• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.2
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• pp.124-128
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• 2016

The objective of this research was to determine the effects of harvesting frequency and fertilization levels on botanical composition, dry matter yield, and forage feed compositions of Alpine grassland at 800 m altitude. This research lasted for three years at National Alpine Agricultural Research Institute in Pyeongchang with two harvesting frequency schedules (two and three times annually) and two levels of fertilizer application (conventional level of fertilizer at 280-200-240 kg/ha and a lower level of fertilizer at 200-200-200 kg/ha for N, $P_2O_5$, and $K_2O$). Mixture combinations with seeding rate (kg/ha) were as follows: Orchardgrass 18, Tall fescue 9, Timothy 8, Kentucky bluegrass 3, and Ladino Clover 2. The gramineae ratio ranged from 93.2 to 95.3%. Therefore, gramineae forage was considered as the dominant plant in this experiment. No significant (p>0.05) difference was observed in forage dry matter yield between the two harvesting frequency treatments (two times at 9.8 ton/ha and three times at 8.6 ton/ha). However, forage dry matter yield in the two times of harvesting frequency tended to be greater than that in the three times of harvesting frequency. Significantly (p<0.05) higher forage dry matter yield in the standard fertilization level group than the lower fertilization level group (9.8 ton/ha vs. 8.7 ton/ha) was observed. However, there was no significant (p>0.05) difference in forage crude protein concentration between the two harvesting frequency treatment groups, although the concentration in the group with three times of harvesting frequency tended to be higher. In contrast, crude fiber concentration in the group with two times of harvesting frequency tended to be higher, although the difference was not statistically significant (p>0.05). Crude protein, ether extract, crude fiber, and organic matter concentrations were not significantly (p>0.05) different between the two groups with different fertilization levels. Based on these results, it was concluded that the group with two times of harvesting frequency with conventional fertilization level might be proper for obtaining better forage productivity for Alpine grassland at 800 m altitude.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.10
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• pp.649-657
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• 2017

A rupture in a high-pressure pipe causes the fluid in the pipe to be discharged in the atmosphere at a high speed resulting in a supersonic jet that generates the compressible flow. This supersonic jet may display complicated and unsteady behavior in general. In this study, Computational Fluid Dynamics (CFD) analysis was performed to investigate the compressible flow generated by a supersonic jet ejected from a high-pressure pipe. A Shear Stress Transport (SST) turbulence model was selected to analyze the unsteady nature of the flow, which depends upon the various gases as well as the diameter of the pipe. In the CFD analysis, the basic boundary conditions were assumed to be as follows: pipe of diameter 10 cm, jet pressure ratio of 5, and an inlet gas temperature of 300 K. During the analysis, the behavior of the shockwave generated by a supersonic jet was observed and it was found that the blast wave was generated indirectly. The pressure wave characteristics of hydrogen gas, which possesses the smallest molecular mass, showed the shortest distance to the safety zone. There were no significant difference observed for nitrogen gas, air, and oxygen gas, which have similar molecular mass. In addition, an increase in the diameter of the pipe resulted in the ejected impact caused by the increased flow rate to become larger and the zone of jet influence to extend further.

• Journal of radiological science and technology
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• v.25 no.1
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• pp.63-71
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• 2002

The aim of this study Is to develop a simple and fast method which computes in-vivo doses from transmission doses measured doting patient treatment using an ionization chamber. Energy fluence and the dose that reach the chamber positioned behind the patient is modified by three factors: patient attenuation, inverse square attenuation. and scattering. We adopted a straightforward empirical approach using a phantom transmission factor (PTF) which accounts for the contribution from all three factors. It was done as follows. First of all, the phantom transmission factor was measured as a simple ratio of the chamber reading measured with and without a homogeneous phantom in the radiation beam according to various field sizes($r_p$), phantom to chamber distance($d_g$) and phantom thickness($T_p$). Secondly, we used the concept of effective field to the cases with inhomogeneous phantom (patients) and irregular fields. The effective field size is calculated by finding the field size that produces the same value of PTF to that for the irregular field and/or inhomogeneous phantom. The hypothesis is that the presence of inhomogeneity and irregular field can be accommodated to a certain extent by altering the field size. Thirdly, the center dose at the prescription depth can be computed using the new TMR($r_{p,eff}$) and Sp($r_{p,eff}$) from the effective field size. After that, when TMR(d, $r_{p,eff}$) and SP($r_{p,eff}$) are acquired. the tumor dose is as follows. $$D_{center}=D_t/PTF(d_g,\;T_p){\times}(\frac{SCD}{SAD})^2{\times}BSF(r_o){\times}S_p(r_{p,eff}){\times}TMR(d,\;r_{p,eff})$$ To make certain the accuracy of this method, we checked the accuracy for the following four cases; in cases of regular or irregular field size, inhomogeneous material included, any errors made and clinical situation. The errors were within 2.3% for regular field size, 3.0% irregular field size, 2.4% when inhomogeneous material was included in the phantom, 3.8% for 6 MV when the error was made purposely, 4.7% for 10 MV and 1.8% for the measurement of a patient in clinic. It is considered that this methode can make the quality control for dose at the time of radiation therapy because it is non-invasive that makes possible to measure the doses whenever a patient is given a therapy as well as eliminates the problem for entrance or exit dose measurement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.9
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• pp.1137-1142
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• 2017

This study examined the effects of apios (Apios americana Medikus) supplementation on visceral obesity in high-fat diet-induced obese mice. C57BL/6N mice were fed a high-fat diet (40% calories from fat) with or without apios powder (10%, w/w) for 12 weeks. At the end of the experiment, apios supplementation reduced visceral fat mass significantly by 14.3% compared to the control group. Apios decreased significantly the atherogenic index, serum leptin level, hepatic lipid (free fatty acid and triglyceride) content, and lipid droplets, whereas it increased the serum high density lipoprotein-cholesterol/total cholesterol ratio. Hepatic lipogenic gene expression of peroxisome proliferator activated receptor gamma, fatty acid synthase, and diacylglycerol O-acyltransferase 2 was down-regulated by apios supplementation. These results suggest that apios is a healthy food for preventing high-fat diet-induced visceral obesity and fatty liver.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.6
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• pp.886-897
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• 2014

The aim of the present study was to get a total physical and chemical characterization and comparison of the principal components in Bangladeshi buffalo (B), Holstein cross (HX), Indigenous cattle (IC) and Red Chittagong Cattle (RCC) milk. Protein and casein (CN) composition and type, casein micellar size (CMS), naturally occurring peptides, free amino acids, fat, milk fat globule size (MFGS), fatty acid composition, carbohydrates, total and individual minerals were analyzed. These components are related to technological and nutritional properties of milk. Consequently, they are important for the dairy industry and in the animal feeding and breeding strategies. Considerable variation in most of the principal components of milk were observed among the animals. The milk of RCC and IC contained higher protein, CN, ${\beta}$-CN, whey protein, lactose, total mineral and P. They were more or less similar in most of the all other components. The B milk was found higher in CN number, in the content of ${\alpha}_{s2}-$, ${\kappa}$-CN and ${\beta}$-lactalbumin, free amino acids, unsaturated fatty acids, Ca and Ca:P. The B milk was also lower in ${\beta}$-lactoglobulin content and had the largest CMS and MFGS. Proportion of CN to whey protein was lower in HX milk and this milk was found higher in ${\beta}$-lactoglobulin and naturally occuring peptides. Considering the results obtained including the ratio of ${\alpha}_{s1}-$, ${\alpha}_{s2}-$, ${\beta}$- and ${\kappa}$-CN, B and RCC milk showed best data both from nutritional and technological aspects.

• Osteoporosis and Sarcopenia
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• v.2 no.4
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• pp.228-237
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• 2016

Objective: There has been no prospective study that examined intramuscular injection of high-dose vitamin D in Korean adults. The aim of this study was to assess the efficacy and safety of high-dose vitamin $D_3$ after intramuscular injection in Korean adults with vitamin D deficiency. Method: This study was a 24-week, prospective, multicenter, randomized, double-blind, placebo-controlled trial. A total of 84 subjects ${\geq}19$ and <65 years of age were randomly allocated to either the vitamin $D_3$ or placebo group in a 2:1 ratio. After randomization, a single injection of plain vitamin $D_3$ 200,000 IU or placebo was intramuscularly administered. If serum 25-hydroxyvitamin D (25[OH]D) concentrations were <30 ng/mLon week 12 or thereafter, a repeat injection was administered. Results: After a single intramuscular injection of vitamin $D_3$ to adults with vitamin D deficiency, the proportion of subjects with serum 25(OH)D concentrations ${\geq}30ng/mL$ within 12 weeks was 46.4% in the vitamin $D_3$ group and 3.6% in the placebo group (p<0.0001). The proportion of subjects with serum 25(OH)D concentrations ${\geq}30ng/mL$ within 24 weeks was 73.2% in the vitamin $D_3$ group and 3.6% in the placebo group (p<0.0001). Mean change in serum 25(OH)D concentrations at weeks 12 and 24 after vitamin $D_3$ injection was $12.8{\pm}8.1$ and $21.5{\pm}8.1ng/mL$, respectively, in the vitamin $D_3$ group, with no significant changes in the placebo group. Serum parathyroid hormone concentrations showed a significant decrease in the vitamin $D_3$ group but no change in the placebo group. Conclusion: Intramuscular injection of vitamin $D_3$ 200,000 IU was superior to placebo in terms of its impact on serum 25(OH)D concentrations, and is considered to be safe and effective in Korean adults with vitamin D deficiency.

• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.53-73
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• 2002

It has been reported that degranulation of mast cells in rats, rabbits and dog was observed after dosing xylazine hydrochloride(Xh) which has been widely used as sedative, analgesic and muscular relaxant. Therefore, this experiment was conducted to examine the relations between Xh and histamine release and to identify the action of ${\alpha}$-adrenoceptors which exists on the suface of mast cells. 1. The content of histamine within serum was measured with HPLC by performing the O-phthalaldehyde(OPA) fluorescent derivation. The pretreatment method had a little modification from the conventional method. The pretreament was carried out in the following method. 0.2$m\ell$ of serum and 1$m\ell$ of butanol were added to mixed together and then the liquid was centrifugally separated at 4$^{\circ}C$ and 2,000 rpm for 3 minutes. 0.4$m\ell$ of 0.1N HCl and 1.6$m\ell$ of heptane were added to 0.8$m\ell$ of supernatant taken from the liquid, and they were mixed together. This mixture was also centrifugally separated at 4$^{\circ}C$ and 2,000 rpm for 5 minutes. The supernatant was thrown away and the OPA fluorescent derivation was carried out with 0.2$m\ell$ of the lower liquid then, 5 minutes after mixing 400${\mu}\ell$ of 0.1N HCl, 120${\mu}\ell$ of 1N NaOH and 40${\mu}\ell$ of 0.1% OPA in the 0.2$m\ell$ of the lower liquid,120${\mu}\ell$ of 3.57N H$_3$PO$_4$ was added to the mixed liquid, and the liquid, was mixed again and syringe-filtered. Then, the measurement was done with HPLC in the 30 : 70(ν/ν) ratio of 0.004M KH$_2$PO$_4$: CH$_3$CN, flow rate of 1.0$m\ell$/min., and a wavelength of λex= 350nm and λem=444nm at the column temperature of 27$^{\circ}C$, using the fluorescence detector. 2. The content of histamine in each laboratory animal appeared to be higher in such an order as rabbit, rat, guinea pig, dog, Korean indigenous goat, swine, Korean indigenous cattle, Holstein, and mouse, of which the individual mean values${\pm}$standard deviation were 2.0668 ${\pm}$ 0.6049. 0.4999 ${\pm}$ 0.2278, 0.4241 ${\pm}$ 0.1974, 0.1054 ${\pm}$ 0.0556, 0.1028 ${\pm}$ 0.0276, 0.0972 ${\pm}$ 0.0513, 0.0872 ${\pm}$ 0.0373, 0.0717 ${\pm}$ 0.0379, and 0.0706 ${\pm}$ 0.0366, respectively. 3. The content of histamine was measured at the moments of 15-, 30-, 60-, 120-minutes after inoamuscular injection of 20mg/100kg Xh into two to 4 years old Holstein weighing 600∼700kg. The result showed that there was a significant increase at the times of 30- and 90-minutes after injection(p<0.05). 4. Intramuscular injection of 3mg/10kg Xh was given to crossbred pug dogs weighing 2.5∼4.3kg. The content of histamine was measured at the times of 30-, 60-, 90- and 120-minutes after injection. The result revealed that there was a significant increase at the times of 60-and 90-minutes after injection(p<0.05). 5. Intramuscular injection of 10mg/$m\ell$∼25mg/$m\ell$ Xh in concentration of 0.1$m\ell$ was applied to Korean indigenous goat over 5 months old. Then, the content of histamine was measured at the times of 15-, 30-, 60- and 90-minutes after injection. A significant increase was shown at the times of 30- and 60-minutes after injection(p<0.05). 6. The content of histamine was measured at the moments of 30- and 60-minutes after intramuscular injection of 0.1-0.2$m\ell$ Xh (20mg/$m\ell$) into male rabbits weighting 2.5-4kg. A significant increase was found at the moment of 60 minutes after injection(p<0.001). 7. After administering Xh to the mast cell taken from the abdominal cavity of mouse, the content of histamine was measured. The result showed that the higher the concentration, the more significantly the content of histamine was increased(p<0.05). 8. Compound 48/80 was administered in concentration of 5$\mu\textrm{g}$/$m\ell$ and 10$\mu\textrm{g}$/$m\ell$ to the mast cell picked from the abdominal cavity of mouse. The result showed that there was a significant increase in the content of histamine in case of the concentration of 10$\mu\textrm{g}$/$m\ell$(p<0.05). It was found to be about 10,000 to 500,000 times stronger than the Xh. 9. After premedication of 1mg/kg of yohimbine hydrochloride as ${\alpha}$$_2$-adrenergic antagonist to rabbits, the Xh was administered to them. The result was that the value of histamine within serum was decreased significantly(p<0.001). 10. After premeditation of 1mg/kg of prazosin hydrochloride as ${\alpha}$$_1$-adrenergic antagonist to rabbits, the Xh was administered to them. It was found that the value of histamine within serum was decreased significantly(p<0.005). 11, Prazosin hydrochloride and yohimbine hydrochloride as ${\alpha}$$_1$-adrenergic antagonist, respectively, and ${\alpha}$$_2$-adrenergic antagonist were administerd. In this case, the value of histamine within serum was decreased significantly(p<0.0001). As the results, when the Xh is administered to various kinds of animals, the amount of histamine release within serum is increased. In view of the results so far achieved, it is concluded that Xh acted on both a$_1$-adrenoreceptor and ${\alpha}$$_2$-adrenoreceptor induces the degranulation of mast cell.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.366-373
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• 2000

Toxin production and low digestibility of cyanobacteria are known to cause low exploitability of cyanobacteria by zooplankton. In this study, we compared relative tolerance and compatibility of zooplankton taxa in eight eutrophic lakes, exposed to frequent cyanobacterial blooms, uring the summer season of 1999. Microcystis, Anabaena, Oscillatoria and Phormidium were common cyanobacteria in all lakes. with relatively lower $NO_3-N$ concentration (<0.2 mgN/l) and TN/TP ratio (<20), compared with other lakes where colonial cyanobacteria dominated. Rotifers were dominant zooplankton in most lakes, and among them, Keratella, Polyarthra and Hexathra were common. The laboratory feeding experiment showed that relative copepods that greatly decreased (90%) after 4 day when cyanobacteria were used as the food source of zooplankton, while rotifers gradually increased with the change of dominant taxa from Keratella through Pompholyx to Monostyla. These results suggest that rotifers may be capable of coexisting with cyanobacteria by exploiting them for the food source.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.626-634
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• 2012

The purpose of this study was to investigate the potential of persimmon vinegar as a functional beverage by analyzing the effects of persimmon vinegar ingestion on the energy substrate during endurance exercise. The healthy male adolescents (n=8) drunk persimmon vinegar ingested trial (PSV) or purified water ingested trial as the control trial (CON) 1 h prior to the exercise with the 60% of maximal oxygen uptake ($\dot{V}O_{2max}$) for 1 h. The exercise intensity was increased to the 80% of $\dot{V}O_{2max}$ and remained until exhaustion. And, the physiological variables, blood components, and amounts of energy oxidation were analyzed. There was no significant difference between trials in physiological variables, and the heart rates after exhaustion were higher in PSV compared to CON. There was no significant difference between trials in blood glucose level, while the blood lactic acids decreased significantly in PSV 30 and 60 minutes after onset of exercise. The free fatty acids concentration increased significantly in PSV from 15 minutes to 60 minutes after onset of exercise. The carbohydrate oxidation decreased significantly in PSV from 45 minutes after exercise and, on the contrary, the fatty acids oxidation increased significantly for the same period. And, fatty acids oxidation was higher in PSV compared to CON even after exhaustion. The respiratory exchange ratio was lower significantly in PSV compared to CON from 30 minutes to 60 minutes after exercise, whereas lower in CON after total exhaustion. The exercise time to exhaustion was 41% longer in PSV compared to CON. These results showed that the persimmon vinegar increase the level of lipids metabolism and decrease sense of fatigue by inhibiting carbohydrate oxidation during moderate intensity exercise, suggesting the possibility of using of persimmon vinegar as exercise functional beverage when ingested 1 h prior to the endurance exercise performance.

• Journal of Nutrition and Health
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• v.45 no.1
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• pp.20-29
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• 2012

Metabolic syndrome (MetS) has become a global epidemic. In particular, it is known that there is a dramatic increase in the prevalence of MetS among women during the postmenopausal period. Recently, accumulating studies have suggested that vitamin D deficiency may be inversely associated with the risk factors regarding MetS. However, evidence from postmenopausal women is limited. In this study, we examined the association between the serum 25-hydroxyvitamin D [25(OH)D] and the MetS in Korean adult women aged 20-69 years (n = 2,618) by using the 2007-2008 Korean National Health and Nutrition Examination Survey data. The geometric mean of plasma 25(OH)D were $17.16{\pm}6.28\;ng$/mL and $20.20{\pm}7.69\;ng$/mL for premenopausal and postmenopausal women, respectively. The percentages of vitamin D deficiency [25(OH)D < 12 ng/mL] were 22.5% and 14.4%, respectively. MetS was more prevalent in postmenopausal women (43.0%) compared with premenopausal women (11.2%). When serum concentrations of 25(OH)D were categorized in quintiles, there was no relationship in the prevalence of MetS in both premonopausal and postmenopausal women. However, in premenopausal women, compared with the lowest 25(OH)D quintile, the odds ratio for hypertriglyceridemia in the highest quintile was 0.57 (95% CI 0.34-0.95, $P_{trend}$ = 0.041) and for low serum HDL cholesterol 0.60 (95% CI 0.42-0.85, $P_{trend}$ = 0.014) after adjusting for all potential confounders. On the other hand, we observed the tendency of an inverse relationship for 25(OH)D regarding low serum HDL cholesterol (OR 0.78, 95% CI 0.50-1.22, $P_{trend}$ = 0.029) and a direct relationship with abdominal obesity (OR 1.94, 95% CI 1.01, 3.74, $P_{trend}$ = 0.049) in postmenopausal women. Further studies are needed to confirm these findings in other research settings.