• 제목/요약/키워드: Kt factor

검색결과 83건 처리시간 0.024초

남한의 산림생태계에 있어서의 낙엽의 분해모델 (A Model for Litter Decomposition of the Forest Ecosystem in South Korea)

  • Park, Bong Kyu;In Sook Lee
    • The Korean Journal of Ecology
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    • 제4권1_2호
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    • pp.38-51
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    • 1981
  • The present investigation was estimated the effect of temperature, precipitatiion, and time on the decomposition of litters with litter bags of Pinus densiffora and Quercus mongolica at Gure where elevation in 50m, and at Nogodan where elevation in 1300m on Mt. Jiri. As the above results, decomposition model was proposed to relation of the environmental conditions. And was investigated the production and decomposition of litters from the stands of various forest communities in Kwangneung, Mt. Jiri and Mt. Halla. The results are as follows; The models for the decay of organic carbon (C) was as follows: $C=Coe^{-Kt}$ (limiting factor;time) $C=Coe^{-K'te}$ (limiting factor;tempedrature) $C=Coe^{-KnP}$ (limiting factor:precipitation) As observed in litter bag method, the decomposition rate of litter in Pinus densiflora was slower than that of Quercus mongolica. The higher elevation, the slower decomposition rate. The decomposition of litters at Gure where elevation in 50m was equally influenced by temperature and precipitation. But at Nogodan where elevation in 1300m was much inflenced by precipitation. The decay constant of litters was larger in hardwood forest than in coniferous forest. In the same species, the more elevatiion, the less decomposition constant. The time required for the decay of 50%, 95^, 99% of the accumulated litters in the forest floor were faster in hardwood forest than in coniferous forest. In the same species, the higher elevatiion, the longer time required.

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전방십자인대 재건술 후 스포츠 활동 복귀 (Return to Sports Activity After Anterior Cruciate Ligament Reconstruction)

  • 박종혁;이준모;배현경;임종한;이주홍
    • 대한정형외과스포츠의학회지
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    • 제8권2호
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    • pp.95-101
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    • 2009
  • 목적: 전방 십자 인대 재건술을 시행한 환자에서 수상 전 스포츠 활동으로의 복귀 정도와 관여 인자를 알아보았다. 대상 및 방법: 2003년 9월부터 단일 다발 전방십자인대 재건술을 시행받은 109명의 환자 중 스포츠 손상으로 2년 이상 추시 가능한 43예를 대상으로 수상 전 스포츠 활동으로의 복귀 여부를 조사하였다. 평균 나이는 26세(17~45세)였고, 추시 기간은 평균 31.2 개월(24~53개월)이었다. 수술 전과 최종 추시에서의 임상적 결과는 Lysholm 점수, Tegner 활동 수준 척도, 객관적 및 주관적 International Knee Documentation Committee questionnaires (IKDC 평가표), KT-1000 관절계를 이용하여 평가하였다. 결과: 임상적 결과는 술 전에 비해 최종 추시에서 모두 유의하게 호전되었다(P<0.001). 43예 중 25예(58%)는 수상 전 운동으로 복귀하였으나 18예(42%)는 복귀에 실패하였다. 복귀에 실패한 환자에서 11예(61%)는 재부상에 대한 두려움, 나머지 7예(39%)는 불안정과 통증을 이유로 복귀하지 못하였다. ANOVA test상 세 환자 군의 Lysholm 점수, 주관적 IKDC 평가표, 및 KT-1000 검사에서 통계적으로 유의하였다(P<0.001). 그러나 수상 전 스포츠 활동으로 복귀한 군과 재부상에 대한 두려움 때문에 복귀하지 못한 두 군에서는 Lysholm점수와 KT-1000 검사 상 유의한 차이가 없음에도 불구하고 Tegner 활동 수준, 주관적 IKDC 평가표에서 유의한 차이를 보였다(P<0.001). 결론: 스포츠 손상으로 전방십자인대 재건술을 받은 환자들 중 약 25%에서 재손상에 대한 두려움으로 인해 수상 전 스포츠 활동으로 복귀하지 못했다. 전방십자인대 재건술의 성공적인 결과를 위해서는 재건술 술기 향상과 체계적인 재활 방법이 여전히 요구되지만 심리적인 요인에 대한 고려 역시 필요할 것으로 생각된다.

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고려홍삼으로부터 분리한 compound K 함유분획에 의한 대식세포의 toll-like receptor-의존성 신호전달로 활성조절 분석 (Compound K (CK) Rich Fractions from Korean Red Ginseng Inhibit Toll-like Receptor (TLR) 4- or TLR9-mediated Mitogen-activated Protein Kinases Activation and Pro-inflammatory Responses in Murine Macrophages)

  • 양철수;고성룡;조병구;이지연;김기혜;신동민;육재민;손현수;김영숙;위재준;도재호;조은경
    • Journal of Ginseng Research
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    • 제31권4호
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    • pp.181-190
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    • 2007
  • 본 연구에서는 고려홍삼으로부터 새로 분리한 CK 함유분획을 이용하여 마우스 대식세포에 대한 선천면역반응 조절에 미치는 영향을 조사하였다. 본 연구에서 사용된 농도의 CK 함유분획에서는 세포독성 효과가 관찰되지 않았으며 CK함유 분획의 전처리에 의하여 그람음성세균의 LPS, 또는 CpG-ODN에 의해 유도되는 NF-${\kappa}B$와 MAPK 활성 및 전염증성 사이토카인, NO의 분비가 TLR4 및 TLR9 특이적으로 억제되었다. 이와 같은 결과는 CK 함유분획이 TLR4을 매개로하는 염증반응뿐만 아니라 TLR9을 통한 염증반응에도 영향을 미치는 것으로 해석된다. 따라서 앞으로 CK 함유 분획에 포함된 개별 사포닌 등 시료 성분에 대한 면밀한 분석, 그리고 이들 개별 물질이 각각의 신호전달 체계에 미치는 영향과 그 기작에 대한 연구가 더욱 필요할 것으로 사료되며 염증억제제로서의 개발 가능성을 탐구하기 위한 생체 내에서의 효능 및 작용기전 분석이 요구된다.

분광용매화 구리(II) 착물에 의한 메탄올 이성분 혼합용매들의 Donor Number (Donor Number of Mixed MeOH Solvents Using a Solvatochromic Cu(Ⅱ)-Complex)

  • 유승교;김진성;사공열
    • 대한화학회지
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    • 제36권6호
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    • pp.796-801
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    • 1992
  • 분광용매화 기질인 [Cu(tmen)(acac)]$CIO_4$를 이용하여 혼합용매의 Lewis basicity인 Gutmann의 Donor Number(DN)를 측정하였다. 측정된 여덟가지 MeOH 혼합용매들의 DN값 변화는 단순히 용매의 조성변화와 일치하지 않을 뿐만 아니라, 혼합용매들은 그 변화 형태에 따라 세 개의 그룹으로 구분할 수가 있었다. (1) 기질에 대한 용매화가 주로 cosolvent들에 의해 이루어지는 경우(MeOH-DMSO, MeOH-PY, MeOH-DMF)와 (2) 기질의 용매화에 혼합용매의 두 성분이 거의 동일하게 영향을 미치는 경우 (MeOH-MeCN, MeOH-dioxane, MeOH-AC) 및 (3) 전적으로 MeOH에 의한 기질의 용매화가 이루어지는 경우이다(MeOH-DCE, MeOH-TCE). 또한 순수한 용매들의 경우와 마찬가지로 이들 혼합용매들에 대한 DN과 Kamlet-Taft의 basicity 변수인 $B_{KT}$값들간에는 비교적 좋은 상관관계성을 볼 수 있었으며, 혼합용매들의 반응성 해석에서도 유용한 인자로 사용될 수 있음을 알았다.

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Protopanaxadiol modulates LPS-induced inflammatory activity in murine macrophage RAW264.7 cells

  • Lee, Whi-Min;Kim, Sung-Dae;Kim, Kil-Soo;Song, Yong-Bum;Kwak, Yi-Seong;Cho, Jae-Youl;Park, Hwa-Jin;Oh, Jae-Wook;Rhee, Man-Hee
    • Journal of Ginseng Research
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    • 제30권4호
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    • pp.181-187
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    • 2006
  • Protopanaxadiol (PPD) is a mixture of protopanaxadiol type saponins with a dammarane skeleton, from Korean red ginseng (Panax ginseng C.A. Meyer; Araliaceae). Korean ginseng is well-known herb to treat almost all kinds of diseases in Oriental medicine. This herb was particularly prescribed for treatment various inflammatory diseases, including rheumatoid arthritis, atherosclerosis, and diabetes mellitus, for centuries. To understand the efficacy of ginseng against inflammatory diseases, we aimed to show anti-inflammatory activities of the PPD in murine macrophage cell line, RAW264.7 cells using nitric oxide (NO) production assay and the expressions of pro-inflammatory cytokines, such as tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), interleukin-$1{\beta}$ (IL-$1{\beta}$), and IL-6, and monocyte chemotactic protein-1 (MCP-1). We found that PPD saponin significantly blocked LPS ($1{\mu}g/ml$)-induced NO production in a dose-dependent manner. In addition, PPD abrogated the expressions of LPS-induced pro-inflammatory cytokines, such as IL-$1{\beta}$ and MCP-1. Moreover, cyclooxygenase (COX)-2, a critical enzyme to produce prostaglandin E2 (PGE2), was significantly inhibited by PPD in LPS-activated RAW264.7 cells. Taken together, these results suggested that anti-inflammatory efficacy of Korean red ginseng on inflammatory diseases is, at least, due to the NO inhibitory activity and the inhibition of the expressional level of inflammatory cytokines and/or mediators.

Drosophila melanogaster 한국지반에서 분리한 KP Elements의 DNA 염기서열 분석 (Molecular Analysis of KP Elements Derived from Korean Populations of Drosophifa mefanogaster)

  • Kim, Wook;Kim, Jeong-Soo;Shin, Dong-Jik
    • 한국동물학회지
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    • 제39권2호
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    • pp.164-172
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    • 1996
  • KP elements derived from Korean populations (Seoul, Cheonan and Taegu) of Drosophila melunoguster were examined for their molecular structure. The entire 1.15 kb sequence of the three KP elements KC-137 (Cheonan), KS-95 (Seoul) and KT-99 (Taegu) have been obtained by PCR amplification using inverted repeat primers and DNA sequencing. The 1.15 kb fragments of KP elements were cloned into pCRmll vector plasmids, and subsequently sequenced. The sequence of the three KP elements in these populations suggested that there might have been derived from the complete P element by a 1753 bp internal deletion between positions 808 and 2560. Therefore these KP elements were confirmed to be identical to that isolated from M'10 strains widely distributed in most Eurasian populations of D. melanoguster. Sequence comparison with the 2.9 kb complete P element in pn25.1 revealed that KC-137 has only shown to be two base substitutions of A to G and G to A at positions 62 and 242, respectively. The retained sequence of the two KP elements KS-95 and KT-99 shows complete homology to the P factor in pn25.1. Based on this result, the two base substitutions in KC-137 might be due to Taq DNA pollunerase errors. Finally, it is suggested that the high copy numbers of KP elements provieds an explanation for the suppression of P-mediated hybrid dvssenesis in Korean population of D. melunogoster.

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PC 12 세포의 Apoptosis에 대한 성향정기산의 방어효과 및 작용기전 연구 (The Neuroprotective Mechanism of Sunghyangjunggisan Water Extracts on Apoptosis of PC 12 Cell)

  • 최철원;이인;이기상;조남수;문병순
    • 대한한의학회지
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    • 제23권1호
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    • pp.50-60
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    • 2002
  • Objectives: Sunghyangjunggisan (SHJS) is a commonly prescribed drug with a wide neuropharmacological spectrum. The water extracts of SHJS were found to be protective against neurotoxicity elicited by deprivation of serum and glucose. Methods: The morphological examination and Hoechst staining of nucleus also clearly showed that the extracts attenuated the cell shrinkage, membrane blebbing, representing typical neuronal apoptotic phenomena and nucleosome-sized fragmentation under the microscope in PC 12 rat pheochromocytoma cells. Results: Activation of protein kinase A (PKA) with dibutyl-cAMP and forskolin also protected during glucose deprivation, although it was not additive with the effect provided by phorbol ester. Interestingly, treatment with the protein kinase A inhibitor, KT5720, was not neuroprotective in the presence of SHJS. Electrophoretic mobility shift assays were used to characterize the neuroprotective binding of nuclear proteins to consensus sequences for AP-l, nuclear factor kappa B ($NF-{\kappa}B$) after glucose deprivation. When PC 12 cells are induced to undergo apoptosis by serum deprivation, AP-l and $NF-{\kappa}B$ DNA binding activity transiently increases to a slight degree. This stimulation is blocked by the water extracts of SHJS. The site of action of the drugs appeared to involve specific inhibition of AP-1 and nuclear factor kB binding activity. Conclusions: Taken together, these results suggested the possibility that the extracts of SHJS might provide a neurotrophic-like activity in PC 12 cells.

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근래의 신장이식 임상성적과 관련인자들: 단일기관 연구 (Clinical Outcomes and Contributors in Contemporary Kidney Transplantation: Single Center Experience)

  • 안재성;박경선;박종하;정현철;박호종;박상준;조홍래;이종수
    • 대한이식학회지
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    • 제31권4호
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    • pp.182-192
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    • 2017
  • Background: In recent years, introduction of novel immunosuppressive agents and its proper implementation for clinical practice have contributed to improving clinical outcomes of kidney transplantation (KT). Here, we report clinical outcomes of KTs and related risk factors. Methods: From July 1998 to June 2016, 354 KTs (182 from living and 172 from deceased donors) have been performed at Ulsan University Hospital. We retrospectively reviewed the clinical characteristics and outcomes of KT recipients, then estimated graft and patient survival rate were estimated and analyzed risk factors using Cox-regression. Results: The median follow-up period was 53 months (range; 3 to 220 months). The mean ages of recipients and donors were 45.0 years (SD, 12.5) and 44.7 years (SD, 13.6) years, respectively. During follow-up, 18 grafts were lost and 5- and 10-year death-censored graft survival was 96.7% and 91.5%, respectively. Biopsy-proven acute rejection (BPAR) occurred in 71 patients (55 cases of acute cellular rejection and 16 of antibody-mediated rejection). Cox-regression analysis showed that BPAR was a risk factor related to graft loss (hazard ratio [HR], 14.38; 95% confidence interval [CI], 3.79 to 54.53; P<0.001). In addition, 15 patients died, and the 5- and 10-year patient survival was 97.2% and 91.9%, respectively. Age ≥60 years (HR, 6.03; 95% CI, 1.12 to 32.61; P=0.037) and diabetes (HR, 6.18; 95% CI, 1.35 to 28.22; P=0.019) were significantly related to patient survival. Conclusions: We experienced excellent clinical outcomes of KT in terms of graft failure and patient survival despite the relatively high proportion of deceased donors. Long-term and short-term clinical outcomes have improved in the last two decades.

A Genetically Encoded Biosensor for the Detection of Levulinic Acid

  • Tae Hyun Kim;Seung-Gyun Woo;Seong Keun Kim;Byeong Hyeon Yoo;Jonghyeok Shin;Eugene Rha;Soo Jung Kim;Kil Koang Kwon;Hyewon Lee;Haseong Kim;Hee-Taek Kim;Bong-Hyun Sung;Seung-Goo Lee;Dae-Hee Lee
    • Journal of Microbiology and Biotechnology
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    • 제33권4호
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    • pp.552-558
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    • 2023
  • Levulinic acid (LA) is a valuable chemical used in fuel additives, fragrances, and polymers. In this study, we proposed possible biosynthetic pathways for LA production from lignin and poly(ethylene terephthalate). We also created a genetically encoded biosensor responsive to LA, which can be used for screening and evolving the LA biosynthesis pathway genes, by employing an LvaR transcriptional regulator of Pseudomonas putida KT2440 to express a fluorescent reporter gene. The LvaR regulator senses LA as a cognate ligand. The LA biosensor was first examined in an Escherichia coli strain and was found to be non-functional. When the host of the LA biosensor was switched from E. coli to P. putida KT2440, the LA biosensor showed a linear correlation between fluorescence intensity and LA concentration in the range of 0.156-10 mM LA. In addition, we determined that 0.156 mM LA was the limit of LA detection in P. putida KT2440 harboring an LA-responsive biosensor. The maximal fluorescence increase was 12.3-fold in the presence of 10 mM LA compared to that in the absence of LA. The individual cell responses to LA concentrations reflected the population-averaged responses, which enabled high-throughput screening of enzymes and metabolic pathways involved in LA biosynthesis and sustainable production of LA in engineered microbes.

압출가공방법에 의한 PZT세라믹스-고분자 압전복합재료의 제조 및 특성 연구 (Study on the Preparation of the Piezoelectric Composite Materials in PZT Ceramics-Polymers by Extrusion Method and its Properties)

  • 이덕출;김진수
    • 한국세라믹학회지
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    • 제27권1호
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    • pp.74-78
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    • 1990
  • In this study, to develope the ultrasonic transducer element, the extrusion method which is the processing technique of the piezoelectric composite materials is introduced, the connectivity of the piezoelectric composite materials is the 1-3 type, and we study the properties of the materials. The electromechanical coupling factor(kt) of the materials is above 0.6, the resonance property(fr) is the thickness mode in the frequency range of 0.5 to 2 [MHz] and the acoustic impedance(Zac) is about 5 to 7 [Maryl]. From these results, it is known that the piezoelectric composite materials manufactured byt he extrusion method will be able to develope the ultrasonic transducer elements.

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