• 제목/요약/키워드: Polarization Response

검색결과 140건 처리시간 0.033초

The Role of Thymic Stromal Lymphopoietin (TSLP) in Glomerulonephritis

  • Lee, Keum Hwa;Yang, Jae Won;Cho, Jin Young;Lee, Joo Yup;Lim, Eun Kyung;Eisenhut, Michael;Jeong, Dong Yeon;Steingroever, Johanna;Shin, Jae Il
    • Childhood Kidney Diseases
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    • 제22권1호
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    • pp.17-21
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    • 2018
  • Thymic stromal lymphopoietin (TSLP) is an interleukin-7-like cytokine that is an important trigger and initiator of many allergic diseases. TSLP promotes a T-helper type 2 (Th2) cytokine response that can be pathological. A relationship is formed both at the induction phase of the Th2 response through polarization of dendritic cells to drive Th2 cell differentiation and at the effector phase of the response, by promoting the expansion of activated T cells and their secretion of Th2 cytokines and TSLP. In transgenic mice with TSLP overexpression, it has been reported that TSLP leads to the development of mixed cryoglobulinemic membranoproliferative glomerulonephritis. In addition, TSLP can play an important role in the pathogenesis of IgA nephropathy and systemic lupus erythematosus-related nephritis. From our knowledge of the role of TSLP in the kidney, further studies including the discovery of new therapies need to be considered based on the relationship between TSLP and glomerulonephritis.

에폭시의 분극 및 전하 이동 (Polarization and Charge Transport in Epoxy)

  • 안종현;최충석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 추계학술대회 논문집 전기설비전문위원
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    • pp.229-230
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    • 2008
  • The investigations included the measurements of volume currents and also internal space charges on epoxy samples of mm thicknesses. The current versus time relations were shown to correspond well with classical forms of dielectric response such as the Curie-von Schweidler model. After the time transient, near steady currents were extremely small and exhibited a significant temperature dependence, similar in relation to the Poole-Frenkel hoping transport model. Equivalent resistances were on the order of $10^{19}$ ohms and represent very weak charge transport. Electrically stimulated acoustic waves were used to quantify the small internal charges that would accumulate within the epoxy. There was a notable homocharge near both anode and cathode. The dielectric response and the internal charge were related to show a consistent model for charge transport within unfilled epoxy.

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비충전 에폭시의 분극 및 전하 이동 (Polarization and Charge Transport in Unfilled Epoxy)

  • 곽현우;최용성;이경섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.2311-2312
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    • 2008
  • The investigations included the measurements of volume currents and also internal space charges on epoxy samples of mm thicknesses. The current versus time relations were shown to correspond well with classical forms of dielectric response such as the Curie-von Schweidler model. After the time transient, near steady currents were extremely small and exhibited a significant temperature dependence, similar in relation to the Poole-Frenkel hoping transport model. Equivalent resistances were on the order of 1019 ohms and represent very weak charge transport. Electrically stimulated acoustic waves were used to quantify the small internal charges that would accumulate within the epoxy. There was a notable homocharge near both anode and cathode. The dielectric response and the internal charge were related to show a consistent model for charge transport within unfilled epoxy.

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FABRICATION AND CHARACTERIZATION OF NONLINEAR OPTICAL GLASSES

  • Cardinal, T.;Fargin, E.;Le Flem, G.
    • 한국광학회:학술대회논문집
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    • 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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    • pp.4-5
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    • 2001
  • Advent of lasers offering high intensity beam has opened the glass to the nonlinear optic (NLO). The high electric field associated with such laser beams can be so large that high order components of the glass polarization can be measured. Such development is of scientific and technological interests in particular in systems involving an intensity-dependent refractive index and/or ultra-fast response (<10$\^$-12/s). From a scientific viewpoint the NLO response intensity must be understood as a function of the glass composition. On the other hand, large family of applications are presently under investigation in various fields of optical materials or systems e.g. laser glasses for fusion energy, soliton propagation for ultra-long distances, ultra-fast-switching, optical storage etc....(omitted)

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가곡광산 연-아연 광체의 광대역유도분극 반응 특성 (Spectral Induced Polarization Response Charaterization of Pb-Zn Ore Bodies at the Gagok mine)

  • 신승욱;박삼규;신동복
    • 지구물리와물리탐사
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    • 제17권4호
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    • pp.247-252
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    • 2014
  • 가곡광산은 스카른형 광상으로서 섬아연석, 방연석, 황동석, 자류철석 등의 황화광물을 수반한다. 이러한 광물은 전극분극에 의한 IP effect가 크기 때문에 광대역유도분극(spectral induced polarization; SIP)법을 이용하여 효과적으로 탐사할 수 있다. 따라서 이 연구는 황화광물 함량 및 입자의 크기를 지시하는 충전도와 시간상수를 실내 SIP 측정을 통하여 구하고 이로부터 가곡광산 내 두 광체에 대한 광화작용 차이를 비교하는데 목적을 두었다. 이를 위해 남쪽의 월곡광체와 북쪽의 선곡광체를 대상으로 시료를 채취하였다. 시료의 광화작용 특성을 파악하기 위해 휴대용 XRF 측정기를 이용하여 금속의 함량을 측정했고, 실내 암석 SIP 측정시스템을 이용하여 SIP 자료를 획득했다. XRF 측정결과 가곡광산 광체는 철, 아연, 납, 구리 등의 금속을 수반하고 있다. 특히 아연과 철의 함량이 다른 금속과 비교하여 매우 높았고, 이 두 금속은 현미경 관찰을 통하여 섬아연석과 자류철석에 의한 영향으로 판단하였다. SIP 등가회로 분석 결과, 월곡광체가 선곡광체에 비하여 금속의 함량이 더 높았기 때문에 황화광물을 더 많이 수반하는 것으로 판단했고, 이는 SIP에서 충전도의 결과와 잘 부합한다. 반면 선곡광체의 시간상수가 더 컸기 때문에 선곡광체가 월곡광체보다 황화광물 입자 크기가 더 큰 것으로 판단했다.

Computational and experimental characterization of estrogenic activities of 20(S, R)-protopanaxadiol and 20(S, R)-protopanaxatriol

  • Zhang, Tiehua;Zhong, Shuning;Hou, Ligang;Wang, Yongjun;Xing, XiaoJia;Guan, Tianzhu;Zhang, Jie;Li, Tiezhu
    • Journal of Ginseng Research
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    • 제44권5호
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    • pp.690-696
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    • 2020
  • Background: As the main metabolites of ginsenosides, 20(S, R)-protopanaxadiol [PPD(S, R)] and 20(S, R)-protopanaxatriol [PPT(S, R)] are the structural basis response to a series of pharmacological effects of their parent components. Although the estrogenicity of several ginsenosides has been confirmed, however, the underlying mechanisms of their estrogenic effects are still largely unclear. In this work, PPD(S, R) and PPT(S, R) were assessed for their ability to bind and activate human estrogen receptor α (hERα) by a combination of in vitro and in silico analysis. Methods: The recombinant hERα ligand-binding domain (hERα-LBD) was expressed in E. coli strain. The direct binding interactions of ginsenosides with hERα-LBD and their ERα agonistic potency were investigated by fluorescence polarization and reporter gene assays, respectively. Then, molecular dynamics simulations were carried out to simulate the binding modes between ginsenosides and hERα-LBD to reveal the structural basis for their agonist activities toward receptor. Results: Fluorescence polarization assay revealed that PPD(S, R) and PPT(S, R) could bind to hERα-LBD with moderate affinities. In the dual luciferase reporter assay using transiently transfected MCF-7 cells, PPD(S, R) and PPT(S, R) acted as agonists of hERα. Molecular docking results showed that these ginsenosides adopted an agonist conformation in the flexible hydrophobic ligand-binding pocket. The stereostructure of C-20 hydroxyl group and the presence of C-6 hydroxyl group exerted significant influence on the hydrogen bond network and steric hindrance, respectively. Conclusion: This work may provide insight into the chemical and pharmacological screening of novel therapeutic agents from ginsenosides.

Monitoring mRNA Expression Patterns in Macrophages in Response to Two Different Strains of Probiotics

  • Sang-Pil Choi;Si-Won Park;Seok-Jin Kang;Seul Ki Lim;Min-Sung Kwon;Hak-Jong Choi; Taehoon Chun
    • 한국축산식품학회지
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    • 제43권4호
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    • pp.703-711
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    • 2023
  • As an initial study to elucidate the molecular mechanism of how probiotics modulate macrophage activity, we monitored mRNA expression patterns in peritoneal macrophages (PMs) treated with two different strains of probiotics. After treatment with either Weissella cibaria WIKIM28 or Latilactobacillus sakei WIKIM50, total RNAs from PMs were isolated and subjected into gene chip analyses. As controls, mRNAs from vehicle (phosphate-buffered saline, PBS)-treated PMs were also subjected to gene chip analysis. Compared to vehicle (PBS)-treated PMs, WIKIM28-treated and WIKIM50-treated PMs exhibited a total of 889 and 432 differentially expressed genes with expression differences of at least 4 folds, respectively. Compared to WIKIM28-treated PMs, WIKIM50-treated PMs showed 25 up-regulated genes and 21 down-regulated genes with expression differences of more than 2 folds. Interestingly, mRNA transcripts of M2 macrophage polarization marker such as anxa1, mafb, and sepp1 were increased in WIKIM50-treated PMs comparing to those in WIKIM28-treated PMs. Reversely, mRNA transcripts of M1 macrophage polarization marker such as hdac9, ptgs2, and socs3 were decreased in WIKIM50-treated PMs comparing to those in WIKIM28-treated PMs. In agreement with these observations, mRNA expression levels of tumor necrosis factor-α and interleukin-1α were significantly reduced in WIKIM50-treated macrophages compared to those in WIKIM28-treated macrophages. These results may indicate that probiotics can be classified as two different types depending on their ability to convert macrophages into M1 or M2 polarization.

인공지능 노출 정도에 따른 고용 추세 분석: K자형 고용 양극화 (Analyzing employment trends in response to AI exposure: K-shaped labor polarization in Korea)

  • 이예슬;황현준
    • 정보화정책
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    • 제30권3호
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    • pp.69-91
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    • 2023
  • 기술 발전이 고용에 미치는 영향은 자동화에 의한 대체 또는 새로운 업무 도입에 따른 고용 증가 등 여전한 논쟁의 대상이다. 특히 인공지능 기술 발전과 고용에 대한 실증 논의는 더욱 부족한 실정이다. 이에 본 연구는 자연어처리 기법(SBERT)과 특허를 이용하여 직업별 인공지능 노출 점수를 계산하고 평균 점수를 기준으로 상위 집단과 하위 집단으로 구분하여 집단별 고용 추세를 분석한다. 자연어처리 기법을 통해 한국 특허와 미국 직업의 업무 설명을 연계하는 인공지능 노출 점수 계산 방식과 한미 표준직업분류 연계 방식을 제시하고 이를 국내 고용 통계에 적용하여 추세를 분석한다. 2013년 이후 국내 인공지능 출원 특허와 통계청 지역별고용조사를 분석한 결과 한국의 고용은 시간이 지남에 따라 평균 이상의 인공지능 노출 집단에서 우상향하고, 평균 이하 집단에서는 우하향하는 K자형 양극화 양상을 보인다.

Electrochemical Study of Three Stainless Steel Alloys and Titanium Metal in Cola Soft Drinks

  • Peralta-Lopez, D.;Sotelo-Mazon, O.;Henao, J.;Porcayo-Calderon, J.;Valdez, S.;Salinas-Solano, G.;Martinez-Gomez, L.
    • Journal of Electrochemical Science and Technology
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    • 제8권4호
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    • pp.294-306
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    • 2017
  • Stainless steels and titanium alloys are widely used in the medical industry as replacement materials. These materials may be affected by the conditions and type of environment. In the same manner, soft drinks are widely consumed products. It is of interest for dental industry to know the behavior of medical-grade alloys when these are in contact with soft drinks, since any excessive ion release can suppose a risk for human health. In the present study, the electrochemical behavior of three stainless steel alloys and pure titanium was analyzed using three types of cola soft drinks as electrolyte. The objective of this study was to evaluate the response of these metallic materials in each type of solution (cola standard, light and zero). Different electrochemical techniques were used for the evaluation of the alloys, namely potentiodynamic polarization, linear polarization, and open-circuit potential measurements. The corrosion resistance of the stainless-steel alloys and titanium in the cola soft drinks was provided by the formation of a stable passive film formed by metal oxides. Scanning electron microscopy was used as a complementary technique to reveal corrosion phenomena at the surface of the materials evaluated.

고속 데이터베이스 시스템을 위한 컬럼-인지 양분화 기법 (Column-aware Polarization Scheme for High-Speed Database Systems)

  • 변시우
    • 인터넷정보학회논문지
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    • 제13권3호
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    • pp.83-91
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    • 2012
  • 최근 컬럼-기반 저장 장치는 우수한 입출력 성능으로 고속 데이터베이스 시스템의 진보적인 중요 모델이 되었다. 본 논문에서는, 기존의 가로-기반 저장 모델과 비교 분석하고, 고속 컬럼-기반 데이터베이스 시스템의 유효 성능을 향상시키기 위하여, 플래시 메모리와 어시스트 드라이브를 활용한 새로운 컬럼-인지 스토리지 관리 모델을 제안한다. 컬럼-인지 폴라라이징이라고 하는 본 스토리지 관리 기법은 테이블 컬럼을 활성-컬럼과 비활성-컬럼으로 양분하여 압축 저장하며, 고부하시에 어시스트 드라이브를 활용하여 적체된 저장 연산을 리벨런싱한다. 실험 결과는 본 제안 기법이 컬럼-기반 스토리지의 초당 저장 연산 처리치를 19% 개선하였고, 그 응답 성능도 49%개선되었음을 보였다.