• Korean Journal of Environmental Agriculture
• /
• v.17 no.2
• /
• pp.174-181
• /
• 1998

In four citrus grow of Satsuma mandarin (rootstock of trifoliate orange) including two grove of organical management and two groves of conventional management, spores of arbuscular mycorrhizal(AM) fungi were identified and seasonal changes in spore density in soils and AM colonization of citrus roots were investigated. AM colonization in weeds found in the groves were also examined. Three species of Glomus (G.deserticola, G. vesiculiferum, G. rubiforme ) and one unknown species of Acaulospora were observed in all of the groves. Annual mean density of AM fungal spores were in the range of 10,000${\sim}$40,000 per 100g soil with more spores in the organically-managed groves. The least spores were observed in December in all groves, and the most spores in April in the organically-managed groves while in February or April in the conventionally- managed. Annual mean AM colonization more 27% of citrus root were observed in the organically-managed with the high peaks in April and October and the minimum in August, while mean colonization less than 15% in the conventionally-managed with the peak in February and the minimum in different times depending on groves and years. AM colonization corresponded to a sigmoidal curve consisting of a laf phase during winter and a subsequent increase in spring, then succeeded by a maximum, and then a decrease at the end of vegetation. Fungal spore density and AM colonization showed a parallel pattern during the sample period. The seasonality appeared to be related more to the phenology of the plant than to the soil factors. Generally more spore density and AM colonization were found in organically managed groves. AM colonization was not correlated with available P and organic matter content in soil in this field investigation. Among sixteen weed species found in the groves, Astrogalus sinicus of Leguminosae, Portulaca oleracea of Portulacaceae showed high colonization in all groves and they can be considered as a source of inoculumn and host plants for propagation of AM fungi.

• Journal of Preventive Medicine and Public Health
• /
• v.13 no.1
• /
• pp.3-12
• /
• 1980

Certain heavy metals which may lead peoples to poisonous status are widely used in industry and their uses have been increasing along with rapid industrialization of this country. Such an increasement of metal uses aggravates the status of environmental pollution affecting foodstuffs which are the most important life supporting factor of animal and humanbeing. Concerning the safety measures to minimize food-borne transmission of such hazardous metals, surveillance is the backbone of them and probably more so with a potential problem such as intoxication. Theoretically, this surveillance should include the determination of levels of heavy metal toxicants in foods, the determination of food consumption patterns and typical total diet, and the estimation of total load of the metal contaminant from all sources of exposure including air, water, and occupational sources. In recent year, actually, such estimates on the total daily intake of some heavy metals from foods have been made in several developed countries and a wide variation of date by season, locality, and research method was recognized. Also in this country, this kind of research data is vitally needed to make up for the serious shortage or lack of references to estimate the total amount of heavy metal intake of the people. In this study, a modification model for estimation of the total daily intake of cadmium copper, nickel, zinc, and lead through foods was applied and concentrations of the above metals in crops cultivated in this country were measured with atomic absorption spectro photometer to get the following results. 1. Level of heavy metal concentration in crops Generally, the levels of such metals in essential crops such as rice, cucumber, radish. chinese cabbage, apple, pear, grape, and orange are similar or lower than those in Japan and other developed countries. By the way, a striking result on cadmium concentration was increasement of its concentration in rice from $0{\sim}0.035ppm$ in 1970 to 0.11ppm in this study. However, the value is still far below the. Japanese Permissible Lebel of 1.0ppm. 2. Estimation of total daily intake per capita from foods A new model for estimation was devised utilizing levels of metal concentration in foods, amount of food consumed, and other food factors. Based on the above method, the daily intake of cadmium was estimated to be $70.53{\mu}g/man/day$ in average which was as high as the Limit Value of ILO/WHO(up to $71.4{\mu}g/man/day$). Also, 3.89mg of Zinc, 1.65mg of cuppor, 0.32mg of lead were given as the total daily intake per capita by this research. 3. Efficacy of washing or skinning to decrease the amount of metals in crops After washing the crops sufficiently with commercial linear alkylate sulfonate, the concentration of heavy metals could be reduced to $50{\sim}80%$ showing decreasement rate of $20{\sim}50%$. Also, after skinning the fruits, decreasement rate of the heavy metal concentration shelved $0{\sim}50%$.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.1
• /
• pp.197-205
• /
• 2017

Exposure of Jurkat T cell clone (J/Neo cells) to acacetin (5,7-dihydroxy-4'-methoxyflavone), which is present in barnyard millet (Echinochloa esculenta (A. Braun)) grains, caused cytotoxicity, enhancement of apoptotic $sub-G_1$ rate, Bak activation, loss of mitochondrial membrane potential (${\Delta}{\Psi}m$), activation of caspase-9 and caspase-3, degradation of poly(ADP-ribose) polymerase, and FITC-Annexin V-stainable phosphatidylserine exposure on the external surface of the cytoplasmic membrane without accompanying necrosis. These apoptotic responses were abrogated in Jurkat T cell clone (J/Bcl-xL) overexpressing Bcl-xL. Under the same conditions, cellular autophagic responses, including suppression of the Akt-mTOR pathway and p62/SQSTM1 down-regulation, were commonly detected in J/Neo and J/Bcl-xL cells; however, formation of acridine orange-stainable acidic vascular organelles, LC3-I/II conversion, and Beclin-1 phosphorylation (Ser-15) were detected only in J/Neo cells. Correspondingly, concomitant treatment with the autophagy inhibitor (3-methyladenine or LY294002) appeared to enhance acacetin-induced apoptotic responses, such as Bak activation, ${\Delta}{\Psi}m$ loss, activation of caspase-9 and caspase-3, and apoptotic $sub-G_1$ accumulation. This indicated that acacetin could induce apoptosis and cytoprotective autophagy in Jurkat T cells simultaneously. Together, these results demonstrate that acacetin induces not only apoptotic cell death via activation of Bak, loss of ${\Delta}{\Psi}m$, and activation of the mitochondrial caspase cascade, but also cytoprotective autophagy resulting from suppression of the Akt-mTOR pathway. Furthermore, pharmacologic inhibition of the autophagy pathway augments the activation of Bak and resultant mitochondrial damage-mediated apoptosis in Jurkat T cells.

• Korean Journal of Ichthyology
• /
• v.10 no.1
• /
• pp.1-10
• /
• 1998

The early history of Korean mandarin fish, Siniperca scherzeri was studied to obtain some information required in aquaculture and reinforcement of natural population. During the period from June 1996 to July 1997, the mature adults of Siniperca scherzeri were collected from the middle Soyang Lake at Puksan - myon, Chunchon - shi, Kangwon - do, Korea. The eggs from females were obtained by injecting HCG or/and GnRH - a and fertilized by dry method in the laboratory. The fertilized eggs, measuring 1.70~2.10 mm in diameter and expanded to 2.20~2.66mm after absorption of water, were globosity, light orange yellow, separative, submergence and had one large oil globules of 0.5~0.7 mm. The blastodisc was formed in 1 hour and cleavage started in 1 hour 30 min. after fertilization, and the intervals of each stage of cleavage was about 50 min. at the water temperature of $21{\sim}24^{\circ}C$. Hatching occurred 131 hours 30 min. after fertilization and newly hatched larvae were 5.86~6.85 mm in total length(TL) and numerous stellate melanophores were distributed on the yolk and abdomen of caudal peduncle. The yolk was almost absorbed and the teeth development. 3 days after hatching, at 6.98~7.60 mm TL. The head spines and the teeth were largely developed and all fins were completely formed and became postlarva stage 15 days after hatching, at 10.10~12.90 mm TL. The body shape and the color pattern were similar to adult, 25 days after hatching, at 15.3~23.8 mm TL. In 5 months after hatching were reached at 154.10~175.02 mm TL and 49.32~82.67 g in body weight.

• Korean Journal of Microbiology
• /
• v.44 no.1
• /
• pp.43-48
• /
• 2008

Standard sample for quality control of total coliform measurement was procured by addition of nalidixic acid and cephalexin as bacteriostatic agents to Escherichia coli cultured broth. After making the standard sample, the number of E. coli was measured by fluorescence microscopic count method and plate count method by 12 hr interval. The numbers of E. coli remained unchanged for at least for 48 hr at room temperature which ranged from 3.5 to $4.2{\times}10^5\;cells/ml$ and from 1.0 to $1.2{\times}10^4\;CFU/ml$ by direct fluorescence microscopic count method and plate count method, respectively. This result suggests that microbial standard sample with bacteriostatic agents of nalidixic acid and cephalexin is usable for quantitative quality control.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.11 no.1
• /
• pp.25-30
• /
• 1982

To evaluate the quality of commercial dehydrated tea-products, the relationships between particle sizes, densities, moisture absorption & desorption and color appearance were studied by using Hunter-lab tristimulus colorimeter and spectrophotometer. Among the tea-products was held no significant relation between particle sizes and color appearance but red ginseng extract powder (RGEP) was included L, a and b values when was reduced particle size. appearance color of tea-products indicated red-orange color, L, a and b values were ranged 32.7 to 48.0, 4.0 to 10.0 and 5.6 to 18.0, respectively, densities of tea-products ranged 0.232 to 0.898 g/ml and increased L values, Hunter's a/b ratio values was included in 0.61 to 0.90. Color stability in this products was well agreed with decrease of total color difference value ($\Delta$E) and chromaticity difference value ($\Delta$C) of the Hunter-lab color data.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.3
• /
• pp.547-552
• /
• 2002

To investigate an efficacy of mixed extract with Ginseng radix, Puerariae lobata, Puerariae radix, Rubi pructus, Gomi pructus, Hoelen, Dried orange peel and Parvum comus cervi etc., on the hangover elimination, 12 hr-fasted male Sprague-Dawley rats weighing 150-200 g were given mixed extract (5 mL/kg, p.o.) and administered ethanol at a dose of 3 g/kg bw (25% in distilled water) orally 30 min postdosing. Blood was collected from caudal artery at 0.25, 0.5, 1, 2, 4, 6, 8, 10, and 12hr and then the animals were sacrificed at 24hr after the ethanol treatment. In these experiments, liver function indices, such as alanine aminotransferase and alkaline phosphatase activities, showed unaltered results in all treated groups compared with the normal group. The pharmacokinetics of ethanol after oral administration of mixed extract were also evaluated. From 0 min to 12hr, the administration of mixed extract showed 14% reduction of the area under the serum concentrations-versus-time curves (AUC) compared with the control group. The activities of alcohol dehydrogenase and aldehyde dehydrogenase measured at 24hr postdosing were also not altered by the administration of mixed extract compared with the control group. These studies demonstrate that oral administration of mixed extract, prepared by traditional prescription, decreases the ethanol concentration in serum and reduces AUC, suggesting that the mixed extract is effective for elimination of ethanol-induced hangover.

• Korean Journal of Materials Research
• /
• v.30 no.8
• /
• pp.406-412
• /
• 2020

SrMoO₄:RE³⁺ (RE=Dy, Sm, Tb, Eu, Dy/Sm) phosphors are prepared by co-precipitation method. The effects of the type and the molar ratio of activator ions on the structural, morphological, and optical properties of the phosphor particles are investigated. X-ray diffraction data reveal that all the phosphors have a tetragonal system with a main (112) diffraction peak. The emission spectra of the SrMoO₄ phosphors doped with several activator ions indicate different multicolor emissions: strong yellow-emitting light at 573 nm for Dy³⁺, red light at 643 nm for Sm³⁺, green light at 545 nm for Tb³⁺, and reddish orange light at 614 nm for Eu³⁺ activator ions. The Dy³⁺ singly-doped SrMoO₄ phosphor shows two dominant emission peaks at 479 and 573 nm corresponding to the ⁴F_9/2→⁶H_15/2 magnetic dipole transition and ⁴F_9/2→⁶H_13/2 electric dipole transition, respectively. For Dy³⁺ and Sm³⁺ doubly-doped SrMoO₄ phosphors, two kinds of emission peaks are observed. The two emission peaks at 479 and 573 nm are attributed to ⁴F_9/2→⁶H_15/2 and ⁴F_9/2→⁶H_13/2 transitions of Dy³⁺ and two emission bands centered at 599 and 643 nm are ascribed to ⁴G_5/2→⁶H_7/2 and ⁴G_5/2→⁶H_9/2 transitions of Sm³⁺. As the concentration of Sm³⁺ increases from 1 to 5 mol%, the intensities of the emission bands of Dy³⁺ gradually decrease; those of Sm³⁺ slowly increase and reach maxima at 5 mol% of Sm³⁺ ions, and then rapidly decrease with increasing molar ratio of Sm³⁺ ions due to the concentration quenching effect. Fluorescent security inks based on as-prepared phosphors are synthesized and designed to demonstrate an anti-counterfeiting application.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.22 no.2
• /
• pp.73-77
• /
• 2012

Co-(0.8 wt%) and Ce-(0.4 wt%) doped cubic zirconia ($ZrO_2$ : $Y_2O_3$ = 80 : 20, 70 : 30, 60 : 40, 50 : 50 wt%) single crystals grown by a skull melting method were heat-treated in $N_2$ at $1000^{\circ}C$ for 5 hrs. The orange, yellowish brown and brown colored as-grown single crystals were changed into either brownish red, yellow and green color after the heat treatment. Before and after the heat treatment, the YSZ (yttria-stabilized zirconia) single crystals were cut for wafer form (${\phi}6.5mm{\times}t2mm$). The optical and structural properties were examined by UV-VIS spectrophotometer and X-ray diffraction. Absorption by $Ce^{3+}(^2F_{5/2,7/2}(4f){\rightarrow}^2T_g(5d^1))$, $Co^{2+}(^4A_2(^4F){\rightarrow}^4T_1(^4F)$ or $^4T_1(^4P))$ and $Co^{3+}$, change of ionization energy and lattice parameter were confirmed.

• Journal of the Korean Chemical Society
• /
• v.18 no.5
• /
• pp.381-388
• /
• 1974

When mixture of p-phenylenediamine (PPD) and m-aminophenol (MAP) were reacted with formaldehyde (F) varying their amounts under $N_2$ stream at the temperature of -5∼0$^{\circ}$, addition condensation reaction occurred and brown colored resins(in some cases orange colored) were formed immediately. All resins thus formed were insoluble in most ordinary organic solvents and did not melt up to 300$^{\circ}$. When the resins were treated with dilute(7 %) aqueous sodium hydroxide solution, the adsorptivity of methylene blue on them showed marked improvement reaching as much as 80 mg of methylene blue on 1 g of the resin. On the other hand, in the case of bromophenol blue, its amount of adsorption appeared 250 mg per 1 g of the resin. The TGA under $N_2$ atmosphere indicated that the resin formed in molar ratio of 1 : 3 : 8 (PPD : MAP : F) showed the best heat-resistant property among others. About 40 % weight loss was observed for this resin at 900$^{\circ}$ with heating rate of 2$^{\circ}$ per minute.