• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.406-411
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• 2006

The objective of this study was to investigate the effects of feeding probiotic (Enterococcus faecium SF68, EF) on growth performance, nutrient digestibility, blood characteristics and faecal noxious gas content in finishing pigs. A total of eighty [($Landrace{\times}Yorkshire$)${\times}Duroc$] pigs with an initial BW of $50.47{\pm}2.13kg$ were used in this 8-week experiment. Pigs were allotted to four treatments (4 replicates per treatment and 5 pigs per pen) according to a randomized complete block design. Dietary treatments were: 1) CON (control; basal diet), 2) CTC (control diet+0.1% antibiotic, chlortetracycline), 3) EF1 (control diet+0.1% probiotic, EF) and 4) EF2 (control diet+0.2% probiotic, EF). During weeks 0-4, ADG was not affected by the addition of antibiotic or EF (p>0.05). In weeks 4-8, ADG tended to increase in CTC and EF treatments compared to CON treatment (p<0.10). ADFI and gain/feed were not affected in each 4-week period and the entire experimental period (p>0.05). Digestibilities of DM and N were higher in EF supplemented treatments than in CON and CTC treatments (p<0.05). Blood characteristics of WBC, RBC and lymphocyte were not affected in pigs given diets containing EF (p>0.05). Supplementation of EF in the diet decreased faecal ammonia nitrogen ($NH_3$-N) and hydrogen sulphide ($H_2S$) concentrations (p<0.05). Faecal acetic acid concentration tended to decrease (p<0.10) while propionic acid and butyric acid concentrations were significantly lower on diets with EF supplementation than on the diet containing antibiotic (p<0.05). In conclusion, dietary supplementation of EF can increase nutrient digestibility and decrease faecal $NH_3$-N, $H_2S$ and volatile fatty acid (VFA) concentrations in finishing pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.4
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• pp.597-604
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• 2020

Objective: This study was conducted to investigate the effect of zinc aspartic acid chelate (Zn-ASP) on growth performance, nutrient digestibility, blood profiles, fecal microbial and fecal gas emission in growing pigs. Methods: A total of 160 crossbred ([Landrace×Yorkshire]×Duroc) growing pigs with an initial body weight (BW) of 25.56±2.22 kg were used in a 6-wk trial. Pigs were randomly allocated into 1 of 4 treatments according to their sex and BW (8 replicates with 2 gilts and 3 barrows per replication pen). Treatments were as follows: i) CON, basal diet, ii) TRT1, CON+0.1% Zn-ASP, iii) TRT2, CON+0.2% Zn-ASP, and iv) TRT3, CON+0.3% Zn-ASP. Pens were assigned in a randomized complete block design to compensate for known position effects in the experimental facility. Results: In the current study, BW, average daily gain, and gain:feed ratio showed significant improvement as dietary Zn-ASP increased (p<0.05) in growing pigs. Apparent total tract digestibility (ATTD) of dry matter was increased linearly (p<0.05) in pigs fed with Zn-ASP diets. A linear effect (p<0.05) was detected for the Zn concentration in blood with the increasing levels of Zn-ASP supplementation. Lactic acid bacteria and coliform bacteria were affected linearly (p<0.05) in pigs fed with Zn-ASP diets. However, no significant differences were observed in the ATTD of nitrogen, energy and Zn. And dietary Zn-ASP supplementation did not affect fecal ammonia, hydrogen sulfide and total mercaptans emissions in growing pigs. Conclusion: In conclusion, dietary supplementation with Zn-ASP of diet exerted beneficial effects on the growth performance, nutrient digestibility, blood profiles and fecal microbes in growing pigs.

• Journal of the Korean Vacuum Society
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• v.19 no.1
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• pp.58-65
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• 2010

AlN thin films were deposited on sapphire substrates and ZnO templates by rf-magnetron sputtering. Powder-sintered AlN target was adopted for source material. Thickness of AlN layer was linearly dependent on plasma power from 50 to 110 W, and it decreased slightly when working pressure increased from 3 to 10 mTorr due to short mean free path of source material sputtered from AlN target by Ar working gas. When $N_2$ gas was mixed with Ar, the thickness of AlN layer decreased significantly because of low sputter yield of nitrogen. AlN layer was also deposited on ZnO template. However, it showed weak thermal stability that the interface between AlN and ZnO was deteriorated by rapid thermal annealing treatment above $700^{\circ}C$. In addition, ZnO layer was largely attacked by MOCVD ambient gas of hydrogen and ammonia around $700^{\circ}C$ through inferior AlN layer deposited by sputtering. And AlN layers were fully peeled off above $900^{\circ}C$.

• Korean Journal of Materials Research
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• v.20 no.12
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• pp.691-698
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• 2010

Magnesium hydroxide-melamine core-shell particles were prepared through the coating of melamine monomer on the surface of magnesium hydroxide in the presence of phosphoric acid. The melamine monomer was dissolved in hot water but recrystallized on the surface of magnesium hydroxide by quenching to room temperature in the presence of phosphoric acid. The core-shell particle was applied to low-density polyethylene/ ethylene vinyl acetate (LDPE/EVA) resin by melt-compounding at $180^{\circ}C$ as flame retardant. The effect of magnesium hydroxide and melamine content has been studied on the flame retardancy of the core-shell particles in LDPE/EVA resin according to the preparation process and purity of magnesium hydroxide. Magnesium hydroxide prepared with sodium hydroxide rather than with ammonia solution revealed higher flame retardancy in core-shell particles with LDPE/EVA resin. At 50 wt% loading of flame retardant, core-shell particles revealed higher flame retardancy compared to that of the exclusive magnesium hydroxide in LDPE/EVA composite, and it was possible to satisfy the V0 grade in the UL-94 vertical test. The synergistic flame retardant effect of magnesium hydroxide and melamine core-shell particles was explained as being due to the endothermic decomposition of magnesium hydroxide and melamine, which was followed by the evolution of water from the magnesium hydroxide and porous char formation due to reactive nitrogen compounds, and carbon dioxide generated from melamine.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1577-1584
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• 2010

In total, 140 halotolerant bacterial strains were isolated from both the soil of barren fields and the rhizosphere of six naturally growing halophytic plants in the vicinity of the Yellow Sea, near the city of Incheon in the Republic of Korea. All of these strains were characterized for multiple plant growth promoting traits, such as the production of indole acetic acid (IAA), nitrogen fixation, phosphorus (P) and zinc (Zn) solubilization, thiosulfate ($S_2O_3$) oxidation, the production of ammonia ($NH_3$), and the production of extracellular hydrolytic enzymes such as protease, chitinase, pectinase, cellulase, and lipase under in vitro conditions. From the original 140 strains tested, on the basis of the latter tests for plant growth promotional activity, 36 were selected for further examination. These 36 halotolerant bacterial strains were then tested for 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Twenty-five of these were found to be positive, and to be exhibiting significantly varying levels of activity. 16S rRNA gene sequencing analyses of the 36 halotolerant strains showed that they belong to 10 different bacterial genera: Bacillus, Brevibacterium, Planococcus, Zhihengliuella, Halomonas, Exiguobacterium, Oceanimonas, Corynebacterium, Arthrobacter, and Micrococcus. Inoculation of the 14 halotolerant bacterial strains to ameliorate salt stress (150 mM NaCl) in canola plants produced an increase in root length of between 5.2% and 47.8%, and dry weight of between 16.2% and 43%, in comparison with the uninoculated positive controls. In particular, three of the bacteria, Brevibacterium epidermidis RS15, Micrococcus yunnanensis RS222, and Bacillus aryabhattai RS341, all showed more than 40% increase in root elongation and dry weight when compared with uninoculated salt-stressed canola seedlings. These results indicate that certain halotolerant bacteria, isolated from coastal soils, have a real potential to enhance plant growth under saline stress, through the reduction of ethylene production via ACC deaminase activity.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1168-1177
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• 2018

The aim of this study was to investigate the microbial community of three tannery wastewater treatment plants (WWTPs) involved in nitrification by Illumina MiSeq sequencing. The results showed that highly diverse communities were present in tannery wastewater. A total of six phyla, including Proteobacteria (37-41%), Bacteroidetes (6.04-16.80), Planctomycetes (3.65-16.55), Chloroflexi (2.51-11.48), Actinobacteria (1.91-9.21), and Acidobacteria (3.04-6.20), were identified as the main phyla, and Proteobacteria dominated in all the samples. Within Proteobacteria, Beta-proteobacteria was the most abundant class, with the sequence percentages ranging from 9.66% to 17.44%. Analysis of the community at the genus level suggested that Thauera, Gp4, Ignavibacterium, Phycisphaera, and Arenimonas were the core genera shared by at least two tannery WWTPs. A detailed analysis of the abundance of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) indicated that Nitrosospira, Nitrosomonas, and Nitrospira were the main AOB and NOB in tannery wastewater, respectively, which exhibited relatively high abundance in all samples. In addition, real-time quantitative PCR was conducted to validate the results by quantifying the abundance of the AOB and total bacteria, and similar results were obtained. Overall, the results presented in this study may provide new insights into our understanding of key microorganisms and the entire community of tannery wastewater and contribute to improving the nitrogen removal efficiency.

• Korean Journal of Environmental Biology
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• v.18 no.3
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• pp.355-365
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• 2000

In order to study the relationship between water quality and phytoplankton standing crops, the authors investigated the physicochemical factors, phytoplankton standing crops and chlorophyll-a at two stations in the Daechung Reservoir during the period from May to November 1998. Nutrients (nitrite, nitrate, ammonia and phosphate) have gradually increased more than those of the previous reports. Concentrations of the total nitrogen, phosphorus, chlorophyll -a and transparency exceeded the standard value of eutrophication. It could be assumed that the eutrophication of the Daechung reservoir was caused by various pollutants. Chlorophyll-a concentration was under the influence of phytoplankton standing crops, but very tiny cell-sized blue-green algae were less important in regards to the chlorophyll-a. Except at station 1 from July to August, phytoplankton standing crops bloomed during the time of the survey. Spring phytoplankton blooms caused by nitrate and phosphate in the surface layer. High concentrations of the suspended solids in July and August were caused by an inflow of them due to heavy rains. Density of heterotrophic bacteria was high in August owing to the high water temperatures and the organic nutrients which were from the nearby reservoir.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.442-447
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• 2001

A 2-year-old 4.0-kg female Shih Tzu with history of hematemesis and melena was referred to Veterinary Medical Teaching Hospital, Seoul national University for further evaluation and treatment. During physical examination, the dog revealed mild depression, dry mucous membrane and abdominal pain. Hematologic values were normal and serum chemical values showed increased serum bile acid (53.47 umol/l, preprandial), fasting serum ammonia concentration (184 g/dl), alanine transferase (98 U/L), alkaline phosphatase (871 U/L) and gamma glutamyl transpeptidase (21 U/L), and decreased blood urea nitrogen (4 mg/dl), total protein (4.1 g/dl) and albumin (1.2 g/dl). Microhepatica was shown in abdominal radiography. During the ultrasound examination, dilated tortuous vein communicating with caudal vena cava ws observed near the stomach. Intraoperative jejunal vein portography was performed during laparotomy to confirm the location and size of shunt vessel. According to history taking, physical examination, hematologic and serum chemical examination and radiographic study, it was diagnosed as single extrahepatic portosystemic shunt. The anomalous vessel (7 mm, o.d.) that enter the caudal vena cava from the left gastric vein, near the level of the diaphragm, was identified. A Ameroid constrictor (5 mm, i.d.) was applied to the shunting vessel near the caudal vena cava. Hematologic and serum chemical values recovered gradually and were revealed normal values 4 months after surgery. Four month after surgery serum bile acids concentrations were 0.56 $\mu$mol/l (preprandial) and 18.45 umol/l (postprandial). Abdominal radiograph showed normal gastric axis and it revealed normal size of the liver. Fine texture and increased echogenecity of liver and enlargement of portal vein were shown in ultrasonography. Single extrahepatic portosystemic shunt might be treated surgically using Ameroid constrictor.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.920-926
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• 2007

The upflow Biobead$^{(R)}$ process, one of biological aerated filters (BAF), which was used commercially, invented for removal of organic materials and nitrification. This process was modified to enhance the ability of denitrification through the induction of pre-anoxic tank. In this research, we investigated the effects of hydraulic retention time (HRT) and backwashing period in aerobic tank. The characteristics of nitrifying bacteria, which are composed of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), also investigated using fluorescence in situ hybridization (FISH). Even though the HRT was shortened, the efficiency of nitrification was not decreased when the organic loading rate and ammonium-nitrogen loading rate were $2.10kg/m^3/day$ and $0.25kg/m^3/day$, respectively. And then the distribution ratios of AOB and NOB showed the similar patterns. However, when the backwashing period was lengthened from 12 hours to 24 hours in aerobic 1 tank, the nitrification efficiency was decreased to 63.9% from 89.2%. The results of FISH explained that this decrease of nitrification efficiency was caused by the decrease of distribution ratio of AOB in aerobic 1 tank. The nitrification efficiencies of aerobic 1 and aerobic 2 tank were increased when the backwashing period was lengthened because of relative high distribution ratios of nitrifying bacteria.

• Korean Journal of Food Science and Technology
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• v.5 no.4
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• pp.210-214
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• 1973

This study analyses and compares the amino acid composition and available lysine content between Korean fermented soybean Meju and its products as well as home-made and commercially made products. The protein quality of the products was evaluated by the result, and the biological value of the proteins was estimated by using the regression equation for chemical score to biological value as calculated by B.O. Eggum. The amino-N content of soybean is found to be 85% of the total nitrogen content and is reduced to approximately 75% in the fermented products except home-made soysauce, where as the content of ammonia-N and other N-compounds is increased. The difference in protein quality between home-made and commercially made products is not found to be significant. The protein quality of soybean is not damaged greatly in the making of Meju but is seriously damaged during the long periods of ripening. After the ripening the chemical score of the products' protein is reduced to approximately one half of the original soybean protein and the available lysine content to $1/3{\sim}1/2$.