• Journal of the Korean Wood Science and Technology
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• 제34권5호
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• pp.1-10
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• 2006

The objective of this study was to elucidate the microscopic patterns of decay caused by brown-rot fungi of Tyromyces palustri and Gloeophyllum trabeum in Korean red pine (Pinus densiflora) and radiata pine (Pinus radiata) woods through light and electron microscopies. The ultrastructural changes of cell walls attacked by the two brown-rot fungi were compared in this respect. Macroscopically, radiata pine showed more ring and radial checks than Korean red pine. Microscopically, with the progress of decay, spiral checks associated with cross-field pits and bore holes in the cell wall were more remarkably numerous in the radiata pine than in the Korean red pine. In the radiata pine, G. trabeum produced more spiral checks in the cell wall than T. palustris. In the advanced stages of decay by G. trabeum, the erosions of ray cell walls were identified both in the Korean red pine and radiata pine but $S_3$ layers of tracheid walls were eroded only in the Korean red pine.

• 한국환경성돌연변이발암원학회지
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• 제19권1호
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• pp.56-62
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• 1999

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) has been considered to be as one of major antioxidants present in grapes responsible for beneficial effects of red wine consumption on coronary heart disease. This triphenolic stilbene has been suggested as a potential cancer chemopreventive agent based on its striking inhiitory effects on diverse cellular events associated with tumor initiation, promotion, and progression. The compound has strong antioxidative and anti-inflammatory activities which amy contribute to its chemopreventive/chemoprotective properties. In the present work, we have found that resveratrol reduces viability and DNA synthesis capability of cultured human promyelocytic leukemia (HL-60) cells. Likewise, the viability of human breast cancer cell line, MCF-7 was reduced by resveratrol treatment. The growth inhibitory and antiproliferative properties of resveratrol appear to be associated with its induction of apoptotic cell death as determined by morphological and ultrastructural changes, agarose gel electrphoretic analysis of internucleosomal DNA fragmentation, and in situ terminal end-labeling of fragmented DNA (TUNEL). This compound also inhibited the phorbol ester-induced expression of cyclooxygenase-2 (COX-2) protein in immortalized human mammary epithelial MCF-10A cells. These results suggest that resveratrol has the promising cancer therapeutic/chemopreventive potential.

• The Plant Pathology Journal
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• 제34권3호
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• pp.218-235
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• 2018

Plant growth promoting rhizobacteria and endophytic bacteria were isolated from different varieties of turmeric (Curcuma longa L.) from South India. Totally 50 strains representing, 30 PGPR and 20 endophytic bacteria were identified based on biochemical assays and 16S rDNA sequence analysis. The isolates were screened for antagonistic activity against Pythium aphanidermatum (Edson) Fitzp., and Rhizoctonia solani Kuhn., causing rhizome rot and leaf blight diseases in turmeric, by dual culture and liquid culture assays. Results revealed that only five isolates of PGPR and four endophytic bacteria showed more than 70% suppression of test pathogens in both assays. The SEM studies of interaction zone showed significant ultrastructural changes of the hyphae like shriveling, breakage and desication of the pathogens by PGPR B. cereus (RBacDOB-S24) and endophyte P. aeruginosa (BacDOB-E19). Selected isolates showed multiple Plant growth promoting traits. The rhizome bacterization followed by soil application of B. cereus (RBacDOB-S24) showed lowest Percent Disease Incidence (PDI) of rhizome rot and leaf blight, 16.4% and 15.5% respectively. Similarly, P. aeruginosa (BacDOB-E19) recorded PDI of rhizome rot (17.5%) and leaf blight (17.7%). The treatment of these promising isolates exhibited significant increase in plant height and fresh rhizome yield/plant in comparison with untreated control under greenhouse condition. Thereby, these isolates can be exploited as a potential biocontrol agent for suppressing rhizome rot and leaf blight diseases in turmeric.

• Journal of Plant Biology
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• 제38권3호
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• pp.275-280
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• 1995

The formation of osmiophilic globules related to the granal lysis has been investigated with a shade plant ginseng (Panax ginseng C. A. Meyer) exposed to full sunlight. The changes of chloroplast were examined as a function of time over 9 days under full sunlight exposure. The ultrastructure of ginseng leaf showed swelling of the granal thylakoid during an early stage of the light exposure. The thylakoid membrane faded and small electron-opaque dots were aggregated on the edges of the granal thylakoid membrane when the exposure time was increased over 1 day. Then, the sahpe of the grana changed into round. After the exposure over 3 days, there appeared many osmiophilic globules with multi-lamellated concentric structure. The globules at this stage were partly accumulated with osmiophilic substances. The outermost membrane of these multi-lamellated osmiophilic globules was attached to the stromal thylakoid membrane connecting to the deforming grana. The osmiophilic globules were elongated after 9 days. In this stage, the multi-lamellated structure was difficult to identify due to severe accumulation of osmiophilic substances. The number of the osmiophilic globules also increased along with the full sunlight exposure time. This observation leads us to believe that the multi-lamellated osmiophilic globules came from the deformation of grana.

• The Journal of Korean Physical Therapy
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• 제16권2호
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• pp.63-71
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• 2004

Denervated skeletal muscle produces muscle atrophy as well as changes at the neuromuscular junction which leads to terminal axonal sprouting and an ultrastructural remodeling. NT-3 is expressed in adult muscle and motoneurons. Normally NT-3 has a potential role in regulating adult neuromuscular jungtion and recovering following muscle atrophy. Also, it could influence synaptic neurotransmission between motoneurons and skeletal muscle cells. The purpose of this study was to investigate the effect of electrical stimulation therapy(EST) on NT-3 expression in neuromuscular junction following sciatic nerve transsection in rats. After EST application during 7 days, the immunoreactivity of NT-3 was increased in neuromuscular junction

• 대한수의학회지
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• 제19권1호
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• pp.33-44
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• 1979

Herpes virus인 소의 전염성 비기관염 바이러스와 악성 카탈열 바이러스의 형태(形態)와 그 형성과정(形成過程)(형태발생(形態發生))을 조직배양(組織培養)에서 각기 시험(試驗)하였다. 이 두 종류(種類)의 바이러스는 herpes virus의 특징적(特徵的)인 구조(構造)를 가지나 그 형태발생(形態發生)이 상이(相異)함을 밝혔다. 1. 소의 전염성비기관염(傳染性鼻氣管炎) 바이러스 (IBRV/CT3) 배양에서 그 바이러스의 envelope는 세포질막(細胞質膜)으로부터 유래(由來)됨을 밝혔다. 2. IBRV/CT3 배양에서 envelope는 가진 바이러스는 세포핵내(細胞核內)에는 전혀 나타나지 않았다. 3. 소의 악성(惡性)카탈열(熱) 바이러스(MCFV/C500)의 배양에서 그 바이러스의 envelope는 세포핵막(細胞核膜)으로부터 유래(由來)됨을 밝혔다. 4. 소의 악성(惡性)카탈열(熱) 바이러스(MCFV/C500)에 감염(感染)된 토끼의 폐장(肺臟)에서 얻은 macrophage에 대해 바이러스의 소재(所在)를 추구(追究)한바, 이 바이러스는 macrophage의 세포질내(細胞質內)에만 존재(存在)함을 밝혔다. 그리고 이 바이러스는 탐식(貪食)된 바이러스임을 알았다.

• Applied Microscopy
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• 제19권2호
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• pp.43-58
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• 1989

To investigate the effects of hexavalent chromium on mitochondrial respiration of rat kidney, various hexavalent chromium concentrations were treated, then respiration and electron transfer enzyme activities were measured. Ultrastructural changes at state IV respiration of mitochondria were also observed. Then, to investigate protective role against hexavalent chromium in the body, low-molecular-weight, chromium-binding substances (LMCr) were purified from livers of rabbits 2hr after intravenously administrated with sodium dichromate at a dose of 74mg per kg body weight. And then, respiration rates of mitochondria treated with LMCr, hexavalent chromium containing 0.7mM chromium were measured. Hexavalent chromium decreased state IV respiration rates and electron transfer enzyme activities of mitochondria, and increased labile membrane and swelling. And partial inhibitions of condensed to orthodox conformational change were observed. Respiration rates of mitochondria treated with LMCr containing 0.7mM chromium did not differ from that of the non-treated mitochondria. But respiration rates of 0.7mM hexavalent chromium-treated mitochondria decreased by 42%, compared to non-treated mitochondria. These results suggest that LMCr may play an important role in detoxification of toxic hexavalent chromium.

• Applied Microscopy
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• 제22권2호
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• pp.127-140
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• 1992

This research was undertaken to determine the effects of the cyclophosphamide (CP) on the epididymal corpus of the male rat in terms of ultrastructural alteration and protein analysis by SDS-PAGE at different groups; control group, 1 week group, 3 weeks group and 5 weeks group were treated with saline (control group) or CP at doses of 20mg/kg/week, 1 time a week, respectively. In the cytoplasm of the principal cells on the epididymal corpus, the mitochondria were significantly swollen or disrupted. The lumens of rough endoplasmic reticulum (rER) were also dilated and the number of secretory vesicles and lysosomes were increased respectively. CP caused changes in protein concentrations in the corpus of epididymis after CP treatment. Total proteins of 31 to 36 species were expressed in the corpus fluid. Then the more CP was increased, the more concentration of proteins caused to decrease, synthesize or increase in epididymal corpus. In contrast to the control group, in particular 88KD and the other 8 proteins in the corpus fluid, were decreased or disappeared respectively, whereas acid phosphatase and the other 9 proteins in the corpus fluid, were increased or synthesized respectively. The other proteins are not showed distinctive difference. It is suggested that treatment with CP alters the specific cell organelles and proteins in segment of the epididymal corpus.

• 보존과학회지
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• 제1권1호
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• pp.3-11
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• 1992

Micromorphological changes in waterlogged archaeological woods excavated from Sweden and Germany were investigated. Especially bacterial attacks on those wood samples under near anaerobic conditions were examined by transmission electron microscopy(TEM). The major feature of micromorphological alterations in those wood samples was the preferential destruction of secondary wood cell wall. In contrast, the middle lamella was not extensively degraded. Three distinct degradation patterns by bacteria were observed : erosion, cavitation and tunnelling bacteria. Erosion and cavitation bacteria attacked primarily $S_2$ layer, whereas tunnelling bacteria made the tunnel-like degradation along the $S_1$ layer. Tunnelling bacteria, in some samples, were able to degrade tunnel in the lignin-rich areas, such as middle lamella, suggesting that these bacteria had the capacity to degrade the lignin. IR spectra indicate that hemicellulose and cellulose in the waterlogged woods were preferentially decomposed. Breakdown of the lignin, on the other hand, was much slower.

• 한국식품영양과학회지
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• 제20권6호
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• pp.637-645
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• 1991

Physicochemical factors affecting cooking and eating quality of rice and their mechanisms were investigated. The stickiness of cooked rice was negatively correlated with amylose content(r=0.58, p<0.05) and protein content(r=-0.72, p<0.01), but not affected by crude fat content of rice. The ultrastructure of cooked rice grain showed the progressive gelatinization of starch from the periphery toward the center of the endosperm as water and heat energy diffused into. The rate of water diffusion appears to be dependent on the cell arrangement in the endosperm and the protein content of milled rice. Once water and heat reach the starch granules, the rate of in situ gelatinization of starches appears to be dependent on their own gelatinization temperature range and amylose content. Protein acts as a barrier for the swelling of starch and water diffusion in two ways : 1) by encasing starch granules in the starchy endosperm, and 2) by forming a barrier between the subaleurone layer and the starchy endosperm. Therefore, the separation and fragmentation of the outermost layers of the endosperm occurred more easily in the low-protein content rices, and was associated with increases of solids lost in cooking-water at 95$^{\circ}C$ and stickiness of cooked rice.