프리스트레스트 콘크리트(Prestressed Concrete, PSC) 교량에 대해 유리섬유 부착 공법과 외부 후긴장 보강 공법을 적용하여 내구성 및 내하력의 증가방안을 확인하고자 한다. 실험체는 표준도면의 1/5 축소모델로서 지간길이 6m이며 총 15개의 실험체를 제작하여 정적 및 피로실험을 수행하였다. 실험 결과, 유리섬유 및 외부 후긴장 보강 방법을 적용하였을 때 균열하중 및 파괴하중의 크기가 증가되었고, 처짐의 감소효과와 균열에 대한 억제 능력이 증가하였다. 그리고 보강 실험체가 피로파괴 반복회수도 증가하며 유리섬유 보강 실험체의 경우 외부 후긴장 실험체보다 피로성능이 더 우수한 것으로 나타났다. 본 연구 결과를 통해 적용된 보강 기법이 노후된 PCS 교량의 성능증가와 수명 연장의 효과가 큰 것을 확인하였다. Most of the bridges on national road are needed capacity-enhancement, because of the increase of heavy traffic loads and aging of bridges. Among those bridges, prestressed concrete(PSC) bridges take a large portion. But there are not many related researches about strengthening PSC bridges. In this study, the practicability of strengthening methods for PSC beam were studied by the static and fatigue experimental method. For the experiment, 1/5 scale and six meters long PSC beams were made with concrete slabs. Glass fiber sheeting and external post-tensioning methods were used for strengthening PSC beams. Total 15 beams were made for static test and fatigue test. As a result, the strengthening methods, which used in this study, are efficient at increasing cracking load and failure load, to decrease deflection and prevent cracks. The experimental results show that the failure cycle of strengthened members are increased compare to non-strengthened members. The members strengthened with glass fiber show better enhancement in fatigue problem than the members strengthened with external post-tensioning method. With these experimental results, it can be said that the strengthening methods used in this study are efficient at extending the life time of aged PSC bridges.

      • KCI등재

        금산지역의 수삼의 저장관리 및 유통 현황

        김현호,황용수,성봉재,김선익,조진웅,김충수 충남대학교 농업과학연구소 2006 농업과학연구 Vol.33 No.2

        There are need to develop of merchandise of value added fresh ginseng because of high consciousness level of consumer and enlarge of markets for high quality products. The fresh ginseng after harvest was distributed to farmer partually but in general, it was to market by consigner or wholsaler directly after harvest. There were a high difference on storage period of fresh ginseng in different harvesting seasons. The reduction of value of commodities of fresh ginseng for storage period was caused by decomposition and tender of tissue. The storage temperature was under the freezing point and the packing method was sealing tightly by plastic film. As the quality of fresh ginseng was defined by naked eye, it was difficult to sort the quality of ginseng directly harvest.

      • 실리콘의 TMAH 식각을 사용한 Suspended-type 마이크로 가스센서의 제조

        김현호,이상문,임준우,강봉휘,정완영,이덕동 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

        In recent years, different types of microfabricated 'suspended-type' structure have been used as freestanding membranes for a variety of micro gas sensors. We examined the silicon etching characteristics of tetramethyl ammonium hydroxide(TMAH). A suspended type micro gas sensor with platinum heater, sensing electrode and temperature sensor using TMAH etching of silicon was fabricated on silicon nitride(1,500Å)/ silicon dioxide (3,000Å)/ silicon nitride(1,500Å) dielectric membrane. It has low thermal conductivity and balanced stress with silicon substrate for the purpose of improving the thermal isolation between heater and silicon substrate. To avoid any chemical or physical damages to gas sensing material during the photolithography or shadow mask process, the tin dioxide film was deposited onto whole surface of device by using maskless electron beam(e-beam) evaporation technology. The power consumption of the fabricated device was about 40mW at the operating temperature of 250°C. In case of adding Pt(2wt.%) or Pd(2wt.%) catalyst, the sensitivity to CO was higher and the sensitivity to C_(4)H_(10) was higher than those to other gases, respectively.

      • LMC로 덧씌우기 보수된 RC보의 계면응력에 관한 연구

        김현오,김성환,김동호,이봉학 江原大學校 産業技術硏究所 2004 産業技術硏究 Vol.24 No.A

        Each year, new technological advancements for repair-purpose are being introduced to overlay the old deterioration of RC bridge deck at highway by latex-modified concrete. The days may come when this old problem will be successfully resolved. While the experimental works and researches are very active at both laboratory and field, only a few theoretical studies were performed on interfacial problems, especially on stress distribution and concentration of RC beam overlayed by latex-modified concrete. The repaired and strengthened structures would induce a premature failure due to the stress concentration at the adhesive layer of different material before the design expected failure. This paper investigated and proposed an analytical model for predicting interfacial shear and normal stresses of RC beam repair-purpose overlayed by latex-modified concrete. This would be used for predicting interfacial stresses and preventing premature failure at interfaces. This study modified Smith-Teng method for applying to cementitious repairing material, which was based on a direct governing equation and linear-elastic approach for interfacial normal and shear stresses. The proposed theoretical model was verified using commercial FEA program, LUSAS, in terms of interfacial stresses predicted by the proposed model and calculated by LUSAS.

      • 유리섬유로 전단보강된 철근콘크리트 보의 거동에 관한 실험적 연구

        김기봉,정영수,김현호 中央大學校 建設環境硏究所 1999 環境科學硏究 Vol.9 No.2

        Recently, glassfibers have been used for strengthening in RC structures because of low material cost and easy repairing work. The purpose of this study is to experimentally and analytically investigate the effect of glassfibers for enhancing the shear capacity of RC beams. The experimental result shows that ultimate strength of RC beams with glassfibers are increased up to 34% comparing with those for RC beams without glassfibers. Also, ductility of RC beams strengthened with glassfibers have been significantly increased. It had been observed from the test that fatigue behaviours of RC beams with glassfibers have been significantly improved by comparing with those for RC beams without glassfibers.

      • 조사연구에서 표본설계에 대한 고찰

        양철호,양선화,신봉관,조지현 동신대학교 2005 論文集 Vol.15 No.-

        Most of the survey research are conducted with samples. Thus, representativeness of the samples is crucial for the sound research. Reports of the various survey research were analized. The results of the analysis showed that different ways of sampling methods were utilized in various studies in order to ensure the selection of unbiased samples under the circumstances of purpose and population of the survey.

      • KCI등재
      • 노화가 인체 중간엽 줄기세포로부터 조골세포로의 증식 및 분화에 미치는 영향

        백기현,태현정,오기원,이원영,조정기,권순용,강무일,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

        연구배경: 일반적으로 골다공증과 연관된 위험인자로는 연령, 폐경, 약물, 불충분한 칼슘섭취, 만성질환 및 운동부족 등이 있는데, 특히 노화가 진행할수록 골밀도가 감소하는 것은 잘 알려져 있다. 노화와 관련하여 진행되는 골소실은 조골세포 및 전구조골세포의 기능적 결핍에 의한 골형성의 감소가 주요한 요인으로 여겨지고 있다. 그 동안 연령이 조골모 세포의 양과 조골모 세포로부터 성숙조골세포로의 분화 및 증식에 미치는 영향에 대한 일부 보고들이 있었으나 아직 일치된 견해는 없는 형편이다. 방법: 다양한 연령의 사람으로부터 골수를 채취, 중간엽 줄기세포가 포함된 단핵세포를 분리한 후 조골세포로 분화하기 좋은 조건하에서 배양하였다. 대상군은다시 젊은군과 노령군으로 구분하여 다양한 변수를 비교 분석하였다. 일차배양에서는 CFU-F를 계수하여 골수내 중간엽 줄기세포의 수를 추산하였고, 칼슘측정을 통하여 기질의 무기화 정도를 비교하였다. 계대배양후 이차배양에서는 시기별로 알카리성 포스파타제 활성도를 측정하고 오스테오칼신 mRNA의 발현을 관찰하여 젊은군과 노령군 사이의 증식능 차이를 비교하였다. 또한 이차배양 시기별로 MTT 측정을 하여 양군간에 증식능 차이가 있는지 알아보았다. 결과: 1. 일차배양 15일째에 평균 CFU-F의 수는 젊은군에서 유의하게 많았다(젊은군 148.3±28.9, 노령군 54.3±9.1, p=0.02). CFU-F의 평균면적은 젊은군에서 넓은 경향을 보였으나 통계적으로 유의하지는 않았다. 2. 일차배양 17일 경과 후 양군간에 기질 칼슘 침착정도는 유의한 차이를 보이지 않았다(젊은군 103.6±50.6, 노령군: 114.0±56.5, p=NS). 3. 이차배양 10일째에 젊은군에서 알카리성 포스파타제 활성도가 고령군에 비해 유의하게 높았다(젊은군: 935.5±115.0 U/mg, 노령군: 578.4±115.7U/mg,p.0.05). 고령군에서는 시간 경과에 따른 변화가 미약했으며 전반적으로 알카리성 포스파타제의 활성도가 젊은군에 비해 낮았다. 4. 이차배양도중 오스테오칼신 mRNA의 발현은 배양시기별로 젊은군에 비해 고령군에서 더 낮은 경향을 관찰할 수 있었다. 5. 이차배양 10일과 15일에 젊은군에서 노령군보다세포증식이 유의하게 증가된 양상을 보였다(10앓 젊은군 0.73±0.05, 노령군 0.58±0.04, p=0.05, 15일; 젊은군 0.80±0.05, 노령군 0.70±0.03, p=0.05).결론: 이상의 연구에서 저자들은 노령군에서 젊은군보다 골수 내 중간엽줄기세포의 수가 적고, 노령군에서 유래한 전구조골세포의 성숙조골세포로의 증식 및 분화가 젊은군 보다 감소해 있는 것을 관찰할 수 있었다. Background: Osteoblasts originate from osteoprogenitor cells in bone marrow stroma, termed mesenchymal stem cells (MSCs) or bone marrow stromal cells. Each MSC forms colonies (colony forming units-fibroblasts [CFL-Fs]) when cultured ex vivo. There are some reports about the age-related changes of the number and osteogenic potential of osteoprogenitor cells, but any relationship has not been clearly established in humans. In this study, we counted MSCs using CFU-Fs count and examined the proliferative capacity and differentiation potential of osteoprogenitor cells. Finally, we analyzed how these parameters varied with donor age. Methods: Bone marrow was obtained from the iliac crest of young (n=6, 27.2±8.6 years old) and old (n= 10, 57.4k6.7 years old) healthy donors. Mononuclear cells, including MSCs, were isolated and cultured in osteogenic medium. In primary culture, we compared the colony-forming efficiency of MSCs between the two groups and determined the matrix calcification. When primary culture showed near confluence, the cells were subcultured. Alkaline phosphatase activity, osteocalcin expression by RT-PCR and proliferative potential by MTT assay were examined by the time course of secondary culture. Results: At the 15th day of primary culture, the mean number of CFU-Fs was significantly higher in the younger donors (young: 148.3±28.9, old: 54.3±9.1, p=0.02) and the mean size of CFL-Fs was also larger in the younger donors than the older donors. However, matrix calcification was not different between the two groups (young: 103.6±50.6, old: 114.0±56.5, p=NS). In secondary culture, alkaline phosphatase activities were significantly lower in the older donors. The younger donors showed peak alkaline phosphatase activity at day 10, while the older donors didn't showed a remarkable peak (young: 935.5±115.OU/mg, old: 578.4±115.7U/mg, p<0.05). Total cell number as a proliferative index increased progressively during the secondary culture and a significantly greater cell number was noted in the younger donors. Osteocalcin expression was generally upregulated in the younger donors, but this was not statistically significant. Conclusion: Our study shows that the number of osteoprogenitor cells is decreased during aging and that the proliferative capacity and differentiation potential of osteoprogenitor cells seem to be reduced during aging (J Kor SOC Endocrinol 18:296-305, 2003).

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