• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.15-22
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• 2009

Adequate environment conditions with growth stage of potato were decided in a photoautotrophic micropropagation system using models. Total 20 day-period of growth were divided into three growth periods such as 6 (stage 1), 7(stage 2), and 7(stage 3) days. At the 1st stage, no significant differences were observed in the growth of potato plantlets at various photosynthetic photon flux density (PPFD) and $CO_2$ conditions. Considering damaged leaves, $80\;mmol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and ambient $CO_2$ level were adequate in this stage. At the 2nd stage, significant differences were partly observed in several growth characteristics including dry weight. Based on the dry matter model, over $240\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD was too high to cultivate potato plantlets at this stage due to the occurrence of damaged leaves. Considering both plant growth and energy efficiency, $160\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and $700\;mol{\cdot}mol^{-1}\;CO_2$ were selected for the adequate combination. At the 3rd stage, the biomass accumulation was significantly induced in potato plantlets under higher levels of PPFD and $CO_2$ concentration as suggested by increased fresh and dry weights. However, we could not find the saturated point with regard to dry matter due to continuous increase of dry mater even under maximum PPFD ($320\;mmol{\cdot}m^{-2}{\cdot}s^{-1})$. Thus, $320\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and $1800\;mol{\cdot}mol^{-1}\;CO_2$ were considered as the best choice at final stage in this study. In conclusion, even though the growth period of micropropagated potato plantlets was quite a short, favorable environmental conditions required at each growth stage were different. This technique could improve the growth of micropropagated plantlets compared to the conventional micropropagation and apply to other agriculturally important crops as well as potato in the future.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.56-63
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• 2017

This study was carried out to establish qualities of watermelon seedling (Citrullus lanatus) according to raising seedling period (RSP; 40, 45, 50, 55, 60, and 65 days) and was carried out to investigate growth characteristics after planting of the seedlings. In seedling qualities according to RSP, Plant height, stem diameter, leaf area of seedling with RSP 65 treatment were significantly increased. Fresh and dry weight in the above of corp showed a significant difference among the seedlings with RSP 40-45, RSP 50-60 and RSP 65 treatment, and that in of root were significantly higher in the seedlings with RSP 40, 45, 65 treatments than with other RSP treatments. S/R ratio was lower in the seedlings with RSP 40 and 45 treatments than with other RSP treatments. RSP affected to the leaf area and S/R ratio of seedling. After 11 weeks after planting of a various seedlings, except that height and node number of plant with 45 RSP treatment was lower than other RSP treatments, other growth characteristics were not significantly different amon RSP treatments. Leaf area, fresh weight, dry weight and S/R ratio were lowest in plant with RSP 65 treatment. Relative growth rate and net assimilation rate of planted watermelon tended to decrease and leaf area ratio was continuously increased until 9th week in the all treatments. The lighter and heavier fruit were produced in plants with RSP 40 and RSP 65 treatments (9.7 kg and 9.9 kg) and in RSP 50 and RSP 55 treatments (both 11.0kg), respectively. Fruit sugar contents was highest in fruit with RSP 45 treatment, and was lowest in RSP 50 and RSP 60 treatments. RSP showed a polynomial regression relation with the increment of fruit weight and the weight of harvested fruit. Considering the increment and weight of fruit, the most for RSP of watermelon seedling for planting were 50-55 days.

• Journal of Chest Surgery
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• v.38 no.7 s.252
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• pp.461-467
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• 2005

Pleura, diaphragm, pericardial fat pad, intercostal muscles and omentum can be used to protect and revascularize the bronchial suture line of tracheal transplantation, lung transplantation and pulmonary resection. The purpose of the present study is to compare the influence of the pleura, diaphragm and omentum in survival of isolated tracheal segments in the experimental animals. Material and Method: Sprague-Dawley rats weighing 250- 350g were used. The animals were divided in three groups; the pleura, omentum and diaphragm. Following intraperitoneal anesthesia, endotracheal intubation was performed. Then the trachea was exposed. A three-ring sec- tion of cervical trachea was excised. The resected trachea was implanted at each sites. After 2 weeks, rats were sacrificed. Histopathological examination of the tracheal segments was performed. For comparison of each groups, histopathological viability of resected tracheal segment was scored by three tissue layers; epithelium, submucosa, and cartilage. The results were presented as average score. Result: In histopathological examination, submucosa and cartilage using tracheal segment necrosis scoring system. The pleural group showed well preserved tissue. There was minimal necrosis and inflammation compared with other groups. In the pleural group, tracheal necrosis scores were $2.17\pm0.983$at epithelium, $1.67\pm0.516$ at submucosa and $2.17\pm0.753$ at cartilage. At the omental group, scores were $1.00\pm0.00,\;1.60\pm0.548\;and\;1.80\m0.447$. In the diaphragmatic group, scores were $1.40:\pm0.894,\;2.40\pm0.547\;and\;2.20\pm0.447$. Total necrosis score were $6.00\pm1.789$ in the pleural group, $4.40\pm0.894$ in the omental group and $6.00\pm1.414$ in the diaphragmatic group. Conclusion: There were no significant viability differences in terms of total necrosis score for the viability of resected tracheal segment. But the best result was achieved in the omental group. Therefore, omental wrapping on tracheal graft site will be beneficial for the prevention of graft necrosis.

• Korean Journal of Weed Science
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• v.10 no.4
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• pp.269-276
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• 1990

Weed species belonging to the broadleaf family prevailed in the experimental sites followed by Cyperucea and grass family. In terms of life cycle, the dominant weed species were the perennial weeds rather than annual weeds. Most of weeds were emerged between 30-60days after transplanting in Chuncheon and between 40-60 days after transplanting in Hongcheon and Hoengseong areas. Among agronomic characteristics of rice affected by weed emergence were decrease of plant height by 2-4㎝, panicle number by 1.3-2.9, spkelet by 3. 7-7.5, ripening rates by 3.3-6.5%, and milled yield by 12-17%.

• Korean Journal of Weed Science
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• v.10 no.2
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• pp.83-92
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• 1990

Experiment was conducted to establish the weed control system on the paddy fields by investigating species, period and amount of weeds in Gangwon province. Four locations were selected for these experiments : West plain area, Chunchon(74m above the sea level), mid-mountainous area, Hongchon(300 m), high alpine area, Hoengsong(450m), and east sea area, Myungju(14m). Weed emergence was investigated 6 times from 10 days after transplanting to 60 days with 10 days interval. From the experiments stated above, the results were summarized as follows ; The identity of weed species was small in grass family, but broad-leaf family was numerous. Also the dominant weed species was generally the perenial weeds. The weed emergence was initiated from 10 days after translanting. The amounts of weed counted the most in Chunchon. A large number of weeds were emerged between 30-60 days after transplanting in Chunchon and between 40-60 days after transplanting in Hongchon and Hoengsong. Among agronomic characteristics affected by weed emergence during rice development, plant height was decreased by 2~4cm, panicle number by 1.3~2.9, spikelet by 3.7~7.5, ripening rates 3.3~6.5%, and milled yield by 12~17%, respectively.

• Korean Journal of Weed Science
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• v.9 no.3
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• pp.201-213
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• 1989

About 233 weed species belonging to 54 families mainly occurring in summer were observed in cultivated land and its surrounding area in Cheju Island. The compositae was the most widely occurring family covering 41 weed species, followed by 28 species in gramineae, 14 in labiatae, 13 in leguminasae and 12 in polygonaceae etc.. In terms of the lands classified about 126 species in 39 families were observed in upland ared and 38 species in 20 families occurred in lowland area, 108 species in 36 families in orchard and 214 species in 50 families observed in non-cultivated area. The most dominant weed species in Cheju Island were Portulaca oleracea, Digitaria sanguinalis in both the upland and orchard, Monochoria vaginalis, Cyperus amuricus in lowland, and Digitaria sanguinalis, Artemisia princeps, Partulaca oleracea in non-cultivated land area. There were two communities in upland area, such as Phyllanthus urinaria, Siegesbeckia orinexitalis etc., and Cephalonaplos segetum, Mosla dianthera etc.. The lowland area composed of one major community like Onenanthe javanica, and Eleocharis acicularis. The orchard consisted of the communities of Stellaria aquatics, Viola mandshurica etc., and Justicia procumbens, Varedellia crustacea etc.. The non-cultivated land composed of two major communities like Amplicarpaed edgeworthii, Lactuca indica etc., and Clematis appiiforia, Aster hispidus etc..

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.221-228
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• 2011

Weed control is of fundamental importance when planting horticultural crops, particularly during the establishment phase. Weeds compete for nutrients, water and light, and can severely threaten the survival and early growth of newly planted crops. Failure to control weeds represents one of the single most important factors leading to crop loss. Knowledge on the existence of the diversity of weed species in greenhouses is of our main concern in this study in order to develop a most efficient and effective weed control strategies. Sixty-two greenhouses were surveyed in 3 cities and counties of Gyeongnam area in March to October 2009 to investigate the feature of weed occurrence in polyvinyl chloride (PVC) after harvesting of the main crops. Forty-one weed species were identified and classified to 18 families which were composed of 14 annual weeds, 18 summer annual weeds and 9 perennial weeds. On the other hand, broadleaf, grasses and sedges recorded with 30, 7 and 4 weed species, respectively. Asteraceae was the most dominant weed species (9 species) noted followed by Poaceae (7 species), Cyperaceae (4 species), Caryophyllaceae and Brassicaceae (3 species respectively) and other families have 1~2 species. The dominant weed species occurred in the greenhouse based on the summed dominance ratio. These weeds were Digitaria sanguinalis, Cyperus iria, Portulaca oleracea, Rorippa islandica, Mazus japonicas, Cardamine flexousa, and Eclipta prostrata and others. Weed occurrence in the greenhouse after horticultural crops consisted of summer annuals (4 species), winter annuals (3 species), and perennial annuals (1 specie). The dominant species occurred in tilled soil based on summed dominance ratio of weeds were Cardamine flexousa (88.1%), Eclipta prostrate (57.4%) and Portulaca oleracea (55.2%). Comparison of weed occurrence was thoroughly surveyed also in which field without PVC, weed species were Portulaca oleracea (55.2), Eclipta prostrata (57.9%) and Trigonotis peduncularis (25.1%) and field with PVC, the identified weeds were Portulaca oleracea (98.75), Trigonotis peduncularis (49.1%), and Eclipta prostrata (36.8%).

• Weed & Turfgrass Science
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• v.6 no.2
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• pp.86-108
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• 2017

The nationwide weed survey was conducted in arable land, paddy field, upland, orchard and pasture, over whole country of Korea during 3 years from 2013 to 2015. Also, these survey were conducted in order to determine a change of weed community and to identify a major dominant weed species, and problem weeds. Weeds of arable land were composed of 619 species belonging to 81 families. Weeds occurred in paddy field were 90 species belonging to 28 families, upland weeds were 375 species of 50 families, orchard weeds were 492 species of 63 families and pasture weeds 275 species of 52 families. Among total 81 families, the Asteraceae (15.5%) was the biggest family, followed by Poaceae (13.1%), Fabaceae (5.5%), Cyperaceae (5.2%), Polygonaceae (6.3%), respectively. And these weed species were composed of annual weeds of 209 species (33.8%), winter annual of 102 species (16.4%) and perennial weeds of 308 species (49.8%). Exotic weeds naturalized in Korea were investigated as 166 species. Weed flora in Korean cultivation area have been increased as much as 13 families and 186 species for 10 years compared to 2000~2004 weed survey result of 68 families and 433 species. The increment could be resulted from the change of weed population such as increase of the herbicide-resistant and the difference of investigation method.

• Journal of Life Science
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• v.25 no.1
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• pp.101-112
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• 2015

A type of cell junction that is formed between different parts within the same cell is called autotypic cell junction. Autotypic junction proteins form tight junctions found between membrane lamellae of a cell, especially in myelinating glial cells. Some of them have postsynaptic density-95/disks large/zonula occludens-1 (PDZ) domains, which interact with the carboxyl (C)-terminal PDZ-binding motif of other proteins. PDZ domains are protein-protein interaction modules that play a role in protein complex assembly. The PDZ domain, which is widespread in bacteria, plants, yeast, metazoans, and Drosophila, allows the assembly of large multi-protein complexes. The multi-protein complexes act in intracellular signal transduction, protein targeting, and membrane polarization. The identified PDZ domain-containing proteins located at autotypic junctions include zonula occludens-1 (ZO-1), ZO-2, pals-1-associated tight junction protein (PATJ), multi-PDZ domain proteins (MUPPs), membrane-associated guanylate kinase inverted 2 (MAGI2), and protease-activated receptor (PAR)-3. PAR-3 interacts with atypical protein kinase C and PAR-6, forming a ternary complex, which plays an important role in the regulation of cell polarity. MAGI2 interacts with ${\alpha}$-amino-3-hydroxyl-5-methyl-4-isoxazole propionate (AMPA) receptor at excitatory synapses. PATJ is detected in paranodal loops associated with claudin-1. On the other hand, MUPP1 is found in mesaxons and Schmidt-Lanterman incisures with claudin-5. ZO-1, ZO-2, and PAR-3 are found at all three sites. Different distributions of PDZ domain-containing proteins affect the development of autotypic junctions. In this review, we will describe PDZ domain-containing proteins at autotypic tight junctions in myelinating Schwann cells and their roles.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.159-175
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• 2015

Surveys of weed species on upland fields were conducted in Korea to investigate the occurrence of weed flora from April to May 2014 for winter crop fields and from July to August 2014 for summer crop fields. From the nation-wide survey, 375 weed species in 50 families were identified and classified to 162 annuals, 78 biennials and 135 perennials. Based on the occurrence ratio, the most weed species belonged to Compositae (73 species). 44 and 25 weed species belonged to Poaceae and Polygonaceae, respectively, and these 183 weed species in the most five families accounted for 49% of total weed occurrence. While 287 weed species in 45 families occurred in the winter crop fields, 339 weed species in 47 families occurred in summer crop fields. The most dominant weed species in Korean upland fields were Digitaria ciliaris, followed by Portulaca oleracea, Acalypha australis, Chenopodium album, Rorippa palustris etc. 129 weed species in 25 families were considered as exotic weeds. Based on the importance analysis, the highest value was C. album followed by Amaranthus lividus, Conyza canadensis etc. This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in upland fields of Korea.