• 제목/요약/키워드: $J_c$ (B)

검색결과 5,396건 처리시간 0.032초

산소분압에 따른 Fe-Sm-O계 박막의 연자기적 성질 (The Influence of $O_2$ Partial Pressure on Soft Magnetic Properties of As-deposited Fe-Sm-O Thin Films)

  • 윤대식;조완식;고은수;이영;박종봉;김종오
    • 한국재료학회지
    • /
    • 제10권11호
    • /
    • pp.755-759
    • /
    • 2000
  • RF magnetron sputtering법으로 초미세결정 Fe-Sm-O계의 박막을 상온에서 제작하여 산소분압에 따른 포화자화, 보자력, 고주파에서의 투자율(100MHz)을 조사하였다. 최적조건인 5%의 산소분압에서 제조한 초미세결정 Fe(sub)83.4Sm(sub)3.4O(sub)13.2박막은 포화자속밀도 18kG, 보자력 0.82 Oe, 실효투자율 (0.5~100MHz) 2,600 이상의 우수한 연자성을 나타내었다. 산소분압이 증가함에 따라 $\alpha$-Fe 결정립의 크기가 감소하여 10%이상의 산소분압에서는 FeO가 생성되어 연자기적 성질이 열화되었다. Fe-Sm-O계 박막의 전기비저항은 산소분압이 증가함에 따라 증가하는 경향을 나타내었으며 우수한 연자기적 성질을 가지는 Fe(sub)83.4Sm(sub)3.4O(sub)13.2박막의 경우, 전기비저항은 130 $\mu$$\Omega$cm이었다. 따라서 미세하게 형성된 $\alpha$-Fe 결정립과 높은 전기비저항 때문에 초미세결정 Fe(sub)83.4Sm(sub)3.4O(sub)13.2박막이 고주파에서 우수한 연자기적 성질을 가지는 것으로 판단된다.

  • PDF

열적으로 안정한 금나노입자를 이용한 블록공중합체 내에서의 입자위치 조절 (Controlling the Location of Thermally Stable Au Nanoparticles with Tailored Surface Property within Block Copolymer Templates)

  • 김세용;유미상;정세라;백관열;김범준;방준하
    • 폴리머
    • /
    • 제35권3호
    • /
    • pp.238-243
    • /
    • 2011
  • 유기/무기 혼합 물질은 뛰어난 성능으로 인해 지난 수년간 다양한 분야에서 많은 관심을 받고 있다. 고분자 매트릭스에서의 무기 나노입자의 위치 및 분산을 조절하기 위해 싸이올(-SH) 기능기로 말단이 치환된 고분자 리간드가 나노입자의 표면 성질을 개질하는 데에 많이 사용되고 있다. 그러나 싸이올 기능기와 금속 나노입자간의 특정한 결합은 높은 온도에서는 매우 불안정하다. 본 연구진은 UV 경화가 가능한 azide 그룹을 고분자 리간드에 도입하여 열적으로 매우 안정한 금나노입자를 합성하여 보고한 바 있다. 본 연구에서는 더 나아가 표면 성질이 개질된 열적으로 안정한 금나노입자를 얻기 위해서 상대적으로 극성인 UV 경화 가능한 azide와 무극성인 스티렌의 공급 몰 비를 각각 다르게 해서 다양한 UV 경화성 고분자 리간드를 합성하였다. 이를 이용해 합성한 금나노입자는 열적으로 매우 안정하였으며 PS-b-PMMA와 같은 블록공중합체 매트릭스 내에서 금나노입자의 위치를 한 도메인에서 계면으로 정교하게 조절 할 수 있음을 확인하였다.

위탁급식전문업체 지적자본 측정도구의 운용시험 평가 (Practical Evaluation of Intellectual Capital (IC) Measurement Tool for Contract Foodservice Management Company)

  • 박문경;양일선
    • Journal of Nutrition and Health
    • /
    • 제38권10호
    • /
    • pp.880-894
    • /
    • 2005
  • The purposes of this study were to a) measure the IC identified of CFMC (contract foodservice management company) ,b) examine IC circumstance of CFMC, c) evaluate practically IC measurement tool of CFMC, and d) present information for selecting an adequate CFMC to clients. The questionnaires of IC measurement were handed out to 108 CFMCs, there composing of main office employees, foodservice managers, customers, and clients of 207 school,38 hospital, and 86 husiness/industry foodservices. The statistical data analysis was completed using SPSS Win (ver 12.0) for descriptive analysis, t-test, Mann-Whitney U test. First, CFMCs had operational experience for an average of 8 years and 8 months, and served an average of 38,540 meals a day. Most of the respondent companies specialized in the school foodservice field and managed an average of 66 clients for the contract period of 2 years and 3 months. Second, the respondent companies had gotten a score of 77.78 points for the total average, 77.7 points in the large enterprise group and 78.1 points in the small and medium-sized enterprise group. Therefore, the minimum number of points for the accrediting license on Qualification is suggested to be over 70 out of a 100 point scale; this study would be serve as reference for the certification license on qualification. On the level of evaluation category, the scores were 14.15 to 20 points on $\ulcorner$finance$\urcorner$, 19.24 to 25 points on $\ulcorner$customer$\urcorner$, 19.33 to 25 points on $\ulcorner$process$\urcorner$, 14.31 to 20 points on $\ulcorner$human resource$\urcorner$, and 8.6 to 10 point on $\ulcorner$renewal and development$\urcorner$ . $\ulcorner$Renewal and development$\urcorner$ and $\ulcorner$customer focus$\urcorner$ received better grades than other evaluation categories. Third, $\ulcorner$Finance$\urcorner$ indicated similar distribution overall. Small and medium-sized companies had lower grades than large companies on 'market ability' of $\ulcorner$customer$\urcorner$ , but, clients of small and medium-sized companies had higher grade for 'client satisfaction' than large companies. Most of the companies supported 'infrastructure support for foodservice operation' of $\ulcorner$process$\urcorner$ by the main office of CFMCs, but, the branch chain offices of CFMCs were not applied efficiently. Large companies made more effort to improve the 'employee ability' of $\ulcorner$human focus$\urcorner$ than small and medium-sized CFMC. The 'research and development cost' of $\ulcorner$renewal and development$\urcorner$ was increased compared to the previous year. In conclusion, if CFMCs were to perform self-evaluation and a routine checkups by utilizing CFMC's IC measuring tool, improvements in CFMC operational capacities as well as foodservice quality can be noted. (Korean J Nutrition 38(10)'880$\sim$894,2005)

Molecular mechanism of protopanaxadiol saponin fraction-mediated anti-inflammatory actions

  • Yang, Yanyan;Lee, Jongsung;Rhee, Man Hee;Yu, Tao;Baek, Kwang-Soo;Sung, Nak Yoon;Kim, Yong;Yoon, Keejung;Kim, Ji Hye;Kwak, Yi-Seong;Hong, Sungyoul;Kim, Jong-Hoon;Cho, Jae Youl
    • Journal of Ginseng Research
    • /
    • 제39권1호
    • /
    • pp.61-68
    • /
    • 2015
  • Background: Korean Red Ginseng (KRG) is a representative traditional herbal medicine with many different pharmacological properties including anticancer, anti-atherosclerosis, anti-diabetes, and anti-inflammatory activities. Only a few studies have explored the molecular mechanism of KRG-mediated anti-inflammatory activity. Methods: We investigated the anti-inflammatory mechanisms of the protopanaxadiol saponin fraction (PPD-SF) of KRG using in vitro and in vivo inflammatory models. Results: PPD-SF dose-dependently diminished the release of inflammatory mediators [nitric oxide (NO), tumor necrosis factor-${\alpha}$, and prostaglandin $E_2$], and downregulated the mRNA expression of their corresponding genes (inducible NO synthase, tumor necrosis factor-${\alpha}$, and cyclooxygenase-2), without altering cell viability. The PPD-SF-mediated suppression of these events appeared to be regulated by a blockade of p38, c-Jun N-terminal kinase (JNK), and TANK (TRAF family member-associated NF-kappa-B activator)-binding kinase 1 (TBK1), which are linked to the activation of activating transcription factor 2 (ATF2) and interferon regulatory transcription factor 3 (IRF3). Moreover, this fraction also ameliorated HCl/ethanol/-induced gastritis via suppression of phospho-JNK2 levels. Conclusion: These results strongly suggest that the anti-inflammatory action of PPD-SF could be mediated by a reduction in the activation of p38-, JNK2-, and TANK-binding-kinase-1-linked pathways and their corresponding transcription factors (ATF2 and IRF3).

Protective effect of Korean Red Ginseng against glucocorticoid-induced osteoporosis in vitro and in vivo

  • Kim, Jinhee;Lee, Hyejin;Kang, Ki Sung;Chun, Kwang-Hoon;Hwang, Gwi Seo
    • Journal of Ginseng Research
    • /
    • 제39권1호
    • /
    • pp.46-53
    • /
    • 2015
  • Background: Glucocorticoids (GCs) are commonly used in many chemotherapeutic protocols and play an important role in the normal regulation of bone remodeling. However, the prolonged use of GCs results in osteoporosis, which is partially due to apoptosis of osteoblasts and osteocytes. In this study, effects of Korean Red Ginseng (KRG) on GC-treated murine osteoblastic MC3T3-E1 cells and a GC-induced osteoporosis mouse model were investigated. Methods: MC3T3-E1 cells were exposed to dexamethasone (Dex) with or without KRG and cell viability was measured by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Realtime polymerase chain reaction was performed to evaluate the apoptotic gene expression; osteogenic gene expression and alkaline phosphatase (ALP) activity were also measured. Western blotting was performed to evaluate the mitogen-activated protein kinase (MAPK) proteins. A GC-induced osteoporosis animal model was used for in vivo study. Results and conclusion: The MTT assay revealed that Korean Red Ginseng (KRG) prevents loss of cell viability caused by Dex-induced apoptosis in MC3T3E1 cells. Real-time polymerase chain reaction data showed that groups treated with both Dex and KRG exhibited lower mRNA levels of caspase-3 and -9, whereas the mRNA levels of Bcl2, IAPs, and XIAP increased. Moreover, groups treated with both Dex and KRG demonstrated increased mRNA levels of ALP, RUNX2, and bone morphogenic proteins as well as increased ALP activity in MC3T3-E1 cells, compared to cells treated with Dex only. In addition, KRG increased protein kinase B (AKT) phosphorylation and decreased c-Jun N-terminal kinase (JNK) phosphorylation. Moreover, microcomputed tomography analysis of the femurs showed that GC implantation caused trabecular bone loss. However, a significant reduction of bone loss was observed in the KRG-treated group. These results suggest that the molecular mechanism of KRG in the GC-induced apoptosis may lead to the development of therapeutic strategies to prevent and/or delay osteoporosis.

1,2-Dichloropropane (1,2-DCP)-Induced Angiogenesis in Dermatitis

  • Jin, Meiying;Hong, Youngeun;Lee, Hyunji;Tran, Quangdon;Cho, Hyeonjeong;Kim, Minhee;Kwon, So Hee;Kang, Nak Heon;Park, Jisoo;Park, Jongsun
    • Toxicological Research
    • /
    • 제35권4호
    • /
    • pp.361-369
    • /
    • 2019
  • 1,2-Dichloropropane (1,2-DCP) has been used as an industrial solvent and a chemical intermediate, as well as in soil fumigants. Human exposure may occur during its production and industrial use. The target organs of 1,2-DCP are the eyes, respiratory system, liver, kidneys, central nervous system, and skin. Repeated or prolonged contact may cause skin sensitization. In this study, 1,2-DCP was dissolved in corn oil at 0, 2.73, 5.75, and 8.75 mL/kg. The skin of mice treated with 1,2-DCP was investigated using western blotting, hematoxylin and eosin staining, and immunohistochemistry. 1,2-DCP was applied to the dorsal skin and both ears of C57BL/6J mice. The thickness of ears and the epidermis increased significantly following treatment, and the appearance of blood vessels was observed in the dorsal skin. Additionally, the expression of vascular endothelial growth factor, which is tightly associated with neovascularization, increased significantly. The levels of protein kinase-B (PKB), phosphorylated PKB, mammalian target of rapamycin (mTOR), and phosphorylated mTOR, all of which are key components of the phosphoinositide 3-kinase/PKB/mTOR signaling pathway, were also enhanced. Taken together, 1,2-DCP induced angiogenesis in dermatitis through the PI3K/PKB/mTOR pathway in the skin.

Exposure to Particles and Nitrogen Dioxide Among Workers in the Stockholm Underground Train System

  • Plato, N.;Bigert, C.;Larsson, B.M.;Alderling, M.;Svartengren, M.;Gustavsson, P.
    • Safety and Health at Work
    • /
    • 제10권3호
    • /
    • pp.377-383
    • /
    • 2019
  • Objectives: Exposure to fine particles in urban air has been associated with a number of negative health effects. High levels of fine particles have been detected at underground stations in big cities. We investigated the exposure conditions in four occupational groups in the Stockholm underground train system to identify high-exposed groups and study variations in exposure. Methods: $PM_1$ and $PM_{2.5}$ were measured during three full work shifts on 44 underground workers. Fluctuations in exposure were monitored by a real-time particle monitoring instrument, pDR, DataRAM. Qualitative analysis of particle content was performed using inductively coupled plasma mass spectrometry. Nitrogen dioxide was measured using passive monitors. Results: For all underground workers, the geometric mean (GM) of $PM_1$ was $18{\mu}g/m^3$ and of $PM_{2.5}$ was $37{\mu}g/m^3$. The particle exposure was highest for cleaners/platform workers, and the GM of $PM_1$ was $31.6{\mu}g/m^3$ [geometric standard deviation (GSD), 1.6] and of $PM_{2.5}$ was $76.5{\mu}g/m^3$ (GSD, 1.3); the particle exposure was lowest for ticket sellers, and the GM of $PM_1$ was $4.9{\mu}g/m^3$ (GSD, 2.1) and of $PM_{2.5}$ was $9.3{\mu}g/m^3$ (GSD, 1.5). The $PM_1$ and $PM_{2.5}$ levels were five times higher in the underground system than at the street level, and the particles in the underground had high iron content. The train driver's nitrogen dioxide exposure level was $64.1{\mu}g/m^3$ (GSD, 1.5). Conclusions: Cleaners and other platform workers were statistically significantly more exposed to particles than train drivers or ticket sellers. Particle concentrations ($PM_{2.5}$) in the Stockholm underground system were within the same range as in the New York underground system but were much lower than in several older underground systems around the world.

Glycosyltransformation of ginsenoside Rh2 into two novel ginsenosides using recombinant glycosyltransferase from Lactobacillus rhamnosus and its in vitro applications

  • Wang, Dan-Dan;Kim, Yeon-Ju;Baek, Nam In;Mathiyalagan, Ramya;Wang, Chao;Jin, Yan;Xu, Xing Yue;Yang, Deok-Chun
    • Journal of Ginseng Research
    • /
    • 제45권1호
    • /
    • pp.48-57
    • /
    • 2021
  • Background: Ginsenoside Rh2 is well known for many pharmacological activities, such as anticancer, antidiabetes, antiinflammatory, and antiobesity properties. Glycosyltransferases (GTs) are ubiquitous enzymes present in nature and are widely used for the synthesis of oligosaccharides, polysaccharides, glycoconjugates, and novel derivatives. We aimed to synthesize new ginsenosides from Rh2 using the recombinant GT enzyme and investigate its cytotoxicity with diverse cell lines. Methods: We have used a GT gene with 1,224-bp gene sequence cloned from Lactobacillus rhamnosus (LRGT) and then expressed in Escherichia coli BL21 (DE3). The recombinant GT protein was purified and demonstrated to transform Rh2 into two novel ginsenosides, and they were characterized by nuclear magnetic resonance (NMR) techniques and evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay. Results: Two novel ginsenosides with an additional glucopyranosyl (6→1) and two additional glucopyranosyl (6→1) linked with the C-3 position of the substrate Rh2 were synthesized, respectively. Cell viability assay in the lung cancer (A549) cell line showed that glucosyl ginsenoside Rh2 inhibited cell viability more potently than ginsenoside Rg3 and Rh2 at a concentration of 10 μM. Furthermore, glucosyl ginsenoside Rh2 did not exhibit any cytotoxic effect in murine macrophage cells (RAW264.7), mouse embryo fibroblasts cells (3T3-L1), and skin cells (B16BL6) at a concentration of 10 μM compared with ginsenoside Rh2 and Rg3. Conclusion: This is the first report on the synthesis of two novel ginsenosides, namely, glucosyl ginsenoside Rh2 and diglucosyl ginsenoside Rh2 from Rh2 by using recombinant GT isolated from L. rhamnosus. Moreover, diglucosyl ginsenoside Rh2 might be a new candidate for treatment of inflammation, obesity, and skin whiting, and especially for anticancer.

세포질.유전자적 웅성불임 계통을 이용한 유채 Heterosis 육종에 관한 연구 제3보 유채 세포질 유전자적 웅성불임 계통의 불임안전성과 유.박의 성분 개량 (Studies on the Heterosis Breeding in Rape by Using Cytoplasmic Genetic Male Sterile lines 3. Development of Complete Cytoplasmic Genetic Male Sterile Line "MOKPO-MS" Having Improved Quality of Oil and Oil Cake)

  • 이정일;권병선
    • 한국작물학회지
    • /
    • 제25권3호
    • /
    • pp.50-58
    • /
    • 1980
  • 유채에서 $F_1$의 잡종강세를 이용함에 있어 Shiga나 Thmpson이 개발한 MS들은 고온에서 불임성이 회복되고 유질과 유박의 성분도 개량되지 못하였으므로 이같은 결점이 보완된 새로운 MS를 개발코저 연구를 계속한 결과 완전한 불임성이면서 에루친산과 구루코지노레이트가 제거, 개량된 새로운 세포질.유전자적 웅성불임계통 Mokpo-MS가 육성되었다. 이를 다음과 같이 요약한다. 1. Mokpo-MS는 캐나다 품종인 Tower를 어미로 하고 일본 품종 Isuzu를 화분친으로한 F_2에서 발견된 MS를 1입식 Q.C.T.법으로 Zero-erucic acid 개체를 선발하고 이를 Test-tape법으로 Zero-glucosinolate 개체를 재 선발하여 고정시켰다. MS유지는 임성인 자매개체, 계통의 화분으로 ,유지시켰다. 2. 세포질 유전자적 웅성불임계통 여부를 검정코저 Tower \times Isugu의 정역 조합을 작성하여 $F_2$에서 MS 분리비를 조사한 결과 Tower가 어미인 조합에서는 3 : 1의 비율로 MS가 분리되었으며 Tower가 화분친으로 된 조합에서는 전부 임성으로 발현되었으므로 Tower의 S세포질과 Isuzu의 핵내 S유전자와의 상호작용에 의해 발현되는 세포질 유전자적 웅성불임 계통임이 밝혀졌다.3. Mokpo-MS는 같은 계통내 임성인 개체의 화분으로 유지시키면 차대에서 각 50 %의 MS와 임성이 분리된다. 4. Moo-MS는 기존MS들 보다 2~3일 숙기가 빠르며 3~17개나 분지수가 더 많고 화기에서 웅예의 길이가 0.2mm 약장은 거의 없으며 상대적 위치가 0.0인 완전 MS였다. 5. 새로 육성된 Mokpo-MS의 유질은 바람직하지 못한 에루친산과 에이꼬젠산이 완전 제거되고 대신 양질 지방산인 오레인산과 리놀산 함량이 92%에 달하는 양질유 MS이다. 6. 유박의 사료화를 위한 성분개량에서도 유해물질인 Glucosinolate성분이 완전 제거되어 도입 대두박에 대체 가능하다. 7. Mokpo-MS는 화기의 불임성에 관계되는 형질이나 기타 생태적인 실용형질들이 완전히 인정되었다.

  • PDF

Respiratory protective effects of Korean Red Ginseng in a mouse model of particulate matter 4-induced airway inflammation

  • Won-Kyung Yang;Sung-Won Kim;Soo Hyun Youn;Sun Hee Hyun;Chang-Kyun Han;Yang-Chun Park;Young-Cheol Lee;Seung-Hyung Kim
    • Journal of Ginseng Research
    • /
    • 제47권1호
    • /
    • pp.81-88
    • /
    • 2023
  • Background: Air pollution has led to an increased exposure of all living organisms to fine dust. Therefore, research efforts are being made to devise preventive and therapeutic remedies against fine dust-induced chronic diseases. Methods: Research of the respiratory protective effects of KRG extract in a particulate matter (PM; aerodynamic diameter of <4 ㎛) plus diesel exhaust particle (DEP) (PM4+D)-induced airway inflammation model. Nitric oxide production, expression of pro-inflammatory mediators and cytokines, and IRAK-1, TAK-1, and MAPK pathways were examined in PM4-stimulated MH-S cells. BALB/c mice exposed to PM4+D mixture by intranasal tracheal injection three times a day for 12 days at 3 day intervals and KRGE were administered orally for 12 days. Histological of lung and trachea, and immune cell subtype analyses were performed. Expression of pro-inflammatory mediators and cytokines in bronchoalveolar lavage fluid (BALF) and lung were measured. Immunohistofluorescence staining for IRAK-1 localization in lung were also evaluated. Results: KRGE inhibited the production of nitric oxide, the expression of pro-inflammatory mediators and cytokines, and expression and phosphorylation of all downstream factors of NF-κB, including IRAK-1 and MAPK/AP1 pathway in PM4-stimulated MH-S cells. KRGE suppressed inflammatory cell infiltration and number of immune cells, histopathologic damage, and inflammatory symptoms in the BALF and lungs induced by PM4+D; these included increased alveolar wall thickness, accumulation of collagen fibers, and TNF-α, MIP2, CXCL-1, IL-1α, and IL-17 cytokine release. Moreover, PM4 participates induce alveolar macrophage death and interleukin-1α release by associating with IRAK-1 localization was also potently inhibited by KRGE in the lungs of PM4+D-induced airway inflammation model. KRGE suppresses airway inflammatory responses, including granulocyte infiltration into the airway, by regulating the expression of chemokines and inflammatory cytokines via inhibition of IRAK-1 and MAPK pathway. Conclusion: Our results indicate the potential of KRGE to serve as an effective therapeutic agent against airway inflammation and respiratory diseases.