• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.186-194
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• 2006

Nitrogen dynamics of Seagrass Zostera marina were investigated in both Dongdae Bay and Ojiri from March to August, 2004. All seagrass samples were separated into four fractions such as leaves (new and adult), sheath and rhizome in order to understand temporal variations of nitrogen content in different fractions of Zostera marina. There are temporal variations of shoot production rates and total nitrogen contents in their different fractions at both study areas. Leaf production were almost 4 to 5 fold higher in summer than in winter. The irradiance is the primary factor controlling the leaf production of Zostera marina in both sites although water temperature also influence its productivity. Nitrogen contents of leaves were overall low in summer than in winter, but nitrogen content of rhizome increased during the summer season. In addition, nitrogen contents of new leaves were mostly higher than adult leaves in spite of lower nitrogen content of new and adult leaves in high productivity period. This result suggests that Zostera marina seems to have significant translocation ability of nitrogen in a shoot. The nitrogen content of leaf tissue may reflect nutritional nitrogen availability.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.9
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• pp.1323-1331
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• 2017

Objective: This study investigated the effect of extraction solvents on antioxidant bio-active compounds as well as potential antioxidant and lipid peroxidation inhibition of Phyllanthus acidus (P. acidus) leaf extract in minced pork. Methods: The effect of various solvent systems of water, 25%, 50%, 75% (v/v) ethanol in water and absolute ethanol on the extraction crude yield, total phenolic content, total flavonoid content and in vitro antioxidant activities of P. acidus leaves was determined. In addition, antioxidant activities of the addition of crude extract from P. aciuds leaves at 2.5 and 5 g/kg in minced pork on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical cation decolorization, reducing power and inhibition of lipid peroxidation (thiobarbituric acid reactive substances; TBARS) were determined. Moreover, sensory evaluation of the samples was undertaken by using a 7-point hedonic scale. Results: The results showed that the highest crude yield (2.8 g/100 g dry weight) was obtained from water which also had the highest recovery yield for total phenolic content, total flavonoid content and the strongest antioxidant activity. The addition of crude water extract from P. acidus leaves was more effective in retarding lipid peroxidation and higher antioxidant activity than control and butylated hydroxytoluene in minced pork. In particular, the samples containing P. acidus extract had no significant effect on the sensory scores of overall appearance, color, odor, texture, flavor, and overall acceptability compared to the control. Conclusion: Water solvent was an optimally appropriate solvent for P. acidus leaf extraction because of its ability to yield the highest amount of bio-active compounds and in vitro antioxidant property. Particularly, P. acidus crude water extract also strongly expressed the capacity to retard lipid oxidation, radical scavenging, radical cation decolorization and reducing power in minced pork. The results of this study indicated that P. acidus leaf extract could be used as natural antioxidant in the pork industry.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.377-384
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• 2009

Three-year-old seedlings of susceptible Pinus densiflora and resistant Pinus x rigitaeda were each inoculated with the pinewood nematode, Bursaphelenchus xylophilus, to compare disease development. Needle dehydration was evident on seedlings of P. densiflora by 20 days after inoculation, 10 days earlier than this symptom was observed on P. ${\times}$ rigitaeda. Xylem drying was more frequent in seedlings of P. densiflora than in that of P. ${\times}$ rigitaeda between 20 and 60 days after inoculation. No significant differences were found between P. densiflora and P. ${\times}$ rigitaeda for stem water content or for stem and leaf relative water content in current-year branches after nematode inoculation, but the average number of B. xylophilus recovered from stems differed significantly between the two groups. The number of B. xylophilus recovered from stems was negatively correlated with the stem water content and with stem and leaf relative water content. By the time the experiment was terminated at 60 days after inoculation, all 3 of the last group of P. densiflora seedlings had died, but 2 of the 3 remaining P. ${\times}$ rigitaeda hybrid seedlings were still alive. Additional studies are needed to further explore the specific mechanisms preventing nematode multiplication in the seedlings of resistant P. ${\times}$ rigitaeda.

• The Korean Journal of Ecology
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• v.9 no.4
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• pp.201-208
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• 1986

The water status of the leaves of several evergreen plants was investigated in order to discuss the geopgraphical distribution of them. Relastionship between relative water content and water potential of the leaves showed linear decrease for evergreen conifers but exponential decrease for Korean box tree (Buxus microphylla var. koreana). On the basis of the leaf water potential, the water status of the conifers during wintering was distinctly divided into three periods; hardening, cold resistance and dehardening, but lacking in those periods for the Korean box tree, where the status continously decreased. In the cold resistance the leaf water potentials were -23 bar for both spruce (Picea jezoensis) and yew (Taxus cuspidata). From these results and threshold temperature at beginning of hardening, distribution of the conifers was explained that in order of the red pine, the Korean white pine, the yew and the spruce the distribution could be extended at higher altitudes and in more northward areas, whereas the distribution of the Korean box tree was restricted to the lowland of temperate zone.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.5
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• pp.79-87
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• 2014

The enrichment with nutrients in rivers and lakes becomes serious problems in Korea. As the environmental friendly solution, the phytoremediation are getting more attention and the water hyacinth could be a strong candidate plant for this. Water hyacinth is a free floating freshwater plant proven to be a effective plant used for a purification of a polluted lakes, sewage wastewater, and livestock wastewater. The biggest obstacles for application of water hyacinth in Korea could be the disposal of the water hyacinth before winter, because there is no feasible use for the water hyacinth until now. In this study, the characteristics of water hyacinth were deeply investigated for providing background data to develop appropriate application of the water hyacinth. The water hyacinth was fractioned three parts, leaf, air blader, root of which morphological properties were evaluated with microscope and field emission scanning electron microscope (FE-SEM). The water contents of each parts of the water hyacinth were 87% for leaf, 96.5% for air bladder, 94.6% for root. The chemical compositions of each parts were also measured and showed around 29% of hot water extract in leaf and air bladder, 42% holocellulose for leaf, 47% holocellulose for air bladder. The application of water hyacinth biomass without root parts to papermaking provided bulkier structure, but the tensile strength was decreased.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.4
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• pp.322-329
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• 2015

Cirsium japonicum var. ussuriense are often used in treatment of human diseases such as hemorrhage, blood congestion and inflammation in Korea. However, there was not report on the anti-obesity efficacy of water extracts from different organs of C. japonicum var. ussuriense. Here, we investigated the antioxidant effects of water extracts of flowers, leaves and roots from C. japonicum var. ussuriense. Total polyphenol amounts of the flower extract showed higher than those of leaf and root extract. Flower extract also showed the high antioxidant activities such as DPPH radical scavenging activity and reducing power. We also investigated the anti-obesity effects of water extracts of flowers, leaves and roots from C. japonicum var. ussuriense in 3T3-L1 cells and high fat diet-induced obesity mice. The mice were divided into four groups [high fat diet (HFD) control, HFD + leaf extract, HFD + flower extract and root extract] and administered with each extract (200 mg/kg) for 12 weeks. The flower and leaf extract significantly suppressed the levels of oil red O and triglyceride content. The flower and leaf extract also significantly reduced the triglyceride, total cholesterol and lower density lipoprotein levels of plasma as well as body and abdominal fat weight. Furthermore, oral glucose tolerance in the flower and leaf extract groups were significantly ameliorated in comparison to the high fat diet group. Therefore, these results indicate that the flower and leaf extract could ameliorate obesity and attenuate blood glucose level in high fat diet-induced obesity mice. We conclude that this study may provide positive insights into water extracts of flowers and leaves from C. japonicum var. ussuriense as a functional food ingredient for treatment of obesity.

• Journal of Ginseng Research
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• v.4 no.1
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• pp.104-120
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• 1980

The effects of temperature on transpiration, chlorophyll content, frequency and aperture of stomata, and leaf temperature of Panax ginseng were reviewed. Temperature changes of soil and air under spade roof were also reviewed. Growth responses of responses of ginseng plant at various temperature were assessed in relation to suseptibillity of ginseng plants. Reasonable management of ginseng fields was suggested based on the response of ginseng to various temperatures. Stomata frequency may be increased under high temperature during leaf$.$growing stage. Stomata aperture increased by high temperature but the increase of both frequency and aperture appears not enough for transpiration to overcome high temperature encountered during summer in most fields. Serial high temperature disorder, i.e high leaf temperature, chlorophyll loss, inhibition of photosynthesis, increased respiration and wilting might be alleviated by high humidity and abundant water supply to leaf. High air temperature which limits light transmission rate inside the shade roof, induces high soil temperature(optimum soil temperature 16∼18$^{\circ}C$) and both(especially the latter) are the principal factors to increase alternaria blight, anthracnose, early leaf fall, root rot and high missing rate of plant resulting in poor yield. High temperature disorder was lessen by abundant soil water(optimum 17∼21%) and could be decreased by lowering the content of availability of phosphorus and nitrogen in soil consequently resulting in less activity of microorganisms. Repeated plowing of fields during preparation seems to be effective for sterilization of pathogenic microoganisms by high soil temperature only on surface of soils. Low temperature damage appeared at thowing of soils and emergence stage of ginseng but reports were limited. Most limiting factor of yield appeared as physiological disorder and high pathogen activity due to high temperature during summer(about three months).

• Korean journal of food and cookery science
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• v.11 no.4
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• pp.386-395
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• 1995

This study was carried out to investigate the volatile constituents change according to extraction methods, parts and heating methods. The research results are as follows: 23 kinds of components were extracted by steam distillation method; 8 by head space method; 16 by ether extraction method; 9 by Tenax-GC. This fact indicated that volatile constituents differ depending upon the extracting method. When the volatile constituents were extracted by steam distillation method and analyzed by GC-MSD, the content of the volatile constituents was 41.71 mg％ in the stem and 85.37 mg％ in the leaf. A total of 23 components - 14 kinds of hydrocarbon, 5 of aldehyde, 4 of alcohol- were detected in the stem. A total of 31 components - 21 kinds of hydrocarbon, 5 of aldehyde, 4 of alcohol and 1 of ester were detected in the leaf. The leaf had comparatively more varied volatile constituents than the stem. In the stem, the octanal content was highest and the contents of limonene, sabinene, -terpinene and -myrcene were higher; in the leaf, the content of octanal was highest and the contents of isobicyclogermacrene, limonene, -farnesene, undecaethiol, -terpinene, sabinene, elemene, -myrcen were higher. These were the major volatile constituents of the water d.opwort. The volatile constituent formation changed as the water dropwort was heated. The volatile constituents of the water dropwort heated in 1000 $m\ell$ were the most similiar to those of the raw water dropwort, and volatile constituent content was highest.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.175-180
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• 2003

Changes in biochemical constituents and physiological alteration were studied in various intensities (1-5%, 6-15%, 16-30%, 31-50% and ＞ 50%) of leaf spot (Myrothecium roridum) on mulberry leaves and compared with healthy leaves. Chlorophyll, total soluble sugar and total protein were decreased (P ＜ 0.01), but total phenol increased due to pathogen infection. Changes in biochemical constituents showed significant correlation with intensity of disease. Chlorophyll ($r^2$= 0.92), and protein (($r^2$= 0.83) possessed negative while phenol (($r^2$= 0.61) possessed positive correlation. Photosynthetic rate, transpiration rate, stomatal conductance, moisture content (%) and physiological water use efficiency (pWUE) were decreased, but stomatal resistance increased in the infected leaves. Physiological parameters also possessed significant (P ＜ 0.01) correlation with disease intensity. Photosynthetic rate (($r^2$= 0.96), transpiration rate ($r^2$=0.88), stomatal conductance (($r^2$= = 0.65), physiological water use efficiency (($r^2$= 0.88) and moisture content (r = 0.85) were negatively but stomatal resistance (($r^2$= 0.75) was positively correlated to disease intensities.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.204-210
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• 2011

This experiment was conducted to investigate the effect of water states (water, osmotic potential and turgor pressure) of fruit vesicle and leaf on soluble solids and organic acid contents of fruits of 'Shiranuhi' mandarin hybrid, M16 A line during the fruit maturing season in plastic house cultivation. The 'Shirauhi' grafted on 'Swingle citrumelo', strong strength of rootstock, produced fruit with lower soluble solids and organic acid content than 'Trifoliate' orange rootstock. The fruits vesicle water potential and turgor pressure measured before dawn in 'Swingle citrumelo' were higher tendency than the 'Trifoliate' orange, but osmotic potential values were lower than the 'Trifoliate' orange. The changes of leaf water potential were very similar to the fruit. The results suggest that in the 'Shirauhi' fruits grafted on two rootstocks changes of soluble solids and organic acid content of the fruit were influenced by the leaf water potential and the osmotic potential of the fruit vesicles, which might be caused by the difference of root distribution between two rootstocks.