• 생명과학회지
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• 제31권9호
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• pp.806-817
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• 2021

우울증 발생 기전에 신경가소성의 손상이 관여한다. Sirtuin 1은 신경가소성의 조절에 중요한 역할을 담당하고 있다. 또한 mTORC1 신호전달의 활성화가 신경가소성을 향상시키는 것으로 알려져 있다. 본 연구는 sirtuin 1이 mTORC1 신호전달을 통해 수상돌기 성장과 가시형성에 미치는지 영향을 조사하였다. 덱사메타손이 처치된 신경세포와 정상 배양 신경세포에 resveratrol (sirtuin 1 활성제)과 sirtinol (sirtuin 1 억제제)을 각각 처치하였다. Western blot 분석법을 사용하여, sirtuin 1 발현 및 ERK1/2, mTORC1, p70S6K의 인산화 양을 분석하였고, 면역형광측정법으로 수상돌기의 길이와 가시밀도를 분석하였다. Resveratrol은 덱사메타손 환경에서 농도 의존적으로 sirtuin 1의 발현을 증가시켰으며, ERK1/2 (sirtuin 1의 하위 타겟), mTORC1, 그리고 p70S6K (mTORC1의 하위 타겟)의 인산화를 유의하게 증가시켰다. 또한 resveratrol은 수상돌기 성장과 가시밀도를 증가시켰다. 반면, sirtinol은 정상 배양액에서 sirtuin 1의 발현을 유의하게 감소시켰으며, ERK1/2, mTORC1, p70S6K의 인산화 양을 농도 의존적으로 유의하게 감소시켰다. 또한 sitinol은 수상돌기 성장과 가시밀도를 유의하게 감소시켰다. 신경세포에 sirtuin 1의 siRNA를 transfection시켜 sirtuin 1을 knockdown 시켰을 때, ERK1/2 및 mTORC1의 인산화 양이 감소하였을 뿐만 아니라, 수상돌기 성장과 가시밀도도 감소하였다. 본 연구는 sirtuin 1이 ERK1/2-mTORC1 신호전달을 통해서 수상돌기 성장과 가시밀도를 변화시켜 신경가소성을 조절한다는 것을 보여주었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.89.1-89.1
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• 2010

Since Gratzel and co-workers developed a new type of solar cell based on the nanocrystalline $TiO_2$ electrode, dye-sensitized solar cells (DSSCs) have attracted considerable attention on account of their high solar energy-to-conversion efficiencies (11%), their easy manufacturing process with low cost production compared to conventional p-n junction solar cells. The mechanism of DSSC is based on the injection of electrons from the photoexcited dye into the conduction band of nanocrystalline $TiO_2$. The oxidized dye is reduced by the hole injection process from either the hole counter or electrolyte. Thus, the electronic structures, such as HOMO, LUMO, and HOMO-LUMO gap, of dye molecule in DSSC are deeply related to the electron transfer by photoexcitation and redox potential. To date, high performance and good stability of DSSC based on Ru-dyes as a photosensitizer had been widely addressed in the literatures. DSSC with Ru-bipyridyl complexes (N3 and N719), and the black ruthenium dye have achieved power conversion efficiencies up to 11.2% and 10.4%, respectively. However, the Ru-dyes are facing the problem of manufacturing costs and environmental issues. In order to obtain even cheaper photosensitizers for DSSC, metal-free organic photosensitizers are strongly desired. Metal-free organic dyes offer superior molar extinction coefficients, low cost, and a diversity of molecular structures, compared to conventional Ru-dyes. Recently, novel photosensitizers such as coumarin, merocyanine, cyanine, indoline, hemicyanine, triphenylamine, dialkylaniline, bis(dimethylfluorenyl)-aminophenyl, phenothiazine, tetrahydroquinoline, and carbazole based dyes have achieved solar-to-electrical power conversion efficiencies up to 5-9%. On the other hand, organic dye molecules have large ${\pi}$-conjugated planner structures which would bring out strong molecular stacking in their solid-state and poor solubility in their media. It was well known that the molecular stacking of organic dyes could reduce the electron transfer pathway in opto-electronic devices, significantly. In this paper, we have studied on synthesis and characterization of dendritic organic dyes with different number of electron acceptor/anchoring moieties in the end of dendrimer. The photovoltaic performances and the incident photon-to-current (IPCE) of these dyes were measured to evaluate the effects of the dendritic strucuture on the open-circuit voltage and the short-circuit current.

• 한국식품영양과학회지
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• 제44권2호
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• pp.182-190
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• 2015

본 연구는 홍삼추출물(홍삼단)과 생약복합추출물(헤모힘)이 주요 기능성분은 다르지만 면역활성이라는 생리활성 측면에서 동일한 효과를 인정하고 있어서 이들의 병용 처리가 면역세포에 어떠한 영향을 미치는지에 대해 알아보기 위하여 수행되었다. 면역활성능에 관한 평가를 진행하기 위하여 마우스의 골수에서 분리한 미분화 골수세포를 선천면역에서 중요한 역할을 수행하는 대식세포 및 수지상세포로 분화시킨 후 홍삼추출물과 생약복합추출물을 병용 처리하였을 때 대식세포 및 수지상세포의 세포 증식능 및 사이토카인의 분비능이 증가되는 것으로 관찰되었다. 또한 활성화된 탐식(면역)세포의 세포 표면에서 발현되는 CD80과 CD86의 발현과 탐식(면역)세포의 항원제시에 밀접한 관련이 있는 주 조직적합성 복합체(MHC class II)의 발현이 홍삼추출물과 생약복합추출물의 병용 처리구에서 유의적으로 증가되는 것으로 관찰되었다. 또한 후천면역에서 중요한 역할을 수행하는 면역 T 세포가 다량으로 분포하는 비장 조직으로부터 비장세포를 분리하여 홍삼추출물과 생약복합추출물을 병용처리하였을 때 세포 증식능 및 면역활성을 유도하는 Th1 세포가 분비하는 사이토카인의 함량이 증가되는 것으로 나타났다. 이러한 결과로 미루어 볼 때 홍삼추출물과 생약복합 추출물의 병용 처리는 선천면역뿐만 아니라 후천면역에 관여하는 다양한 면역세포의 활성화에 직 간접적으로 다양한 상승작용을 미치는 것으로 사료된다.

• Parasites, Hosts and Diseases
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• 제58권3호
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• pp.237-247
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• 2020

Dendritic cell is one of the first innate immune cell to encounter T. gondii after the parasite crosses the host intestinal epithelium. T. gondii requires intact DC as a carrier to infiltrate into host central nervous system (CNS) without being detected or eliminated by host defense system. The mechanism by which T. gondii avoids innate immune defense of host cell, especially in the dendritic cell is unknown. Therefore, we examined the role of host PI3K/AKT signaling pathway activation by T. gondii in dendritic cell. T. gondii infection or T. gondii excretory/secretory antigen (TgESA) treatment to the murine dendritic cell line DC2.4 induced AKT phosphorylation, and treatment of PI3K inhibitors effectively suppressed the T. gondii proliferation but had no effect on infection rate or invasion rate. Furthermore, it is found that T. gondii or TgESA can reduce H₂O₂-induced intracellular reactive oxygen species (ROS) as well as host endogenous ROS via PI3K/AKT pathway activation. While searching for the main source of the ROS, we found that NADPH oxidase 4 (NOX4) expression was controlled by T. gondii infection or TgESA treatment, which is in correlation with previous observation of the ROS reduction by identical treatments. These findings suggest that the manipulation of the host PI3K/AKT signaling pathway and NOX4 expression is an essential mechanism for the down-regulation of ROS, and therefore, for the survival and the proliferation of T. gondii.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.117.2-117.2
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• 2011

Since Gratzel and co-workers developed a new type of solar cell based on the nanocrystalline TiO2 electrode, dye-sensitized solar cells (DSSCs) have attracted considerable attention on account of their high solar energy-to-conversion efficiencies (11%), their easy manufacturing process with low cost production compared to conventional p-n junction solar cells. The mechanism of DSSC is based on the injection of electrons from the photoexcited dye into the conduction band of nanocrystalline TiO2. The oxidized dye is reduced by the hole injection process from either the hole counter or electrolyte. Thus, the electronic structures, such as HOMO, LUMO, and HOMO-LUMO gap, of dye molecule in DSSC are deeply related to the electron transfer by photoexcitation and redox potential. To date, high performance and good stability of DSSC based on Ru-dyes as a photosensitizer had been widely addressed in the literatures. DSSC with Ru-bipyridyl complexes (N3 and N719), and the black ruthenium dye have achieved power conversion efficiencies up to 11.2% and 10.4%, respectively. However, the Ru-dyes are facing the problem of manufacturing costs and environmental issues. In order to obtain even cheaper photosensitizers for DSSC, metal-free organic photosensitizers are strongly desired. Metal-free organic dyes offer superior molar extinction coefficients, low cost, and a diversity of molecular structures, compared to conventional Ru-dyes. Recently, novel photosensitizers such as coumarin, merocyanine, cyanine, indoline, hemicyanine, triphenylamine, dialkylaniline, bis(dimethylfluorenyl)-aminophenyl, phenothiazine, tetrahydroquinoline, and carbazole based dyes have achieved solar-to-electrical power conversion efficiencies up to 5-9%. On the other hand, organic dye molecules have large ${\pi}$-conjugated planner structures which would bring out strong molecular stacking in their solid-state and poor solubility in their media. It was well known that the molecular stacking of organic dyes could reduce the electron transfer pathway in opto-electronic devices, significantly. In this paper, we have studied on synthesis and characterization of dendritic organic dyes with different number of electron acceptor/anchoring moieties in the end of dendrimer. The photovoltaic performances and the incident photon-to-current (IPCE) of these dyes were measured to evaluate the effects of the dendritic strucuture on the open-circuit voltage and the short-circuit current.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2419-2423
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• 2015

Background: There are few choices for treatment of advanced cancer patients who do not respond to or tolerate conventional anti-cancer treatments. Therefore this study aimed to deploy the benefits and clinical efficacy of continuous dendritic cell-cytokine induced killer cell infusions in such patients. Materials and Methods: A total of 381 infusions (from 67 advanced cases recruited) were included in this study. All patients underwent peripheral blood mononuclear cell apheresis for the following cellular therapy and dendritic cells-cytokine induced killer cells were expanded in vitro. Peripheral blood T lymphocyte subsets were quantified through flow cytometry to address the cellular immunity status. Clinical efficacy and physical activities were evaluated by RECIST criteria and Eastern Cooperative Oncology Group scores respectively. Logistic regression model was used to estimate the association between cellular infusions and clinical benefits. Results: An average of $5.7{\pm}2.94{\times}10^9$ induced cells were infused each time and patients were exposed to 6 infusions. Cellular immunity was improved in that cytotoxic $CD8^+CD28^+$ T lymphocytes were increased by 74% and suppressive $CD8^+CD28^-$ T lymphocytes were elevated by 16% (p<0.05). Continuous infusion of dendritic cells-cytokine induced killer cells was associated with improvement of both patient status and cellular immunity. A median of six infusions were capable of reducing risk of progression by 70% (95%CI 0.10-0.91). Every elevation of one ECOG score corresponded to a 3.90-fold higher progression risk (p<0.05) and 1% increase of $CD8^+CD28^-$ T cell proportion reflecting a 5% higher risk of progression (p<0.05). Conclusions: In advanced cancer patients, continuous dendritic cell-cytokine induced killer cell infusions are capable of recovering cellular immunity, improving patient status and quality of life in those who are unresponsive to conventional cancer treatment.

• 생명과학회지
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• 제25권12호
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• pp.1425-1431
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• 2015

면역 시스템의 림프구는 B 림프구와 T 림프구 두 종류로 나눌 수 있다. B 림프구는 플라즈마 세포로 분화하여 항체를 생성하는 체액성 면역을 담당하며, T 림프구는 다른 세포나 세균을 죽이는 세포성 면역을 담당한다. 고전적으로 B 림프구와 T 림프구의 작용은 한 방향으로 이뤄졌다. T 림프구는 B 림프구의 분화를 촉진하고 면역글로불린종류의 전환을 조절한다. T 림프구가 부족한 경우 B 림프구의 부족을 초래함이 보고되어 있다. 그러나 최근에 역으로 B 림프구가 T 림프구의 분화와 활성을 조절할 수 있다는 보고가 있다. 예를 들어, B 림프구는 CD8+ T 림프구의 tolerance를 직접 조절할 수 있고, TGF-β의 분비를 통해 T 림프구의 anergy를 유도할 수 있다. 본 연구는 LPS에 의해 자극된 B 림프구가 수지상세포에서 IL-12의 분비를 억제하여 Th1 림프구의 분화를 억제할 수 있음을 보여준다. 이 억제는 B 림프구와 수지상세포의 직접적인 interaction에 의해 일어나는 것이 아니며 B 림프구가 수지상세포의 성숙을 조절하여 일어나는 것도 아니다. B 림프구에서 분비되는 soluble factor가 LPS에 의해 증가되는 수지상세포의 IL-12p35 transcription을 억제한다. 이 결과들은 B 림프구가 매개하는 새로운 면역억제 기전이 존재함을 보여준다. 이것은 고전적인 방향성을 가진 T 림프구에 의한 B 림프구 작용조절로 면역반응이 결정되는 것이 아니라 T 림프구와 B 림프구가 서로 작용을 하여 면역평형을 결정하는 기전이 존재함을 보여준다.

• 한국수소및신에너지학회논문집
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• 제23권4호
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• pp.390-396
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• 2012

In order to understand the nature of dendritic zinc growth, electrochemical zinc redox reaction on nickel plate was investigated in aqueous solutions containing different concentrations, 0.2, 0.1 and 0.02 $mol{\cdot}dm^{-3}$ (M), of zinc sulfate ($ZnSO_4$) or zinc chloride ($ZnCl_2$). Zinc ion was efficiently reduced and oxidized on nickel in the high-concentration (0.2 M) solution, whereas relatively poor efficiency was obtained from the other low-concentration solutions (0,1 and 0.02 M). Cyclic voltammetry (CV) analysis revealed that the 0.2 M electrolyte solution decomposes at more positive potentials than the 0.1 and the 0.02 M solutions. These results suggested that the concentration of electrolyte solution and anion would be an important factor that suppresses the reaction of the zinc dendrite formation. Scanning Electron Microscopy (SEM) data revealed that the shape of dendritic zinc and its growing behavior were also influenced by electrolyte concentration.

• 폴리머
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• 제33권2호
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• pp.158-163
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• 2009

본 연구에서는 잘 정의된 덴드리틱 폴리스티렌-블록-선형 폴리(3차 부틸 아크릴레이트) 공중합체를 성공적으로 합성하였다. 음이온 중합법을 통해 합성된 폴리스티렌($M_n$=1000 g/mol)을 외곽부분으로 함유하는 덴드론의 수산기 그룹을 토실화(tosylation), 아지드화(azidation), 환원(reduction) 반응을 통해 아민기로 전환하였다. 한편, 선형 poly(t-butyl acrylate)는 DMF 용매에서 benzyl 2-bromopropanoate/Cu(I)Br, PMDETA/t-butylacrylate를 각각 개시제/촉매 시스템/단량체로 사용하여, 원자이동라디칼 중합법(atom transfer radical polymerization, ATRP)을 통해 합성할 수 있었고, 말단을 카르복시산 그룹으로 전환하기 위해 수소기체 환경하에서 Pd/C 을 사용하여 탈벤질화(debenzylation) 반응을 수행하였다. 마지막으로, 합성된 덴드리틱 및 선형 블록들을 다이메틸아미노피리딘(4-(dimethylamino)pyridine, DMAP)과 다이아이소프로필카보다이이미드(N,N'-diisopropylcarbodiimide, DIPC)를 이용한 아미드 커플링 방법을 통해 최종 덴드리틱-선형의 블록공중합체를 합성하였다. 합성된 블록공중합체를 수소원자핵공명법 및 겔침투크로마토그래피 방법을 통해 조사한 결과, 잘 정의된 분자량 및 낮은 분자량 분포를 확인할 수 있었다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2004년도 Annual Meeting BioExibition International Symposium
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• pp.151-151
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• 2004