• Journal of Soil and Groundwater Environment
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• v.11 no.3
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• pp.43-51
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• 2006

Generally abandoned mine soils have serious problems for introducing vegetation such as nutrient deficiency, poor physical properties, and phytotoxicity due to high levels of heavy metals. It is required to improve soil amenity for revegetation. One of its strategies is using organic materials such as compost manure and sludge. The pot experiments was conducted to evaluate the effects of pig manure and municipal sewage sludge on revegetation of mining area soil surface with Artemisia princeps and Zoysia japonica. Application rate of pig manure and municipal sewage sludge was $75{\sim}225$ Mg/ha and $150{\sim}450$ Mg/ha, respectively. The results showed that the application of manure and sludge increased organic matter about two-fold and total nitrogen contents about five-fold of mine soil and improved the growth of plants in all treatments compared to the control. The result of plant tissue analysis showed that both plants accumulate Cd, Cu and Zn in root tissue rather than shoot tissues. Increased sludge application reduced Zn accumulation in both plant tissue. Sequential extraction results indicated that addition of soil amendment induced increment of organically bound fractions of Cu and Zn. Organically bound fraction of Zn was significantly increased from 7.84% to 13.58% in Artemisia princeps planted soil and from 7.84% to 14.16% in Zoysia japonica planted soil, thereby bioavailability of heavy metals was reduced. The results suggested that application of organic materials to mine soil can reduce phytotoxicity of heavy metals and be helpful in introducing successful revegetation.

• Korean Journal of Poultry Science
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• v.16 no.3
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• pp.149-156
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• 1989

Two broiler experiments were carried out to determine whether supplementation of zeolite in the diet would affect broiler performance and economical efficiency. Day old male broiler chickens of Abor Acres strain were used. In the first experiment,60 birds were distributed into f groups of 10 birds each. Three groups of chickens were randomly placed on one of the following single-stage (0-6wks) experimental diets； control diet (non-supplemented) or 2% zeolite supplemented diet (supplemented to the control). In the second experiment,216 birds were distributed into 24 groups of 9 birds each. Eight groups of chickens were randomly placed on one of the 3 two-stage diet (starter；0-4wks, finisher；5-7wks)；control diet ($T_1$ , non-supplemented), 2% zeolite diet ($T_2$：isocaloric and isonitrogenous as $T_1$ ) and 2% zeolite supplemented diet ($T_3$, supplemented to the control). Birds were housed in the batteries, and feeds and water were fed ad libitum. The results of Experiment 1 showed that birds fed control diet were heavier than those fed 2% zeolite supplemented diet up to 4th wks of age. However, birds fed the latter grew more at 5th and 6th wk. Overall weight gain, feed intake and feed efficiency were not significantly different. The results of Experiment 2 showed that there were no significant differences in weight gains, feed intakes and feed efficiencies among treatments during starter, finisher to overall period. The moisture levels in excreta of the birds were significantly (P＜0.01) less when zeolite was included in the diets and those in excreta significantly (P ＜ 0.01) increased as the ambient temperature increased. Economical efficiency expressed in fed cost (won) required per kg weight gin were 346.55 (T$_3$),348.34 ($T_1$ ) and 359.85 ($T_2$).

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.141-148
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• 2002

Two experiments were conducted to investigate the effects of supplemental feather digests on the growth of broiler chicks and taurine content in the broiler meat. In experiment 1, a total of 40 broiler chickens(Ros $s_{R}$) were assigned to four dietary treatments: control(T1), regular feather meal(FM) diet(R-FM,T2), NaOH treated FM diet(NaOH-FM,T3), HNO) treated FM diet($HNO_{3}$ -FM, T4). In experiment 2, a total of 70 broiler chickens were assigned to seven dietary treatments: T1 to t4(same as those of Exp. 1), modified $HNO_{3}$ treated FM diet(M- $HNO_{3}$-FM, T5), hair meal diet(HM, T6) and 0.22% cystine supplemented diet(CYS, T7). Feather meals and hair meal were supplemented at the level of 5% in the diet. In experiment 1 and 2, weight gain of chicks frd with R-FM or NaOH-FM tended to be higher than control or $HNO_{3}$ -FM. In experiment 2, weight gain of chicks frd with CYS was the highest followed by R-FM, M-HN $O_3$-FM, NaOH-FM, control, HM and $HNO_{3}$ -FM. In experiment 1, taurine content in breast muscle of chicks fed NaOH-FM was sogmofocamtly higher(P<0.05) than control. In experiment 2, taurine content in breast muscle of chicks fed NaOH-FM and CYS tended to be higher than other groups. Taurine content in leg muscle was significantly different among treatments as NaOH-FM and R-FM being highest followed by M- $HNO_{3}$-FM, CYS, control, $HNO_{3}$ -FM and HM. Taurine content in the liver(Exp. 1 and 2) and heart(Exp. 2) were not significantly affected by the supplemental feather digests. These results indicated that 5% NaOH-FM in the diet was effective in increasing taurine content in breast and leg muscle of broiler chicks.s.

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.119-128
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• 2003

The two experiments in this study compared litter nitrogen (N) contents after broiler chicks were raised for 42 days. Experiment I compared litter treated with aluminum sulfate (alum) [Al$_2$(SO$_4$)$_3$ㆍ14$H_2O$] (T$_1$) with nontreated litter (T$_2$) when the broiler chicks were fed the same levels of dietary protein (23% for 0∼3 weeks, 21% for 4∼6 weeks) Experiment 2 compared the alum treated litters of broiler chicks fed high protein diets (T$_3$) having 20.4% protein for 0∼3 weeks and 19.3% for 4∼6 weeks, with lower protein diets (T$_4$) having protein levels of 18.0% for 0∼3 weeks and 17.0% for 4 6 weeks. Each treatment had four replicate cages. As shown in Table 1, T$_1$ had a significantly (P<0.0l) lower pH and significantly (P<0.05) higher total N (TN), NH$_4$-N and inorganic N (IN) than T$_2$. T$_1$ and T$_2$ had similar moisture, organic carbon (OC), NO$_3$-N and organic N (ON). Alum treatment increased available N (AN) significantly (P<0.05) from 13.75$\pm$0.0l mg/g to 14.90$\pm$0.01 mg/g and predicted available N (PAN) significantly (P<0.05) from 15.00$\pm$0.0l to 16.50$\pm$0.02. The C : N ratios were 18.84$\pm$0.40 (T$_1$) and 19.46$\pm$0.10 (T$_2$) while the C : ON ratios were 28.49$\pm$1.15 (T$_1$) and 28.34$\pm$0.20 (T$_2$) although C : N ratios or C : ON ratios did not show any difference between T$_1$ and T$_2$. In Table 2, T$_3$ had significantly (P<0.05) higher moisture, TN, NH$_4$-N, ON and IN than T$_4$, while the pH, OC and NO$_3$-N were similar in both groups. The AN of T$_3$ increased significantly (P<0.05) from 10.99$\pm$0.0l mg/g to 12.98$\pm$0.03 mg/g, while the PAN increased significantly (P<0.05) from 12.39$\pm$0.10 mg/g (T$_4$) to 14.68$\pm$ 0.30 mg/g (T$_3$). The C : N ratios increased significantly (P<0.0l) from 20.07$\pm$0.20 (T$_3$) to 24.40$\pm$0.10 (T$_3$). The C : ON ratios also increased significantly (P<0.0l) from 28.99$\pm$1.15 (T$_3$) to 35.51$\pm$0.20 (T$_4$). These current research results show increased AN contents and PAN contents in alum treated litter or with increased CP levels regardless of alum treatment. However, none of the litters in this study could initially increase mineralization.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.95-100
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• 2002

Two experiments were conducted to investigate the effect of taurine supplementation on lipid metabolism in laying hens. In experiment 1, 19-wk-old laying hens were given one of four taurine supplemented diets (0 (control), 0.4, 0.8, and 1.2% taurine) fur 10 weeks. Abdominal fat weight was lower in the 1.2% diet by 29.2% compared to the control. Serum concentrations of triacylglycerol and HDL-cholesterol were not different among the treatments. However, seam concentration of total cholesterol was higher by 22.4% in the 1.2% diet compared to the control. Concentration of triacylglycerol or total cholesterol in the liver were decreased by 26.1% or 26.4% and 28.2% or 26.4%, respectively in the 0.8% and 1.2% diets compared to the control. The concentration of HDL-cholesterol in liver was also lower by 33.9% in the 1.2% diet compared to the control. In experiment 2, 81-wk-old laying hens were allocated to one of three taurine supplemented diets (0 (control), 1 and 2% taurine) fur 6 weeks. Abdominal fat weight was lower by 25% in 1% taurine supplementation compared to the control. Serum concentrations of triacylglycerol, total cholesterol and HDL-cholesterol of hens fed with 1% diet were not different from those of control group. However, sew concentrations of triacylglycerol and total cholesterol were lower by 44.0% and 19.8%, respectively in the 2% diet compared to the control. Furthermore, serum concentration of HDL -cholesterol in the 2% diet was higher by 75% compared to the control. Concentrations of triacylglycerol and total cholesterol in the liver in the 2% diet were decreased in the 1% diet by 36.8 and 23%, respectively, but increased by 78.4% and 70%, respectively, compared to the control. The concentration of HDL-cholesterol in the liver was not different between the 1% diet and the control, but higher by 62.8% in the 2% diet compared to the control. These results indicated that taurine supplementation decreased the fat storage in abdominal cavity, which was accompanied by the changes in triacylglycerol and cholesterol metabolisms of laying hens.

• Journal of Chest Surgery
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• v.23 no.3
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• pp.452-464
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• 1990

It is well known that extracellular Calcium plays a very important role in several steps of smooth muscle excitability and contractility, and there have been many concerns about factors influencing the distribution of extracellular Ca++ and the Ca++ flux through the cell membrane of the smooth muscle. Based on the assumption that Mg++ may also play an important role in the excitation and contraction processes of the smooth muscle by taking part in affecting Ca++ distribution and flux, many researches are being performed about the exact role of Mg++, especially in the vascular smooth muscle. But yet the effect of Mg++ in the smooth muscle activity is not clarified, and moreover the mechanism of Mg++ action is almost completely unknown. Present study attempted to clarify the effect of Mg++ on the excitability and contractility in the multiunit and unitary smooth muscle, and the mechanism concerned in it. The preparations used were the guinea-pig aortic strip as the experimental material of the multiunit smooth muscle and the rat uterine strip as the one of the unitary smooth muscle. The tissues were isolated from the sacrificed animal and were prepared for recording the isometric contraction. The effects of Mg++ and Ca++ were examined on the electrically driven or spontaneous contraction of the preparations. And the effects of these ions were also studied on the K+ or norepinephrine contracture. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% 02 and kept at 35oC. The results obtained were as follows: 1] Mg++ suppressed the phasic contraction induced by electrical field stimulation dose-dependently in the guinea-pig aortic strip, while the high concentration of Ca++ never recovered the decreased tension. These phenomena were not changed by the a - or b - adrenergic blocker. 2]Mg++ played the suppressing effect on the low concentration [20 and 40 mM] of K+-contracture in the aortic muscle, but the effect was not shown in the case of 100mM K+-contracture. 3] Mg++ also suppressed the contracture induced by norepinephrine in the aortic preparation. And the effect of Mg++ was most prominent in the contracture by the lowest [10 mM] concentration of norepinephrine. 4] In both the spontaneous and electrically driven contractions of the uterine strip, Mg++ decreased the amplitude of peak tension, and by the high concentration of Ca++ the amplitude of tension was recovered unlike the aortic muscle. 5] The frequency of the uterine spontaneous contraction increased as the [Ca++] / [Mg++] ratio increased up to 2, but the frequency decreased above this level. 6] Mg++ decreased the tension of the low[20 and 40mM] K+-contracture in the uterine smooth muscle, but the effect did not appear in the 100mM K+-contracture. From the above results, the following conclusion could be made. 1] Mg++ seems to suppress the contractility directly by acting on the smooth muscle itself, besides through the indirect action on the nerve terminal, in both the aortic and uterine smooth muscles. 2] The fact that the depressant effect of Mg++ on the K+-contracture is in inverse proportion to an increase of K+ concentration appears resulted from the extent of the opening state of the Ca++ channel. 3] Mg++ may play a depressant role on both the potential dependent and the receptor-operated Ca++ channels. 4] The relationship between the actions of Mg++ and Ca++ seems to be competitive in uterine muscle and non-competitive in aortic strip.

• Journal of Chest Surgery
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• v.39 no.4 s.261
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• pp.261-268
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• 2006

Background: Current vascular prostheses are still inadequate for reconstruction of small-diameter vessels. Autologous pericardium can be a good alternative for this purpose as it already possesses good blood compatibility and shows a mechanical behavior similar to that of natural arteries. However, the clinical use of autologous pericardial tissue as a small-diameter vascular graft has limitations due to mixed outcomes from uncertain biological behavior and difficulty to gain reliable patency results in animal experiments. To study this issue, we implanted fresh and glutaraldehyde-treated autologous pericardium as small-diameter arterial grafts in dogs, and compared their time-related changes histologically. Material and Method: As a form of 5mm-diameter arterial graft, one pair of autologous pericardial tissue was used for comparison between the glutaraldehyde-treated and the glutaraldehyde-untreated grafts in the bilateral carotid arteries in the same dog. The patency of the grafts were evaluated at regular intervals with Doppler ultrasonography. After the predetermined periods of 3 days, 2 weeks, 1 month, 3 months and 6 months, the grafts in each animal were explanted. The retrieved grafts were processed for light and electron microscopic analyses following gross observation. Result: Of 7 animals, 2 were excluded from the study because one died postoperatively due to bleeding and the other was documented as one side of the grafts being obstructed. All 10 grafts in the remaining 5 dogs were patent. Grossly, a variable degree of thromboses were observed in the luminal surfaces of the grafts at 3 days and 2 weeks, despite good patency. Pseudointimal smooth blood-contacting surfaces were developed in the grafts at f month and later. By light microscopy, mesothelial cell layers of the pericardial tissue were absent in all explanted grafts. Newly formed endothelial cell layers on the blood-contacting surface were observed in both the glutaraldehyde-treated and fresh grafts at 3 months and later. The collagen fibers became degraded by fragmentation in the fresh graft at 1 month and In the glutaraldehyde-treated graft at 3 months. At 6 months, the collagen layers were no longer visible in either the glutaraldehyde-treated or fresh grafts. By electron microscopy, a greater amount of coarse fibrin fibers were observed in the fresh grafts than in the glutaraldehyde-treated grafts and, more compact and well-arrayed layers were observed in the glutaraldehyde-treated grafts than in the fresh grafts. Conclusion: The glutaraldehyde-treated small-diameter pericardial arterial grafts showed a better endothelialization of the blood-contacting surface and a slower fragmentation of the collagen layers than the fresh grafts, although it has yet to be proven whether these differences are so significant as to affect the patency results between the groups.

• Journal of Korea Water Resources Association
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• v.50 no.11
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• pp.715-723
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• 2017

Extracellular Polymeric Substances (EPS) in the water environment assemble fine, colloidal particles, such as clays, microorganisms and biomass, in large flocs, which are eventually subject to sedimentation and deposition and determine water/sediment quality and quantity. This study hence aimed to investigate the way that water and colloidal chemistry affects EPS-mediated flocculation of colloidal particles, using a jar-test experiment. Especially, ionic strength, divalent cation and humic substances concentrations were selected as experimental variables in the jar-test experiments, to elucidate their effects on EPS-mediated flocculation. A higher ionic strength increased flocculation capability, reducing electrostatic repulsion between EPS-attached colloidal particles and enhancing particle aggregation. 0.1 M NaCl ionic strength had higher flocculation capability, with 3 times larger floc size and 2.5 times lower suspended solid concentration, than 0.001 M NaCl. Divalent cations, such as $Ca^{2+}$, built divalent cationic bridges between colloidal particles and EPS (i.e., $colloid-Ca^{2+}-EPS$ or $EPS-Ca^{2+}-EPS$) and hence made colloidal particles to build into large, settelable flocs. A small $Ca^{2+}$ concentration enhanced flocculation capability, reducing suspended solid concentration 20 times lower than the initial dosed concentration. However, humic substances, adsorbed on colloidal particles, reduced flocculation, because they blocked EPS adsorption on colloidal particles and increased negative charges and electrostatic repulsion of colloidal particles. Suspended solid concentration in the tests with humic substances remained as high as the initial dosed concentration, indicating stabilization rather than flocculation. Findings about EPS-mediated flocculation in this research will be used for better understanding the fate and transport of colloidal particles in the water environment and for developing the best management practices for water/sediment quality.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.2
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• pp.129-136
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• 1973

In order to study the effects of climatic factors on barley responses to NPK fertilizers, the responses under the conditions of cold, moisture and drought damages and in different temperature regions, Nothern, Central, and Southern, which were devided according to average temperature for growing season of barley (from Nov. to May) were investigated from the results of NPK experiments which were carried out from Nov., 1965 to May 1969. The relationships between occurrence rate of cold, moisture, and drought damages and average or average lowest temperature in winter (Dec., Jan., and Feb), and the amount of precipitation in spring (Mar., Apr,. and May) were also investigated. 1. The lower the average lowest temperature, the higher the occurrence rate of cold damage of barley. When affected by cold damage, barley responded more significantly to P and K fertilizers. 2. The more the amount of precipitation in spring, the more the moisture damage and the less the drought damage. Damage from both moisture and drought were the lowest at 280mm. Since the average precipitation in spring in Korea is 230mm, drought damage is always more problem in terms of occurrence of damage, but total yield reduction is greater by moisture damage. 3. When affected by moisture damage, barley responded more to P and K fertilizers. In case of drought damage, only response to K was recognizable. 4. The reductions of barley yield due to cold, moisture, and drought damages were in average 31 (29-33), 42, and 19(12-25)%, respectively. 5. Average barley responses to NPK fertilizers were 44(34-58), 19(5-38), and 9(1-34)%, respectively by percent responses with regard to maximum possible yields. 6. Responses to nitrogen increased as the sunshine hours increased. Under dry condition, the response increased as the precipitation increased. However if the amount of precipitation was excessive or too little, the response was dropped markedly. 7. The responses to P and K were higher in North than South to the same degree. As the average temperature for growing season of barley (from Nov. to May) increased by $1^{\circ}C$, the percent responses to both P and K increased by 4.3%.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.17-21
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• 1970

To determine the effects of the silicate and the phosphate on the rice seedlings, 200 grams dry soil of the paddy field taken in the petri dish of 15cm diameter were treated with three levels of silicate(wollastonite) and phosphate. And the same amounts of nitrogen and potash were added constantly to each treated petridish. 100 grains of rice of which variety is Nongrim 25 were sown on each treated petridish simultaneously. After five times continuous culture, the rice plants and the soil were analyzed chemically and the results obtained are summarized as follows: 1. Dry matter weight of the rice seedlings was significantly increased to the increased phosphate absorption, on the other hand that was decreased when the silica absorption was increased. 2. The higher the available phosphate content in the soil after the experiments, the lower the silica content as well as absorption by the plant, and the $SiO_2/P_2O_5$ ratio in the plant was significantly decreased. 3. By the wollastonite application, the available silica, the exchangeable calcium in the soil after the experiment, and the silica content as well as silica absorption and $SiO_2/P_2O_5$ ratio in the rice plant was significantly increased. 4. Higher correlation coefficient was obtained between the exchangeable calcium amount and the silica content or silica/phosphate ratio in the rice plant than the available silica content in soil itself. 5. It is possible to control the silica/phosphate ratio in plant by the control of the silica/phosphate ratio in soil. 6. The relation between the silica/phosphate ratio in plant (y) and the available silica/phosphate ratio in soil (x) was $y=0.665+1.420x-0.0825x^2$ and the goodness of fit(r) was 82%.