• 제목/요약/키워드: Natural Degradation

검색결과 786건 처리시간 0.024초

외부탄소원으로 활성화된 토착미생물에 의한 화약물질(TNT and RDX) 분해 최적화 (Optimization of Explosive Compounds (TNT and RDX) Biodegradation by Indigenous Microorganisms Activated by External Carbon Source)

  • 박지은;배범한
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제19권3호
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    • pp.56-65
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    • 2014
  • Contamination of explosive compounds in the soils of military shooting range may pose risks to human and ecosystems. As shooting ranges are located at remote places, active remediation processes with hardwares and equipments are less practical to implement than natural solutions such as bioremediaton. In this study, a series of experiments was conducted to select a suitable carbon source and to optimize dosing rate for the enhanced bioremediation of explosive compounds in surface soils and sediments of shooting ranges with indigenous microorganisms activated by external carbon source. Treatability study using slurry phase reactors showed that the presence of indigenous microbial community capable of explosive compounds degradation in the shooting range soils, and starch was a more effective carbon source than glucose and acetic acid in the removal of TNT. However, at higher starch/soil ratio, i.e., 2.0, the acute toxicity of the liquid phase increased possibly due to transformation products of TNT. RDX degradation by indigenous microorganisms was also stimulated by the addition of starch but the acute toxicity of the liquid phase decreased with the increase of starch/soil ratio. Taken together, the optimum range of starch/soil ratio for the degradation of explosive compounds without significant increase in acute toxicity was found to be 0.2 of starch/soil.

Lycorine의 사람 구강 암 세포주에서 survivin 단백질 분해 증진으로 세포자멸사 유도 (Lycorine induces apoptosis by enhancing protein degradation of survivin in human oral cancer cell lines)

  • 정요셉;조남표;장분실
    • 대한구강악안면병리학회지
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    • 제41권1호
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    • pp.1-7
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    • 2017
  • Lycorine, a natural alkaloid extracted from the Amaryllidaceae plant family, was reported to various physiological and pharmacological effects including anti-cancer activity. Nevertheless, there is no report of the anticancer effect of lycorine in oral cancer cells. The effects of lycorine on cell proliferation and apoptosis were examined through trypan blue exclusion assay, 4'-6-diamidino-2-phenylindole (DAPI) stain, Live/Dead assay, Western blot analysis and RT-PCR. Lycorine suppressed cell viability and induced apoptosis in MC3 and HSC-3 cell lines. Lycorine decreased survivin protein but did not affect its mRNA. It regulated survivin through accelerating protein degradation in a time-dependent manner although neither proteasome nor lysosome was not associated with lycorine-mediated protein degradation. Collectively, our results suggest that lycorine may be a potential therapeutic anti-cancer drug candidate for the treatment of human oral cancer.

Residual behavior of SRRAC beam and column after exposure to high temperatures

  • Zhou, Ji;Chen, Zongping;Zhou, Chunheng;Zheng, Wei;Ye, Peihuan
    • Steel and Composite Structures
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    • 제45권3호
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    • pp.369-388
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    • 2022
  • Composite effect between steel and recycled aggregate concrete (RAC) in steel reinforced-RAC (SRRAC) structures can effectively improve RAC's adverse mechanical properties due to the natural defects of recycled coarse aggregate (RCA). However, the performance of SRRAC after thermal exposure will have a great impact on the safety of the structure. In this paper, firstly, the mechanical properties of SRRAC structures after high temperatures exposure were tested, including 24 SRRAC columns and 32 SRRAC beams. Then, the change rules of beams and columns performance with the maximum temperature and replacement percentage were compared. Finally, the formulas to evaluate the residual bearing capacity of SRRAC beams and columns after exposure to high temperatures were established. The experimental results show that the maximum exposure temperature can be judged by the apparent phenomenon and mass loss ratio of RAC. After high temperatures exposure, the mechanical properties of SRRAC beams and columns change significantly, where the degradation of bearing capacity and stiffness is the most obvious. Moreover, it is found that the degradation degree of compression member is more serious than that of flexural member. The formulas of residual bearing capacity established by introducing influence coefficient of material strength agree well with the experimental results.

Effect of red ginseng NaturalGEL on skin aging

  • Kim, Ye Hyang;Park, Hye Rim;Cha, So Yoon;Lee, So Hun;Jo, Jung Wung;Go, Jung Nam;Lee, Kang Hyuk;Lee, Su Yeon;Shin, Song Seok
    • Journal of Ginseng Research
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    • 제44권1호
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    • pp.115-122
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    • 2020
  • Background: In aged skin, degradation of collagen fibers, which occupy the majority of the extracellular matrix in the dermis, and changes of aquaporin 3 (AQP3) and skin constituents, such as hyaluronic acid and ceramide, cause wrinkles and decrease skin moisturization to contribute to dryness and lower elasticity skin. Red ginseng (RG) is used as a cosmetic and food material and is known to protect from UVB-induced cell death, increase skin hydration, prevent wrinkles, and have an antioxidative effect. But, in general, RG used as a material is the soluble liquid portion in the solvent, and the part that is not soluble in the solvent is discarded. Thus, we made the whole RG into microgranulation and dispersed in water to produce gel form for using entire RG, and it was named red ginseng NaturalGEL (RG NGEL). Methods: RG NGEL was investigated for matrix metalloproteinases inhibitory activity, induction of Type I collagen, AQP3, hyaluronan synthetase 2, serine palmitoyl transferase, ceramide synthase 3, and filaggrin expression and compared with RG water extract. Results: RG NGEL reduced the levels of UV-induced matrix metalloproteinases and increased Type I collagen in human fibroblast cells and upregulated AQP3, hyaluronan synthetase 2, serine palmitoyl transferase, ceramide synthase 3, and filaggrin expressions in human keratinocytes compared with RG water extract. Conclusion: RG NGEL has the potential as an effective reagent for antiaging cosmetics to improve wrinkle formation and skin hydration.

Proteolysis of $\beta$-Catenin in Apoptotic Jurkat Cells

  • Hwang, Sang-Gu;Park, Jeong-Uck;Lee, Hyung-Chul;Joo, Woo-Hong;Cho, Yong-Kweon;Moon, Ja-Young
    • Journal of Life Science
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    • 제10권1호
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    • pp.57-63
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    • 2000
  • ${\beta}$-catenin, which plays a critical role in both the cytoskeleton and in transcriptional regulation in variousadherent cell types, undergoes degradation during adherent cell apoptosis. Although ${\beta}$-catenin has been reported to be present in Jurkat T-acute lymphoblastic leukemia cells, the regulation of ${\beta}$-catenin in hematologic malignancies have not been examined. The data presented here demonstrate that treatment of the T cell leukemia Jurkat iwht the apoptosis inducer anti-Fas induced proteolytic cleavage of ${\beta}$-catenin. ${\beta}$-catenin was cleaved at both the N- and C-terminus after anti-Fas treatment. Cleavage of intact ${\beta}$-catenin was completely inhibited by caspase selective protease inhibitors. These data demonstrate that ${\beta}$ -catenin proteolysis is triggered by the cross-linking of the Fas receptor on Jurkat cells and subsequent activation of caspase protease. There was a clear accumulatio of the large proteolytic fragment in Jurkat cells treated with lactacystin of ALLM. These are potent inhibitors of proteasome and calpain. these results suggest that both the proteasome and clapain may recognize the large ${\beta}$-catenin fragment as a substrate fot further degradation and that these pathewasy may act downstream of scapase in response to Fas receptor activation. Therefore, we suggest that ${\beta}$-catenin may play a role in promoting Jurkat survival.

Combination of Grapefruit and Rosemary Extracts Has Skin Protective Effect through MMPs, MAPKs, and the NF-κB Signaling Pathway In Vitro and In Vivo UVB-exposed Model

  • Yoon, Yeo-Cho;Choi, Hee-Jeong;Park, Ji-Hyun;Diniyah, Nurud;Shin, Hyun-A;Kim, Mi-Yeon
    • 한국자원식물학회지
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    • 제32권6호
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    • pp.633-643
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    • 2019
  • Long-term ultraviolet (UV) exposure accelerates the phenomenon of skin photo-aging by activating collagenase and elastase. In this study, we aimed to investigate the effects of a combination of grapefruit and rosemary extracts (cG&Re) on UVB-irradiated damage in HaCaT cells and dorsal mouse skin. In HaCaT cells, cG&Re recovered UVB-reduced cell viability and inhibited protein expression of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinases (p-Erk), c-Jun N-terminal kinases (p-JNK), and a class of MAPKs (p-P38). Also, cG&Re suppressed UVB-induced collagen and elastin degradation by decreasing matrix metalloproteinases (MMPs) and nuclear factor kappa light chain enhancer of activated B cells (NF-κB) expression, which is a transcription factor. Similar results were observed in dorsal mouse skin. Taken together, our data indicate that cG&Re prevent UVB-induced skin photo-aging due to collagen/elastin degradation via activation of MAPKs, MMPs, and the NF-κB signaling pathway in vitro and in vivo.

증기(蒸氣) 전처리(前處理)에 의(依)한 낙엽송(落葉松) 심재(心材)의 방부제(防腐劑) 처리도(處理度) 개선(改善)에 관(關)한 연구(硏究) (Studies on Improving Preservative Treatability of Japanese Larch Heartwood by Presteaming)

  • 강승모;백기현;김규혁
    • Journal of the Korean Wood Science and Technology
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    • 제25권1호
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    • pp.15-22
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    • 1997
  • The effectiveness of presteaming for improving CCA treatability on refractory Japanese larch heartwood was investigated in this study. Presteaming was effective on improving treatability, and the extent of improvement was dependent on moisture contents of wood specimen and steaming conditions. Green wood showed higher average value in both preservative retention and penetration than dry wood, and steaming under pressure conditions also had higher treatability than steaming at atmospheric conditions. The degree of improvement for treatability was increased with the extension of steaming period. Treatability of dry wood pres teamed under pressure conditions more than 6 hours and green wood for 3 hours was similar to that enhanced by conventional incising. Presteaming green wood under pressure conditions more than 6 hours was more effective than conventional incising in improvement of CCA treatability, and resultant treatability satisfied a minimum value required for CCA-treated wood for being used at the regions of hazard class H3 and H4. In addition, an improvement of treatability by presteaming was due to an increase in permeability resulted from the degradation of hemicelluloses within aspirated pit membrane and cell wall, not the removal of extractives from pit membrane. The reduction in strength, measured as longitudinal compressive strength, due to pres teaming was related with the degradation of hemicelluloses, and was increased as steaming conditions were severe. The degree of strength reduction associated with presteaming treatment to obtain required treatability could be quantified from the relatively good relation between the increase in treatability and the decrease in strength.

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고유진동수 시험을 통한 복합재 격자구조체의 유한요소모델 검증 (Verification of Finite Element Model for Composite Lattice Structures through Natural Frequency Test)

  • 임재문;신광복;이상우
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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    • pp.832-834
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    • 2017
  • 본 논문에서는 고유진동수 시험을 통해 복합재 격자구조체의 유한요소모델을 검증하였다. 복합재 격자구조체의 유한요소모델은 빔, 쉘 그리고 솔리드 요소를 사용하여 생성하였다. 고유진동수는 자유 경계조건 하에서 충격시험법을 사용하여 측정하였다. 쉘과 솔리드 요소의 유한요소해석 결과, 고유진동수 시험과 잘 일치하는 것을 확인하였다. 빔 요소는 섬유 비교차부의 물성저하를 고려하지 못하여 오차가 발생된 것으로 판단된다.

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Dose Dependency of Earthworm Powder on Antithrombotic and Fibrinolytic Effects

  • Kim, Yeong-Shik;Pyo, Mi-Kyung;Park, Kyung-Mi;Hahn, Bum-Soo;Yang, Kyung-Youl;Choi, Hye-Sook Yun
    • Archives of Pharmacal Research
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    • 제21권4호
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    • pp.374-377
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    • 1998
  • The freeze-dried powder of Lumbricus rubellus earthworm was administered orally to rats and its fibrinolytic and antithrombotic effects were investigated. The fibrinolytic activity of plasma was determined by measuring the plasmin activity of the euglobulin fraction and was increased to two-folds of the control at a dose of 0.5 g/kg/day and five times with 1 g/kg/day after 4-day administration. The antithrombotic effect was studied in an arterio-venous shunt model of rats. The thrombus weight decreased significantly from 43.2 mg to 32.4 mg at a dose of 0.5 g/kg/day after 8-day treatment. The level of fibrinogen/fibrin degradation product (FDP) in serum was elevated in a dose-dependent manner during the treatment period. On the 8th day after administration, the FDP value was increased to 7.7 $\mu\textrm{g}$g/ml compared with the control value of 3.3 $\mu\textrm{g}$g/ml. These results support that earthworm powder is valuable for the prevention and/or treatment of thrombotic conditions.

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High thermoelectric performance and low thermal conductivity in K-doped SnSe polycrystalline compounds

  • Lin, Chan-Chieh;Ginting, Dianta;Kim, Gareoung;Ahn, Kyunghan;Rhyee, Jong-Soo
    • Current Applied Physics
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    • 제18권12호
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    • pp.1534-1539
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    • 2018
  • SnSe single crystal showed a high thermoelectric zT of 2.6 at 923 K mainly due to an extremely low thermal conductivity $0.23W\;m^{-1}\;K^{-1}$. It has anisotropic crystal structure resulting in deterioration of thermoelectric performance in polycrystalline SnSe, providing a low zT of 0.6 and 0.8 for Ag and Na-doped SnSe, respectively. Here, we presented the thermoelectric properties on the K-doped $K_xSn_{1-x}Se$ (x = 0, 0.1, 0.3, 0.5, 1.5, and 2.0%) polycrystals, synthesized by a high-temperature melting and hot-press sintering with annealing process. The K-doping in SnSe efficiently enhances the hole carrier concentration without significant degradation of carrier mobility. We find that there exist widespread Se-rich precipitates, inducing strong phonon scattering and thus resulting in a very low thermal conductivity. Due to low thermal conductivity and moderate power factor, the $K_{0.001}Sn_{0.999}Se$ sample shows an exceptionally high zT of 1.11 at 823 K which is significantly enhanced value in polycrystalline compounds.