• Korean Journal of Microbiology
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• v.51 no.1
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• pp.7-13
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• 2015

Hydrotrope-combined copper (HCC) is a copper ($Cu^{2+}$)-based algicide, which is combined with a hydrotrope that keeps copper ion in solution to improve performance. This study assessed the growth inhibition effect of HCC against Microcystis aeruginosa which is one of the most common toxic cyanobacterium in eutrophic freshwater environment. Various HCC doses, ranging from 5.5 to $550{\mu}g/L$ as $Cu^{2+}$, were applied to either BG-11 or 1/4 diluted medium with low- or high-inoculum density of M. aeruginosa. Growth inhibition was monitored based on a decrease in chlorophyll-a content in culture medium during the incubation. Results showed that HCC significantly inhibited the growth of M. aeruginosa in a dose-dependent manner. In case of 1/4 diluted BG-11 medium, HCC dose as low as $5.5{\mu}g$ $Cu^{2+}/L$ completely inhibited the production of chlorophyll-a by M. aeruginosa. It was found that HCC did not induce any significant release of microcystin-LR from M. aeruginosa. Acute toxicity of HCC was tested using Daphnia magna, and the 24-h $EC_{50}$ value was 0.30 mg/L as $Cu^{2+}$ which was much higher than the actual inhibition dose. Ames test was performed using Salmonella enterica serovar Typhimurium TA100, and HCC showed no increase in the number of revertant colonies. The result suggested that HCC does not have any mutagenic potential in the aquatic environment. In addition, no genotoxic effect of HCC was also confirmed based on the SOS ChromoTest using Escherichia coli PQ37. Therefore, HCC could be used as a relatively safe and effective pre- and post-treatment agent to control hazardous algal blooming in aquatic environments.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.203-210
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• 2006

This experiment was conducted to determine the Effect of soybean oil, dried palm oil powder and monoglyceride supplementation on growth performance and serum lipid changes in weaned pigs. One hundred twenty five cross-bred pigs((Y×L)×D, 6.00±0.79kg average initial BW) were used in a 21 d growth trial. Dietary treatments included SOY(containing 5% soybean oil), PALM(containing 5.5% dried palm oil powder) and SOPM0, 12.5 and 25(containing 2.5% soybean oil and 2.7% dried palm oil powder containing 0%, 12.5% and 25.0% monoglyceride, respectively). For the whole period, ADFI was increased in dried palm oil powder containing monoglyceride and PALM treatments compared with SOY and SOPM0 treatment(P<0.05). ADG and G/F were not affected by treatments. Digestibility of fat was higher(P<0.05) for pigs fed SOY diet than fed other diets. SOPM diets containing monoglyceride showed increased fat digestibility compared with PALM diet(P<0.05). SOPM12.5 and SOPM25 treatments were no difference with SOY treatment. However, there were no significant differences in digestibilities of DM, N and DE(P>0.05). Backfat thicknesses were not significantly different among treatments. Pigs fed SOY diet was decreased in serum total cholesterol, HDL-cholesterol, total lipid and was increased in free fatty acid than those fed other diet. Also, triglyceride concentration in serum was increased in PALM treatment compared with SOPM treatment(P=0.06). In conclusion, feeding soybean oil in weaned pigs showed higher fat digestibility and lower cholesterol and triglyceride concentration in serum than feeding only dried palm oil powder. Also, pigs fed monoglyceride were improved fat digestibility compared with those fed dried palm oil powder only.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.5
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• pp.394-406
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• 1991

It was proved that cold tolerance of rice plants at the young microspore stage was affected by water temperature and nitrogen application from the spikelet differentiation stage to the young microspore stage, and this mechanism could be explained in the point of view of pollen developmental physiology. The cold tolerance of rice plants at the young microspore stage was severely affected by water temperature (Previous water temperature) and nitrogen application(Previous nitrogen application) from the spikelet differentiation stage to the spikelet differentiation stage. Although the duration is only 10 days or so from the spikelet differentiation stage to the young microspore stage, these days are very important period to confirm the cold tolerance of rice plants at the young microspore stage. The higher previous water temperature up to $25^{\circ}C$ and the deeper previous water depth up to 10cm caused the more cold tolerance of rice plants. Water irrigation of 10cm before the cretical stage showed lower cool injury than that of water irrigation of 20cm during the critical stage. The preventive effect of cool injury by combined treatment of the deep water irrigation before and during the critical stage was not additive but synergistic. The cold tolerance of rice plants grown in previous heavy nitrogen level was rapidly decreased when nitrogen content of leaf blade at the young microspore stage was excessive over the critical nitrogen level. Nitrogen content of leaf blade at the changing point of cold tolerance was estimated as about 3.5% for Japonica cultivars and about 2.5% for Indica x Japonica cultuvars. It is considered that these critical nitrogen contents of leaf blade can be used as a index of the safe critical nitrogen level for the preventive practices to cool injury. It was summarized that increase of engorged pollens per anther by high previous water temperature resulted from the increase of number of differentiated microspores per anther, otherwise, the increase of engorged pollens by the decrease of previous nitrogen level was caused by the decrease of the number of aborted microspores per anther.

• Korean Journal of Environmental Agriculture
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• v.19 no.1
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• pp.32-37
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• 2000

Because the household garbage had high water contents, it is difficult to compost it without an additive. Therefore, this study was performed to investigate possibility of using the waste newspapers as a humidity conditioner for the household garbage composting. The maximum temperature was $66.0^{\circ}C$ in spring, $69.2^{\circ}C$ in summer, $60.9^{\circ}C$ in fall and $56.0^{\circ}C$ in winter for composting periods. The seasonal pH value reached around 8.5 after 1 week and then repeated fluctuation at the narrow range in spring and fall, while it was stabilized at the range of $8{\sim}9$ after increasing to 8.5 after 1 week in winter. The water content was reduced little in winter, while decreased significantly in the other seasons. The water content after 8 weeks was 22.2% in spring, 47.6% in summer, 25.5% in fall and 72.5% in winter. The mass was reduced rapidly during the first week of each season, but it did not show much decrease. The volume reduced after 8 weeks to 59%, 32%, 27%, and 34% in spring, summer, fall and winter respectively. Organic matter content decreased over the four seasons. Nitrogen contents were in the range of 0.7% to 2.2% during the four seasons. The contents of inorganic compounds based on dry matyter were in the range of $0.94{\sim}2.59%\;P_2O_5$, $1.23{\sim}1.87%\;CaO$, $0.37{\sim}0.46%\;MgO$, $0.55{\sim}1.98%\;K_2O$. Concentration of heavy metals(Hg, Cd, Pb, Cu, Cr, Zn, As) based on dry matter were less than the limiting value of the by-product compost.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.237-246
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• 2008

Filtration rates and fecal production of freshwater bivalve, Unio douglasiae on two kinds of hibernal diatom communities were measured simultaneously in a laboratory. One community is the Han River (HAN), which dominated by Asterionella Formosa. Stephanodiscus hantzschii (ca. 98% of total phytoplankton). The other community is the Ilgam Lake (IL), which dominated by Synedra ulna, Scenedesmus sp. Microcystis aeruginosa (ca. 82%). The HAN water has higher concentrations of nutrient (TN and TP) and chlorophyll $\alpha$ (Chl-$\alpha$), lower turbidity and conductivity than the IL water. Water sampling for the feeding experiment was conducted in the same day (Jan 15, 2008) and similar time (AM 10:00 for HAN, AM 11:00 for IL). Mussels with the similar size ($0.0{\pm}0.5\;cm$) were collected from the Gunsan and Okgu district (Jeonbuk), and starved in a laboratory for 2 days before the experiment. The experiment comprised CON (no addition of mussel), LOW (addition of mussel at 0.3 indiv. $L^{-1}$), MID (1.0 indiv. $L^{-1}$) and HIGH (2.0 indiv. $L^{-1}$), respectively. With the increment of mussel density and time, the concentration of Chl-$\alpha$ in two diatom communities were clearly decreased; Chl-$\alpha$ of HAN gradually decreased after 1 hour of mussel treatment, while that of IL decreased as soon as mussel introduction. In 7 hours of treatment, the former was removed finally up to about 90% of control, while the later was remained as about 50%. Under the presence of mussel, total phytoplankton density was shifted as the similar patterns to that of Chl-$\alpha$ (r=0.705, P<0.0001), however, there showed the drastic differences following a species. Based on the concentration of Chl-$\alpha$, filtration rate of U. douglasiae averaged 0.266 $L\;g^{-1}\;h^{-1}$ (0.115 to 0.442) on HAN and $0.577\;L\;g^{-1}\;h^{-1}$ (0.146 to 1.428) on IL water, respectively. There were no differences in feces production among the mussel density in the HAH water (ANOVA, P>0.5), while in IL water, including lots of seston, the HIGH mussel produced the higher fecal materials, over one hundred times of LOW. These results suggest that freshwater bivalve Unio douglasiae have the alternative potential, as a filter-feeder of seston in turbid lake, and a biological controller of diatom bloom in cold stream.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.103-108
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• 2010

To obtain the best yield of the beneficial ingredients in green tea, such as catechins, green tea powder is most often prepared by ethyl alcohol extraction. However, the taste, cost and composition of ethyl alcohol extract is different from aqueous spray-dried green tea extract (aq-GTE). Specifically, aq-GTE has a better flavor, lower production costs and higher purity when compared to ethyl alcohol extract. In this study, we elucidated the effect of aq-GTE on diet-induced obesity in male C57BL/6J mice following dose-dependent oral administration of aq-GTE. After eight weeks, the body weight was reduced by 13-17% in mice fed 200 mg/kg bw aq-GTE ($12.468{\pm}0.45\;g$; p<0.05) and 20-25% in mice fed 400 mg/kg bw aq-GTE ($11.259{\pm}0.61\;g$; p<0.05) when compared with the high-fat diet (HFD) control group mice ($14.714{\pm}0.95\;g$; p<0.05). The correlation between epididymal fat accumulation and body weight also decreased by approximately 26.6% (p<0.05) in mice fed a HFD with aq-GTE 400 mg/kg bw. Finally, serum parameters such as the triglyceride, glucose and cholesterol levels in the HFD groups were reduced by the aq-GTE 400 mg/kg bw diet. Analysis on glutamic-pyruvic transaminase, blood urea nitrogen and development of hepatic steatosis revealed no histologic evidence of hepatotoxicity in HFD mice fed aq-GTE. Overall, our results imply that aq-GTE is able to regulate body weight and fat accumulation in mice.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.56-62
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• 2010

Quality characteristics such as alcohol, acid, and sugar contents of takju brewing mashes prepared using several yeasts were investigated during 12-days of fermentation. Among the yeasts examined, S. cerevisiae led to the highest level of ethanol (10.2-13.4%) and total minor alcohols (0.729-0.831 mg/mL). Regardless of the yeasts used, the acidity showed drastic changes (pH from 3.4-4.2 down to 2.4-2.7) during the first 2 days, and displayed negligible changes from day 4. The total acid contents rapidly increased to the first 4 days of fermentation and leveled off from 4 to the end of fermentation period. The common organic acid components were lactic, succinic and acetic acids. The total and reducing sugar contents varied depending on the yeasts used, with mashes prepared using S. coreanus and S. rouxii producing the maximum total sugar contents (5.43-5.5%) at the end of fermentation. The reducing sugar showed its maximum (7.53-14.89%) at day 2, after which it decreased to its minimum levels (3.04-4.52%). The common free sugar components were glucose and fructose, while S. ellipsoideus led to a higher free sugar level (0.35-5.29%).

• Development and Reproduction
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• v.5 no.1
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• pp.73-79
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• 2001

Recently many studies have reported that total and bioavailable androgens reduced in male and female athletes and that physical exercise reduces the body weight and increases the reproductive abnormalities such as oligomenorrhea, anovulation, inadequate luteal phase, and delayed puberty in women by the inhibition of the hypothalamic-pituitary-gonadal (HPG) axis . In addition, high mileage endurance 겨nning, psychological stress, and military endurance training in men also reduce the secretion of reproductive hormones. To investigate the efffcts of physical endurance exercise on the secretion of reproductive hormones in men, androgenic hormones from adrenal glands and testis were measured in serum by the conventional radioimmunoassays after long-term (more than3 months), short-term (1 week), and acute (1${sim}$2 hours) physical exercises. Androgenic hormones from adrenal glands and testis such as total testosterone (TT), free testosterone (fT), dehydroepiandrosterone (DHEA), and androstenedione (A) decreased after thesestrenuous endurance trainings, whereas ACTH, cortisol, and dehydroepiandrosterone sulfetes (DHEAS) increased. Conadotropins (LH and FSH) were not idluenced by the physical exercises. Based upon the present results, we assume that the decrease in adrenal and testicular androgens by physical endurance exercises might be associated with the reproductive abnormalities in athletes by unknown factor(s) in addition to the HPG axis disturbance.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.767-776
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• 2003

An experiment was conducted to investigate the effects of dietary herbal product(Miracle$^{\circledR}$) supplementation on the performance, nutrient digestibility, fecal microflora and blood parameters in pigs. Forty eight cross bred(Y${\times}$L${\times}$D) weanling pigs (average initial body weight 7.84kg${\pm}$0.17, 28 d old) were used in 35 d feeding trial. Pigs were allotted to 16 raised floor cages(W 35.5cm${\times}$L45cm${\times}$H 55cm). Each treatment had four replications of 3 pigs each. Treatments were: control (T1), CTC 100ppm (T2), Miracle$^{\circledR}$ 0.15% (T3) and CTC 100ppm + Miracle$^{\circledR}$ 0.15% (T4). The herbal product supplementation(T3) tended to improve the weight gain, feed intake, feed/gain but there were no significant differences among treatments. Nutrient digestibility was significantly(P〈0.05) affected by dietary treatments. The pigs fed T3 diet showed the lowest digestibility of DM, crude protein, NFE, P, and amino acids among treatments. Serum cholesterol level of pigs fed T3 diet was lowest and significantly(P〈0.05) lower than those fed antibiotic supplemented diet(T2). Triglyceride and HDL level of the pigs fed T3 diet were also lower than those of others but the differences were not significant. The level of serum IgG was significantly(P〈0.05) different among treatments. The level of serum IgG was highest in T4, followed by T1, T2 and T3. Serum AST(Aspartate aminotransferase) level of the control(T1) was lower than other treatments. Levels of serum total protein, albumin and ALT(Alanine aminotransferase) were not significantly different among treatments. The colony forming units (CFU) of Lactobacillus, Cl. perfringens and E.coli in feces were not significantly different among treatments but those of Cl. perfringens of T2 (CTC 100ppm) showed the lowest count at both 3rd and 5th wk. It is concluded that herbal product Miracle$^{\circledR}$ does not significantly affect growth performance of weanling pigs but it influenced the digestibility, serum IgG, cholesterol and AST level. The combination of the herbal product Miracle$^{\circledR}$ with antibiotic(CTC) showed no synergistic effects.

• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.106-110
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• 2008

This study was designed to evaluate the single dose toxicity and the protective effect of water extract of Cordyceps militaris grown upon Protaetia dreujtarsis (CMPD extract) on liver damage on carbon tetrachloride ($CCl_4$)- induced acute hepatotoxicity in Sprague-Dawley (SD) rats. The CMPD extract was once administered orally to both sexes of rats at dose of 2,000, 1,000 and 500 mg/kg body weight, the recommended maximum limit dose for acute toxicity. Neither significant toxic signs nor death was observed during the observation period. These results indicate that $LD_{50}$(lethal dose of 50%) of CMPD extract is greater than 2,000 mg/kg body weight in SD rats. To investigate also the effect of hepatoprotection of CMPD extract, SD rats were orally treated with CMPD extract (50, 25 and 12.5 mg/kg body weight) or silymarin (25 mg/kg body weight) before and after administration of $CCl_4$ (2 mL/kg body weight, 20% $CCl_4$ in olive oil). Treatment with CMPD extract or silymarin could decrease the GPT (glutamic-pyruvic transaminase) and GOT (glutamic-oxaloacetic transaminase) levels in serum when compared with $CCl_4$-treated group. Therefore, the results of this study show that CMPD extract can be proposed to protect the liver against $CCl_4$-induced hepatic damage in rats.