• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.67-72
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• 2003

The leaves of D. racemosum showed strong DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and the order of the radical scavenging activity against DPPH radical is ethyl acetate (EtOAc) fraction>crude extracts>residue fraction>hexane fraction>ether fraction, under the experimental conditions. Since EtOAc fraction has highest antioxidative activity among these fractions, the isolation was performed from the EtOAc fraction of the leaves of D. racemosum and four phenolic compounds were isolated and identified as follows: methyl gallate, kaempferol, quercetin and quercitrin. The free radical scavenging activities of these compounds were 79.9%, 93.1%, 93.6% and 66.7% at 10 ㎍/ml, respectively. The IC₅₀ of compound 1, compound 2, compound 3 and compound 4 were 6.1, 4.1, 3.6 and 6.5 ㎍/ml, respectively. These compounds have higher antioxidative activity compared with reference compounds, ascorbic acid (IC₅₀ = 9.6 ㎍/ml).

• Biomaterials and Biomechanics in Bioengineering
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• 제1권1호
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• pp.27-39
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• 2014

We have previously described a new multilayer alginate microcapsule system, and the goals of the present study were to assess the in vitro function of islets encapsulated in its inner layer, and the angiogenic ability of FGF-1 delivered from the external layer in an omentum pouch. Following isolation and culture, islets were encapsulated in the inner core of microspheres ($500-600{\mu}m$ in diameter) with a semi-permeable poly-L-ornithine (PLO) membrane separating two alginate layers, and both unencapsulated and encapsulated islet function was assessed by a dynamic glucose perifusion. For angiogenesis experiments, one group of microcapsules without FGF-1 (control) and another (test) containing FGF-1 with heparin encapsulated in the external layer were made. One hundred microcapsules of each group were transplanted in Lewis rats (n = 5/group) and were retrieved after 14 days for assessment of angiogenesis. Glucose perifusion of unencapsulated and encapsulated islets resulted in similar stimulation indices. The release of FGF-1 resulted in increased vascular density compared to controls. In conclusion, islets encapsulated in the core of multilayer alginate microcapsules maintain functionality and the microcapsule's external layer is effective in delivery of FGF-1 to enhance graft neovascularization in a retrievable omentum pouch.

• 한국환경생태학회:학술대회논문집
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• 한국환경생태학회 2011년 학술대회 논문집
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• pp.87-89
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• 2011

• Applied Microscopy
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• 제37권4호
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• pp.281-287
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• 2007

The genus Hypoxylon is a member of the Xylariaceae that has brown to dark brown and phaseoliform single cell ascospores with a conspicuous full germ slit. Hypoxylon truncatum differs from H. annulatum, it has conspicuous perithecial mounds, dark brown stromatal surface, and absence of enriched ostiola disc. The isolate of Hypoxylon, collected from Mt. Deuk-yu in Korea, is compared with similar taxa and described. The isolation of H. truncatum is compared with similar taxa, H. annulatum, with a precise description in the SEM level in Korea.

• 한국산림과학회지
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• 제96권5호
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• pp.515-519
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• 2007

An imperfect fungus Fusiococcum species was isolated from Quercus dentata. A naturally infected Daimyo oak tree was collected and showed elongate wounds on the stem. The fungal cultures were initially white and cottony, and later turned dark gray. Numerous solitary pycnidia were developed on the medium surface, and typically spherical. Yellowish conidial masses were exuded from pycnidia on the culture plates. Conidial masses were swollen and measured as approximately 100 to $300{\mu}m$ in length. It appeared that conidia were usually held together in globose to oval drops. Conidia were hyaline, single-celled (nonseptate), ellipsoid to fusoid, and measured as approximately $8.0{\times}2.7{\mu}m$. Based on these cultural and morphological characteristics, the fungal isolate was identified as a species of Fusicoccum Corda. To preserve and examine fungal spores exuded from pycnidia on the medium surface, a vapor fixation procedure for scanning electron microscopy was employed in this study. The specimens were exposed to the vapor of 2% (v/v) glutaraldehyde and 2% (w/v) osmium tetroxide each for 2 h. With the vapor fixation we obtained excellent retention of conidial masses in this study. The simple and versatile procedure for demonstrating fungal spores and their exudation from fruiting bodies would facilitate characterization of diverse pathological and environmental isolates as they are in native environments.

• 펄프종이기술
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• 제43권5호
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• pp.60-67
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• 2011

Hemicelluloses pre-extracted from Korean mixed wood chip were investigated as a wet-end additive. Hemicelluloses dissolved in hot water and alkali solution were isolated by ethyl alcohol precipitation from pre-extractives. They showed molecular weight of 9,000 ~ 27,000 g/mol as revealed by size exclusion chromatography. The reduction of molecular weight through hot water extraction was caused by autohydrolysis. Chemical composition of the hemicelluloses were analyzed with high-performance liquid chromatography and UV-Vis spectroscopy. As the surface charge of isolated hemicelluloses were negative, the adsorption of hemicelluloses onto softwood unbleached kraft pulp fiber was promoted by poly-DADMAC. The physical properties of handsheets increased as the molecular weight of hemicellulose increased. On the other hands, the optical property decreased with hemicellulose adsorption.

• 한국산림과학회지
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• 제74권1호
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• pp.29-36
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• 1986

이태리포푸라 I-214 (Populus euramericana cv. I-214)의 기내배양(器內培養)한 엽육조직(葉肉組織)에서 원형질체(原形質體) 분리(分離)에 미치는 몇가지 요인(要因)에 대(對)해 조사(調査), 검토(檢討)하였다. 기내(器內)에서 배양(培養)된 아(芽)를 다량(多量)으로 증식(增植)하기 위한 배지(培地)는 MS 기본배지(基本培地)에 $0.1mg/{\ell}$의 BAP를 첨가(添加)한 것이 가상 좋은 성적을 나타냈다. 엽(葉) 1g 당(當) $2.4{\times}10^6$개의 가장 높은 원형질체(原形質體) 분리(分離) 빈도를 나타낸 것은 Cellulase R-10 2 %, Macerozyme R-10 0.8 %, Hemicellulase 1.2 %, Driselase 2.0 %, Pectolyase Y-23 0.05 %에 DTT와 MES 완충액을 첨가(添加)한 후 삼투압 안정제로 0.6 M의 Mannitol을 넣고 pH를 5.6으로 조정한 효소용액(酵素溶液)이었다. CPW 용액(溶液)으로 세정(洗淨)한 후 0.6 M의 Sucrose 용액(溶液)에 처리(處理)한 것이 회수율(回收率) 51.8 %로 가장 높게 나타났다.

• 인간식물환경학회지
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• 제21권6호
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• pp.557-564
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• 2018

Along with the aging society, the prevalence of dementia is also increasing. Dementia causes short-term memory loss as well as difficulties of performing daily activities and gradually causes suffering of the patients and their family. In spite of various programs for prevention of dementia of older people are being implemented, there is a lack of developing natural-based program for physical and mental health promotion. Therefore, it is necessary to develop programs for the elderly living alone who are more vulnerable to dementia because of their social and economic isolation. The purpose of this study was to develop a natural-based program and investigate the effects of 10 weeks forest therapy program for dementia prevention to improve the psychological and physical health of the elderly living alone. The experimental subjects were 30 elderly (aged 65 or older) and 31 elderly participated in control group. The Stress response, depressive symptoms, weight, body mass index (BMI), fat mass and muscle mass were measured for pre and post test. The results showed that the experimental group showed subjective stress relief (t=5.249, p=.000), improvement in symptoms of depression (t=4.152, p=.000), and decreases in weight (t=2.686, p=.012), BMI (t=2.629, p=.014) and fat mass (t=2.918, p=.007) after the forest therapy program. The experimental group showed lower stress reactions(t=-7.185, p=.000) and less depressive symptoms (t=-5.303, p=.000) than control group after participating the program. These results suggest that periodic forest exposure can help having less stressful and depressive status than non-forest exposure and the forest therapy program can reduce participants' psychological and physical risk factors of dementia.

• 한국산림과학회지
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• 제73권1호
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• pp.33-42
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• 1986

현사시 (Populus alla${\times}$P. glandulosa)의 기내배양(器內培養) 엽육조직(葉肉組織)으로부터 원형질체(原形質體)의 분리(分離) 및 배양(培養)을 시험하였다. 무균(無菌)의 엽육조직(葉肉組織)을 육성(育成)하기 위한 shoot의 대량증식에는 MS기본배지에 BAP 0.4 mg/l을 첨가하였을 때 가장 증식효과가 높았으며, 원형질체(原形質體)의 분리(分離)를 위한 효소농도는 Cellulase 2%, Macerozyme 0.8%, Hemicellulase 1.2%, Driselase 2%, Pectolyase Y-23 0.05%가 가장 효과적이었다. 효소용액의 삼투압은 mannitol 0.6 M이 적합하였으며, pH는 5.6이 적절하였다. 원형질체(原形質體)의 안정성을 높이기 위하여 DTT와 MES buffer를 첨가하여 좋은 결과를 얻었다. 분리(分離)된 원형질체(原形質體)의 정제를 위해서는 부유용액(浮遊溶液)의 sucrose 농도를 0.6M로 하였을 때가 가장 적합하였으며 dextran의 첨가효과도 높았다. 본 연구의 특징은 다소 높은 농도의 효소용액을 처리하여 단시간에 원형질체(原形質體)를 분리(分離)하는 것으로서 이 방법에 의해 나출(裸出)된 원형질체(原形質體)의 배양(培養)에 있어서 반응여부를 조사한 결괴 배양 3주 후에까지도 좋은 반응을 보였다.

• 한국산림과학회지
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• 제94권4호통권161호
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• pp.236-242
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• 2005

다양한 광조건에서 식물의 생장조절에 관여하는 광수용체인 phytochrome B(PhyB) 유전자를 교잡종 포플러 수항1호에서 분리하였다. 염기서열분석 결과, PhyB cDNA는 길이가 3,456bp 이었으며 1,156개의 아미노산으로 구성된 단백질을 암호화하고 있는 것으로 나타났다. PhyB 단백질은 아미노산 수준에서 Populus balsamfera PhyB1과 98%의 높은 상동성을 나타내었다. Northern blot 분석 결과, PhyB 유전자는 광조건에서는 높은 수준으로 발현되지만, 암조건에서는 발현되지 않는 것으로 나타났다. 본 연구의 결과들을 종합하여 볼 때 PhyB는 빛에 의하여 발현이 유도되며 광수용체 역할을 하는 것으로 여겨진다.