• 제목/요약/키워드: Bio-hydrogen

검색결과 319건 처리시간 0.02초

높은 안정성을 갖는 초미립 폴리에틸렌이민-금 나노입자 (Ultrasmall Polyethyleneimine-Gold Nanoparticles with High Stability)

  • 김은정;염정현;김한도;이세근;이가현;이현주;한상익;최진현
    • 폴리머
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    • 제35권2호
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    • pp.161-165
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    • 2011
  • 본 연구는 수계에서 오랜 시간 동안 안정한 생체적합 금 나노업자의 제조에 관한 것으로, 환원제와 안정제의 역할을 동시에 수행하는 폴리에틸렌이민을 이용해 응집성이 낮은 초미립 폴리에틸렌이민 금 나노입자를 상온의 수용액 상에서 합성하였다. 폴리에틸렌이민 금 나노입자의 평균 입자크기는 8~12 nm이었고, 수계의 나노콜로이드 %에서 50nm 내외의 클러스터를 형성하였으며, 매우 뛰어난 안정성을 보였다. 상대적으로 낮은 금속 전구체의 농도에서 나노입자를 제조하였을 때, 입자의 크기가 두드러지게 감소하는 경향을 나타내었다. 폴리에틸렌이민-금 나노입자의 X-선 회절분석 결과, 금에서 나타나는 전형적인 결정 피크가 발견되었다. 또한 세포배양실험 결과, 폴리에틸렌이민과는 달리 폴리에틸렌이민-금 나노입자는 98%의 세포 생존율을 보여 세포독성은 거의 없는 것으로 나타났다. 이상의 결과로부터 본 연구에서 합성된 폴리에틸렌이민-금 나노입자는 CT 조영제 등으로의 활용이 기대된다.

Pharmacophore Identification for Peroxisome Proliferator-Activated Receptor Gamma Agonists

  • Sohn, Young-Sik;Lee, Yu-No;Park, Chan-In;Hwang, S-Wan;Kim, Song-Mi;Baek, A-Young;Son, Min-Ky;Suh, Jung-Keun;Kim, Hyong-Ha;Lee, Keun-Woo
    • Bulletin of the Korean Chemical Society
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    • 제32권1호
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    • pp.201-207
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    • 2011
  • Peroxisome proliferator-activated receptors (PPARs) are members of nuclear receptors and their activation induces regulation of fatty acid storage and glucose metabolism. Therefore, the $PPAR\gamma$ is a major target for the treatment of type 2 diabetes mellitus. In order to generate pharmacophore model, 1080 known agonists database was constructed and a training set was selected. The Hypo7, selected from 10 hypotheses, contains four features: three hydrogen-bond acceptors (HBA) and one general hydrophobic (HY). This pharmacophore model was validated by using 862 test set compounds with a correlation coefficient of 0.903 between actual and estimated activity. Secondly, CatScramble method was used to verify the model. Hence, the validated Hypo7 was utilized for searching new lead compounds over 238,819 and 54,620 chemical structures in NCI and Maybridge database, respectively. Then the leads were selected by screening based on the pharmacophore model, predictive activity, and Lipinski's rules. Candidates were obtained and subsequently the binding affinities to $PPAR\gamma$ were investigated by the molecular docking simulations. Finally the best two compounds were presented and would be useful to treat type 2 diabetes.

Pharmacophore Mapping and Virtual Screening for SIRT1 Activators

  • Sakkiah, Sugunadevi;Krishnamoorthy, Navaneethakrishnan;Gajendrarao, Poornima;Thangapandian, Sundarapandian;Lee, Yun-O;Kim, Song-Mi;Suh, Jung-Keun;Kim, Hyong-Ha;Lee, Keun-Woo
    • Bulletin of the Korean Chemical Society
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    • 제30권5호
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    • pp.1152-1156
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    • 2009
  • Silent information regulator 2 (Sir2) or sirtuins are NAD(+)-dependent deacetylases, which hydrolyze the acetyllysine residues. In mammals, sirtuins are classified into seven different classes (SIRT1-7). SIRT1 was reported to be involved in age related disorders like obesity, metabolic syndrome, type II diabetes mellitus and Parkinson’s disease. Activation of SIRT1 is one of the promising approaches to treat these age related diseases. In this study, we have used HipHop module of CATALYST to identify a series of pharmacophore models to screen SIRT1 enhancing molecules. Three molecules from Sirtris Pharmaceuticals were selected as training set and 607 sirtuin activator molecules were used as test set. Five different hypotheses were developed and then validated using the training set and the test set. The results showed that the best pharmacophore model has four features, ring aromatic, positive ionization and two hydrogen-bond acceptors. The best hypothesis from our study, Hypo2, screened high number of active molecules from the test set. Thus, we suggest that this four feature pharmacophore model could be helpful to screen novel SIRT1 activator molecules. Hypo2-virtual screening against Maybridge database reveals seven molecules, which contains all the critical features. Moreover, two new scaffolds were identified from this study. These scaffolds may be a potent lead for the SIRT1 activation.

Bacillus sp. SP-KSW3를 이용하여 제조한 된장 발효 과정중의 효소 활성 및 기능성의 변화 (Changes of Enzyme Activity and Physiological Functionality of Traditional Doenjang during Fermentation Using Bacillus sp. SP-KSW3)

  • 김병수;이창호;홍영아;우철주;장철민;김영배;박희동
    • 한국식품저장유통학회지
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    • 제14권5호
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    • pp.545-551
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    • 2007
  • 청국장 제조시 사용되는 균주인 Bacillus sp. SP-KSW3을 메주 제조시 starter로 접종하여 발효시킨 메주를 이용하여 된장을 담근 후 일정기간 숙성시킨 다음 된장의 이화학적 성질 등의 변화를 측정하였다. NaCl의 함량은 숙성 숙성기간이 길어질수록 증가하였으며, 아미노산도는 대조구보다 실험구가 높게 나타났다. Amylase와 protease의 활성은 모두 대조구와 실험구가 비슷한 경향을 나타내었으며, Tyrosinase의 저해 활성과 ACE 저해 활성은 숙성기간이 동일한 경우 대조구 보다 실험구가 약 10% 이상 높은 활성을 나타내었다. 항돌연변이 활성은 2년간 숙성시킨 경우에 실험구가 대조구 보다 높은 활성을 나타내었으며, S. enterica serovar Typhimurium TA100을 사용한 경우 변이원 MNNG와 NPD에 대한 항돌연변이 활성은 각각 86.24%와 75.63%를 나타내었다. 또한, S. enterica serovar Typhimurium TA98을 사용한 경우 변이원 NPD와 NQO에 대한 항돌연변이 활성은 각각 60.28%와 50.92%를 나타내었다. 수소 공여능은 숙성기간에 관계없이 대조구보다 실험구가 각각 80.0%와 81.7%로 높게 나타났다. 된장의 isoflavon 중 daidzin은 대조구가 높게 나타났으며 genistin은 실험구를 2년간 숙성시킨 경우 11.67 mg/kg, daidzein은 실험구가 각각 389.96 mg/kg와 453.67 mg/kg, genistein은 각각 402.68 mg/kg와 556.86 mg/kg으로 나타났다.

Antimelanogenesis and skin-protective activities of Panax ginseng calyx ethanol extract

  • Lee, Jeong-Oog;Kim, Eunji;Kim, Ji Hye;Hong, Yo Han;Kim, Han Gyung;Jeong, Deok;Kim, Juewon;Kim, Su Hwan;Park, Chanwoong;Seo, Dae Bang;Son, Young-Jin;Han, Sang Yun;Cho, Jae Youl
    • Journal of Ginseng Research
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    • 제42권3호
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    • pp.389-399
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    • 2018
  • Background: The antioxidant effects of Panax ginseng have been reported in several articles; however, little is known about the antimelanogenesis effect, skin-protective effect, and cellular mechanism of Panax ginseng, especially of P. ginseng calyx. To understand how an ethanol extract of P. ginseng berry calyx (Pg-C-EE) exerts skin-protective effects, we studied its activities in activated melanocytes and reactive oxygen species (ROS)-induced keratinocytes. Methods: To confirm the antimelanogenesis effect of Pg-C-EE, we analyzed melanin synthesis and secretion and messenger RNA and protein expression levels of related genes. Ultraviolet B (UVB) and hydrogen peroxide ($H_2O_2$) were used to induce cell damage by ROS generation. To examine whether this damage is inhibited by Pg-C-EE, we performed cell viability assays and gene expression and transcriptional activation analyses. Results: Pg-C-EE inhibited melanin synthesis and secretion by blocking activator protein 1 regulatory enzymes such as p38, extracellular signal-regulated kinases (ERKs), and cyclic adenosine mono-phosphate response element-binding protein. Pg-C-EE also suppressed ROS generation induced by $H_2O_2$ and UVB. Treatment with Pg-C-EE decreased the expression of matrix metalloproteinases, mitogen-activated protein kinases, and hyaluronidases and increased the cell survival rate. Conclusion: These results suggest that Pg-C-EE may have antimelanogenesis properties and skin-protective properties through regulation of activator protein 1 and cyclic adenosine monophosphate response element-binding protein signaling. Pg-C-EE may be used as a skin-improving agent, with moisture retention and whitening effects.

쥐 흑색종 세포에서 산화적 스트레스에 의한 MMPs의 발현과 활성에 대한 흑도라지 추출물의 억제 효과 (Inhibitory Effect of Aged Black Platycodi Radix Extract on Expression and Activation of Matrix Metalloproteinases in Oxidative-stressed Melanoma Cells)

  • 채용병;이수진;장호정;박정애;김문무;정경태
    • 생명과학회지
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    • 제20권5호
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    • pp.736-744
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    • 2010
  • 도라지는 민간에서 항궤양, 항진통, 항알러지, 혈관과 히스타민 억제 및 항산화 효과가 있는 것으로 알려져 있고, 그 뿌리인 길경은 아시아에서 식용으로 즐겨먹는 식품 소재로 사포닌이 과량 함유되어 있는 것으로 보고 되어 있으나, 그 작용기전은 과학적으로 해명되지 않았다. 본 연구에서 처음으로 흑도라지가 특정한 공정기술을 이용하여 개발되었으며, 산화적 스트레스 및 MMPs) 대한 ABPRE의 억제 효과를 조사하였다. ABPRE의 항산화효과를 조사하기 위해서 DPPH radical, hydroxyl radical, reducing power, hydrogen peroxide, lipid peroxidation 및 DNA 산화에 대한 연구를 수행하였다. 연구 결과 ABPRE는 DPPH radical 소거에는 효과를 나타내었으나 지질과산화에 의한 malondialdehyde의 생성은 억제하지 않았다. 그러나, ABPRE의 존재 하에서 산화적 DNA 손상이 억제되었다. 또한 gelatin zymography 및 western blot 분석에서 ABPRE는 PMS (phenazine methosulfate)에 의해서 자극된 MMP-2의 발현과 활성을 감소시켰으며, ABPRE는 항산화 효과 및 tyrosinase 발현 억제에 의한 L-DOPA로 유발된 melanin 생성을 저해 하였을 뿐만 아니라 Nrf2에 의해서 조절되는 항산화 효소인 SOD-1과 SOD-2의 발현을 증가시키는 것으로 나타났다. 그러므로 ABPRE는 항산화와 관련 있는 암전이의 예방을 위한 항암제의 후보 소재로 그 가능성이 기대된다.

Identification and Characterization of Alternative Promoters of the Rice MAP Kinase Gene OsBWMK1

  • Koo, Sung Cheol;Choi, Man Soo;Chun, Hyun Jin;Park, Hyeong Cheol;Kang, Chang Ho;Shim, Sang In;Chung, Jong Il;Cheong, Yong Hwa;Lee, Sang Yeol;Yun, Dae-Jin;Chung, Woo Sik;Cho, Moo Je;Kim, Min Chul
    • Molecules and Cells
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    • 제27권4호
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    • pp.467-473
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    • 2009
  • Our previous study suggested that OsBWMK1, a gene which encodes a member of the rice MAP kinase family, generates transcript variants which show distinct expression patterns in response to environmental stresses. The transcript variants are generated by alternative splicing and by use of alternative promoters. To test whether the two alternative promoters, pOsBWMK1L (promoter for the OsBWMK1L splice variant) and pOsBWMK1S (promoter for the OsBWMK1S splice variant), are biologically functional, we analyzed transgenic plants expressing GUS fusion constructs for each promoter. Both pOsBWMK1L and pOsBWMK1S are biologically active, although the activity of pOsBWMK1S is lower than that of pOsBWMK1L. Histochemical analysis revealed that pOsBWMK1L is constitutively active in most tissues at various developmental stages in rice and Arabidopsis, whereas pOsBWMK1S activity is spatially and temporally restricted. Furthermore, the expression of pOsBWMK1S::GUS was upregulated in response to hydrogen peroxide, a plant defense signaling molecule, in both plant species. These results suggest that the differential expression of OsBWMK1 splice variants is the result of alternative promoter usage and, moreover, that the mechanisms controlling OsBWMK1 gene expression are conserved in both monocot and dicot plants.

상황버섯 추출액을 이용하여 제조한 된장의 효소 활성 및 기능성의 변화 (Changes in Enzyme Activity and Physiological Functionality of Doenjang (Soybean Paste) Prepared with Extracts of Phellinus linteus)

  • 이창호;김병수;신미경;우철주;김정희;권기영;박희동
    • 한국식품저장유통학회지
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    • 제15권5호
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    • pp.736-742
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    • 2008
  • 전통 된장의 숙성기간 중 기능적 특성의 변화를 조사하기 위하여 상황버섯 추출물을 이용하여 된장을 담금하여 일정기간 숙성한 후, 된장의 protease 활성, 항돌연변이 활성, isoflavone 등을 측정하였다. Protease의 활성은 상황버섯 추출물을 이용한 실험구가 3.15 unit/mL로 대조구보다 높은 활성을 나타내었으며 tyrosinase의 저해 활성과 ACE 저해 활성은 실험구가 각각 45.78%와 55.18%로 대조구보다 약 20% 이상 높은 활성을 나타내었다. 항돌연변이 활성은 실험구가 S. enterica serovar Typhimurium TA100을 사용한 경우 변이원 MNNG와 NPD에 대한 항돌연변이 활성은 각각 90.42%와 82.57%, S. enterica serovar Typhimurium TA98을 사용한 경우 변이원 NPD와 NQO에 대한 항돌연변이 활성은 각각 60.28%와 50.33%로 대조구보다 높은 활성을 나타내었다. 수소 공여능은 실험구의 활성이 86.65%로 대조구의 61.69%보다 높게 나타났다. 상황버섯 추출물을 이용하여 제조한 된장의 isoflavon 중 glucoside인 daidzin은 실험구가 35.49 mg/kg높게 나타났으며 genistin은 실험구와 대조구 모두에서 검출되지 않았다. Aglycone인 daidzein과 genistein은 각각 263.01 mg/kg와 262.60 mg/kg로 대조구 보다 높은 함량을 나타내었다.

Regulation of toll-like receptors expression in muscle cells by exercise-induced stress

  • Park, Jeong-Woong;Kim, Kyung-Hwan;Choi, Joong-Kook;Park, Tae Sub;Song, Ki-Duk;Cho, Byung-Wook
    • Animal Bioscience
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    • 제34권10호
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    • pp.1590-1599
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    • 2021
  • Objective: This study investigates the expression patterns of toll-like receptors (TLRs) and intracellular mediators in horse muscle cells after exercise, and the relationship between TLRS expression in stressed horse muscle cells and immune cell migration toward them. Methods: The expression patterns of the TLRs (TLR2, TLR4, and TLR8) and downstream signaling pathway-related genes (myeloid differentiation primary response 88 [MYD88]; activating transcription factor 3 [ATF3]) are examined in horse tissues, and horse peripheral blood mononuclear cells (PBMCs), polymorphonuclear cells (PMNs) and muscles in response to exercise, using the quantitative reverse transcription-polymerase chain reaction (qPCR). Expressions of chemokine receptor genes, i.e., C-X-C motif chemokine receptor 2 (CXCR2) and C-C motif chemokine receptor 5 (CCR5), are studied in PBMCs and PMNs. A horse muscle cell line is developed by transfecting SV-T antigen into fetal muscle cells, followed by examination of muscle-specific genes. Horse muscle cells are treated with stressors, i.e., cortisol, hydrogen peroxide (H2O2), and heat, to mimic stress conditions in vitro, and the expression of TLR4 and TLR8 are examined in stressed muscle cells, in addition to migration activity of PBMCs toward stressed muscle cells. Results: The qPCR revealed that TLR4 message was expressed in cerebrum, cerebellum, thymus, lung, liver, kidney, and muscle, whereas TLR8 expressed in thymus, lung, and kidney, while TLR2 expressed in thymus, lung, and kidney. Expressions of TLRs, i.e., TLR4 and TLR8, and mediators, i.e., MYD88 and ATF3, were upregulated in muscle, PBMCs and PMNs in response to exercise. Expressions of CXCR2 and CCR5 were also upregulated in PBMCs and PMNs after exercise. In the muscle cell line, TLR4 and TLR8 expressions were upregulated when cells were treated with stressors such as cortisol, H2O2, and heat. Migration of PBMCs toward stressed muscle cells was increased by exercise and oxidative stresses, and combinations of these. Treatment with methylsulfonylmethane (MSM), an antioxidant on stressed muscle cells, reduced migration of PBMCs toward stressed muscle cells. Conclusion: In this study, we have successfully cultured horse skeletal muscle cells, isolated horse PBMCs, and established an in vitro system for studying stress-related gene expressions and function. Expression of TLR4, TLR8, CXCR2, and CCR5 in horse muscle cells was higher in response to stressors such as cortisol, H2O2, and heat, or combinations of these. In addition, migration of PBMCs toward muscle cells was increased when muscle cells were under stress, but inhibition of reactive oxygen species by MSM modulated migratory activity of PBMCs to stressed muscle cells. Further study is necessary to investigate the biological function(s) of the TLR gene family in horse muscle cells.

농업용 전기운반차의 주행성능 향상을 위한 구조해석에 관한 연구 (A Study on Structural Analysis for Improving Driving Performance of Agricultural Electric Car)

  • 조재현;이상식
    • 한국정보전자통신기술학회논문지
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    • 제13권6호
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    • pp.556-561
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    • 2020
  • 현대 사회의 농업 인구의 고령화 및 감소로 농업 환경 개선이 필요한 실정이고 대표적인 문제 중 하나이다. 그리고 대부분의 작업체계에서 항상 운반 작업이 필요하기 때문에 운반 작업에 사용되는 시간과 노동력의 비율이 매우 높다. 이에 따라 많은 종류의 운반차들이 개발되고 판매되고 있으며, 초기에는 대부분 화석연료를 사용하는 동력운반차가 주종을 이루고 있다. 그러나 최근에는 지구온난화와 기후변화협약 등 국제 환경규제의 강화 및 화석연료의 고갈로 인한 수소, 연료전지, 태양광, 바이오 등 차세대 친환경에너지를 주목하고 있다. 그래서 본 연구에서는 화석연료를 대체하는 친환경적이며 누구나 쉽게 조작이 가능하고 안전한 농업용 전기운반차를 개발하는 것을 최종목표로 한다. 농업용 전기운반차의 광범위한 차속 조절 및 안정성 확보에 초점을 두고 설계하였으며, 성능 및 디자인을 고려하여 프레임, 주행부, 조향부, 컨트롤러 시스템 등으로 구성되어 각 부분별 검토하였다. 본 연구의 농업용 전기운반차가 젊은 인력이 부족한 농경사회에서 고령노동자나 여성들이 쉽고 편하게 작업을 할 수 있고 높은 효율성을 통해서 농경사회에 도움이 될 수 있을 것이다.