• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.40-44
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• 2003

Soil-borne infectious disease including Pythium aphanidermatum and Rhizoctonia solani causes severe damage to plants, such as cucumber. This soil-borne infectious disease was not controlled effectively by chemical pesticide. Since these diseases spread through the soil, chemical agents are usually ineffective. Instead, biological control, including antagonistic microbe can be used as a preferred control method. An efficient method was developed to select an antagonistic strain to be used as a biological control agent strain. In this new method, surface tension reduction potential of an isolate was included in the ‘decision factor’ in addition to the other factors, such as growth rate, and pathogen inhibition rate. Considering these 3 decision factors by a statistical method, an isolate from soil was selected and was identified as Bacillus sp. GB16. In the pot test, this strain showed the best performance among the isolated strains. The lowest disease incidence rate and fastest seed growth was observed when Bacillus sp. GB16 was used. Therefore this strain was considered as plant growth promoting rhizobacteria (PGPR). The action of surface tension reducing component was deduced as the enhancement of wetting, spreading, and residing of antagonistic strain in the rhizosphere. This result showed that new selection method was significantly effective in selecting the best antagonistic strain for biological control of soil-borne infectious plant pathogen. The antifungal substances against P. aphanidermatum and R. solani were partially purified from the culture filtrates of Bacillus sp. GB16. In this study, lipopeptide possessing antifungal activity was isolated from Bacillus sp. GB16 cultures by various purification procedures and was identified as a surfactin-like lipopeptide based on the Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), high performance liquid chromatography mass spectroscopy (HPLC-MS), and quadrupole time-of-flight (Q-TOF) ESI-MS/MS data. The lipopeptide, named GB16-BS, completely inhibited the growth of Pythium aphanidermatum, Rhizoctonia solani, Penicillium sp., and Botrytis cineria at concentrations of 10 and 50 mg/L, respectively. A novel method to prevent the foaming and to provide oxygen was developed. During the production of surface active agent, such as lipopeptide (surfactin), large amount of foam was produced by aeration. This resulted in the carryover of cells to the outside of the fermentor, which leads to the significant loss of cells. Instead of using cell-toxic antifoaming agents, low amount of hydrogen peroxide was added. Catalase produced by cells converted hydrogen peroxide into oxygen and water. Also addition of corn oil as an oxygen vector as well as antifoaming agent was attempted. In addition, Ca-stearate, a metal soap, was added to enhance the antifoam activity of com oil. These methods could prevent the foaming significantly and maintained high dissolved oxygen in spite of lower aeration and agitation. Using these methods, high cell density, could be achieved with increased lipopeptide productivity. In conclusion to produce an effective biological control agent for soil-borne infectious disease, following strategies were attempted i) effective screening of antagonist by including surface tension as an important decision factor ii) identification of antifungal compound produced from the isolated strain iii) novel oxygenation by $H_2O_2-catalase$ with vegetable oil for antifungal lipopeptide production.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1523-1523
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• 2001

The wine industry requires practical methods for objectively measuring the composition of both red wine grapes on the vine to determine optimal harvest time; and of freshly harvested grapes for efficient allocation to vinery process streams for particular red wine products, and to determine payment of contract grapegrowers. To be practical for industry application these methods must be rapid, inexpensive and accurate. In most cases this restricts the analyses available to measurement of TSS (total soluble solids, predominantly sugars) by refractometry and pH by electropotentiometry. These two parameters, however, do not provide a comprehensive compositional characterization for the purpose of winemaking. The concentration of anthocyanin pigment in red wine grapes is an accepted indicator of potential wine quality and price. However, routine analysis for total anthocyanins is not considered as a practical option by the wider wine industry because of the high cost and slow turnaround time of this multi-step wet chemical laboratory analysis. Recent work by this ${group}^{l,2}$ has established the capability of near infrared (NIR) spectroscopy to provide rapid, accurate and simultaneous measurement of total anthocyanins, TSS and pH in red wine grapes. The analyses may be carried out equally well using either research grade scanning spectrometers or much simpler reduced spectral range portable diode-array based instrumentation. We have recently expanded on this work by collecting thousands of red wine grape samples in Australia. The sample set spans two vintages (1999 and 2000), five distinct geographical winegrowing regions and three main red wine grape varieties used in Australia (Cabernet Sauvignon, Shiraz and Merlot). Homogenized grape samples were scanned in diffuse reflectance mode on a FOSE NIR Systems6500 spectrometer and subject to laboratory analysis by the traditional methods for total anthocyanins, TSS and pH. We report here an analysis of the correlations between the NIR spectra and the laboratory data using standard chemometric algorithms within The Unscrambler software package. In particular, various subsets of the total data set are considered in turn to elucidate the effects of vintage, geographical area and grape variety on the measurement of grape composition by NIR spectroscopy. The relative ability of discrete calibrations to predict within and across these differences is considered. The results are then used to propose an optimal calibration strategy for red wine grape analysis.

• Journal of Animal Science and Technology
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• 제44권1호
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• pp.135-144
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• 2002

본 실험은 우리 나라의 양돈농가에서 노동력 절감이라는 이점 때문에 자돈사 및 분만사의 무창돈사는 일반농가에까지 보급되고 있으나, 육성.비육돈사에 있어서 무창돈사는 거의 전무한 실정으로 질병의 근원적인 차단 및 관리를 위하여 지금까지 회피되어 왔던 무창 육성.비육돈사의 활성화를 위하여 환기시스템을 자체적으로 고안하여 최적의 환기시스템을 여름철 및 겨울철로 구분하여 건축하였으며, 자체적으로 고안한 환기시스템의 성능을 평가하고자 겨울철 및 여름철로 구분하여 시험한 결과를 요약하면 다음과 같다. 1. 무창 육성.비육돈사에 있어서 돼지 생활공간(하부) 지점에서의 공기유속은 겨울철 최소환기 수준(1,440 $m^3/h$)으로 하였을 때 0-0.19 m/s 였으며, 여름철 최대환기 수준(24,000 $m^3/h$)에서는 0.07-0.42 m/s로 분포되어 여름철 및 겨울철의 무창돈사내 공기유속으로 보아 환기시스템이 우수하였다. 이상의 실험결과를 종합해 보면 무창 육성.비육사의 환기시스템은 여럼츨 때는 측벽을 통한 환기와 겨울철은 천장을 통한 환기시스템이 적합하다고 판단되었으며, 한쪽 측벽에 의한 배기시스템이라도 입기구는 양쪽 측벽을 통한 입기가 우수하다는 것을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2648-2656
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• 2011

A simple HPLC-DAD method was developed and validated to determine B group vitamin content (thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxine and folic acid) in supplemented food samples, i.e., infant formula, cereal, low-calorie food, a multi-vitamin pill and a vitamin drink. In this study, the most significant advantages were simultaneous determination of the six B group vitamins in various food matrices and a small number of sample treatment steps that required only an organic solvent, acetonitrile. Moreover, this method prevents reduction of column durability, because the mobile phase does not contain ion-pairing reagents. Analytes were separated on a Develosil RPAQUEOUS $C_{30}$ (4.6 mm ${\times}$ 250 mm, 5 ${\mu}M$ particle size) column with a gradient elution of acetonitrile and 20 mM phosphate buffer (pH 3.0) at a flow rate between 0.8 and 1.0 mL/min. Detection was performed at 275 nm, except for that of pantothenic acid (205 nm). The calibration curves for all six vitamins showed good linearity with correlation coefficients ($r^2$) higher than 0.995. The developed method was validated with respect to linearity, intra- and inter-day accuracy and precision, limit of quantification (LOQ), recovery and stability. The method showed good precision and accuracy, with intra- and inter-assay coefficients of variation less than 15% at all concentrations. The recovery was carried out according to the standard addition procedure, with yields ranging from 89.8 to 104.4%. This method was successfully applied to the determination of vitamin B groups in supplemented food products.

• 천문학회보
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• 제37권1호
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• pp.42-42
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• 2012

The First stars (Pop.III stars) in the universe are expected to be formed between the recombination era at z - 1100 and the most distant quasar (z - 8). They have never been directly detected due to its faintness so far, but can be observed as a background radiation at around 1${\mu}m$ which is called the Cosmic Near-Infrared Background (CNB). Main part of the CNB is thought to be redshifted Lyman-alpha from gas clouds surrounding the Pop.III stars. Until now, the COBE (COsmic Background Explorer) and the IRTS (Infrared Telescope in Space) observed excess emission over the background due to galaxies. To confirm the COBE and the IRTS results and pursue more observational evidences, we carried out the sounding rocket experiment named the Cosmic Infrared Background ExpeRiment (CIBER). The CIBER is successfully launched on July 10, 2010 at White Sands Missile Range, New Mexico, USA. It consists of three kinds of instruments. We report the results obtained by LRS (Low Resolution Spectrometer) which is developed to fill the uncovered spectrum around 1${\mu}m$. LRS is a refractive telescope of 5.5 cm aperture with spectral resolution of 20 - 30 and wavelength coverage of 0.7 to 2.0${\mu}m$. After subtracting foreground components (zodiacal light, integrated star light and diffuse galactic light) from the sky brightness of observed five fields, there remained significant residual emission (even for the lower limit case) consistent with the IRTS and the COBE results. In addition, there exists a clear gap at 0.7 - 0.8${\mu}m$ in the CNB spectrum over the background due to galaxies according to recent results (Matsuoka et al. 2011; Mattila et al. 2011). The origin of the excess emission could be ascribed to the Pop.III stars with its active era of z = 7 - 10.

• 대한화학회지
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• 제21권5호
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• pp.307-319
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• 1977

Thiourea derivative인 $N-({\alpha}-dimethyl\;{\beta}-hydroxy)ethyl\;N'-cyclohexyl\;thiourea,\;C_{ll}H_{22}N_2OS)$의 결정 및 분자구조를 X-선 회절법으로 해명하였다. 이 화합물의 결정은 공간군 $P_{bca}$에 속하는 orthorhombic 형으로 a = 10.33(3), b = 11.82(3), c = 22.57(4)${\AA}$ 이고 Z = 8이다. Weissenberg 사진촬영으로 얻은 회절반점의 총수는 1414개이며 중원자법을 이용하여 구조해명을 한 후 최소자승법으로 정밀화하였으며 최종 R값은 0.13이다. Cyclohexane ring은 normal chair conformation을, thiourea 부분은 평면을 이루고 있다. 일차 알코올의 hydroxyl group은 N(2)원자와 분자내 수소결합을 이뤄서 전체분자를 안정화시키고 있다. 분자들은 결정내에서 수소결합과 van der Waals힘으로 서로 결합되어 있다. 분자내 수소결합 N(2)-H${\cdot}{\cdot}{\cdot}$O는 강한 수소결합으로 N${\cdot}{\cdot}{\cdot}$O 길이는 2.71${\AA}$이고, 분자간 수소결합 O${\cdot}{\cdot}{\cdot}$H${\cdot}{\cdot}{\cdot}$S의 O${\cdot}{\cdot}{\cdot}$S 길이는 3.02${\AA}$으로 b축에 나란하다.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2342-2348
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• 2014

Poly(lactic-co-glycolic acid) (PLGA) were grafted to both ends of Pluronic$^{(R)}$ F68 ($(EO)_{75}(PO)_{30}(EO)_{75}$) triblock copolymer to produce poly{(lactic acid)$_m$-co-(glycolic acid)$_n$}-b-poly(ethylene oxide)$_{75}$-b-poly(propylene oxide)$_{30}$-b-poly(ethylene oxide)$_{75}$-b-poly{(lactic acid)$_m$-co-(glycolic acid)$_n$} (PLGA-F68-PLGA) pentablock copolymers. Molecular weights of PLGA blocks were controlled and five kinds of pentablock copolymers with different PLGA block lengths were synthesized using in-situ ring-opening polymerization of D,L-lactide and glycolide with tin(II) 2-ethylhexanoate ($Sn(Oct)_2$) catalyst. PLGA-F68-PLGA pentablock copolymers were characterized by $^1H$- and $^{13}C$-NMR, GPC, and TGA. The numbers (2m, 2n) of repeating units for lactic acid and glycolic acid inside PLGA segments were obtained as (48, 17), (90, 23), (125, 40), (180, 59), and (246, 64), with $^1H$-NMR measurement. From NMR data, the resultant molecular weights were determined in the range of 12,700-29,700, which were similar to those obtained from GPC. Polydispersity index was increased in the range of 1.32-1.91 as the content of PLGA blocks increased. TG and DTG thermograms showed discrete degradation traces for PLGA and F68 blocks, which indicate the weight fractions of PLGA blocks in pentablock copolymers can be calculated by TG profile and it is possible to remove PLGA block selectively. Hydrodynamic radius and radius of gyration of pentablock copolymer micelle were obtained in the range of 46-68 nm and 31-49 nm, respectively, in very dilute (i.e. 0.005 wt %) aqueous solution of THF:$H_2O$ = 10:90 by volume at $25^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• 제28권1호
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• pp.37-49
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• 2015

During pregnancy, the maternal body undergoes significant physiological changes. The present study assessed the changes on calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na) and potassium (K) metabolism in singleton and twin-pregnant dairy goats. The 42 goats used ($49.5kg{\pm}7.6$ body weight [BW]) were assigned at random to treatments that were factorially arranged to account for 2 breeds (Oberhasli and Saanen), 2 pregnancy types (singleton and twin) and 3 gestation periods (80, 110, and 140 days). Digestibility trials were performed at 80, 110, and 140 days of gestation. Mineral retention during pregnancy was determined in the maternal body, femur, uterus, mammary gland, fetus and fetal fluid. Blood samples were taken during pregnancy before and after a meal, and Ca, P, Mg, Na, K ions and alkaline phosphatase activity determined in serum. Bone mineral density was determined in the right femur. Statistical analyses were performed using the SAS MIXED procedure. Dry matter intake decreased linearly up to 140 days of gestation. Maternal BW gain, and Ca, P, and Mg retention (g/kg) decreased linearly with the advance of gestation days. Macromineral retention in maternal body (g/kg) was greater in Oberhasli than Saanen goats, and their fetuses had higher Ca, P, and Mg deposition (mg/g). Mineral retention (mg/g) increased in fetuses according to pregnancy development, with no differences between singleton and twin pregnancy. In the mammary gland, the retention of all minerals (g) increased with the days of pregnancy. In conclusion, related to Ca, P, and Mg metabolism can be divided into two stages. Up to 80 days of gestation, was characterized by the preparation of the maternal body reserves for future mineral demands. From 80 days of gestation onward, was characterized by the transfer of maternal body reserves for fetal development and colostrum production. Na and K supply was provided by adjustments in endogenous excretion and an increase in intestinal absorption. Finally, mineral metabolism was specific to each genotype and, except for Na, was not affected by the number of fetuses.

• Asian-Australasian Journal of Animal Sciences
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• 제23권2호
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• pp.246-252
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• 2010

In order to improve the availability of phytase and probiotics together, a phytase gene from Aspergillus ficuum has been expressed in Lactobacillus. In this study, the transformed Lactobacillus with phytase gene was fed to pigs to determine its effect on pig production, feed conversion and gut microbes. Forty eight, 60-day-old, castrated pigs (Duroc${\times}$Landrace${\times}$Pietrain) were assigned to 6 groups, 8 pigs for each group. Group 1 was the control, group 2 was added with chlortetracycline (500 mg/kg), group 3 was added with the transformed Lactobacillus (500 mg/kg) with 20% (w/w) of calcium monohydrogen phosphate (CMP, $CaHPO_{4}$) removed, group 4 was added with the natural Lactobacillus (500 mg/kg) with 20% (w/w) of CMP removed, group 5 was added with the transformed Lactobacillus (500 mg/kg) with 40% (w/w) of CMP removed, group 6 was added with phytase (500 mg/kg) with 40% (w/w) of CMP removed. The results showed: i) the average daily gain (ADG) was improved in groups 2, 3 and 4 (p<0.05); ii) the diarrhea rates in the groups added with Lactobacillus were lower than in the other groups (p<0.05), in which the transformed Lactobacillus had more effect on reducing digestive disease; iii) the transformed Lactobacillus was most effective in improving the digestibilities of crude protein (CP), calcium (Ca), phosphorus (P), compared with the other groups (p<0.05); iv) Lactobacillus could increase lactic acid bacterium number and ammonia concentrations, and decrease pH values and E. coli number in pig feces (p<0.05); v) the phytase activity in the feces of pigs fed with the transformed Lactobacillus was 133.32 U/g, which was higher than in group 4 (9.58 U/g, p<0.05), and was almost the same as group 6 (135.94 U/g); vi) the transformed Lactobacillus could increase serum concentrations of IgA, triglyceride, and glutamic oxaloacetic transaminase activity (p<0.05), and had no significant effect on other serum indexes (p>0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제13권7호
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• pp.948-956
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• 2000

The effect of high and low level of feed intakes on nutrient digestibility, nutrient losses through methane, energy and protein utilization by goats fed on alfalfa (Medicago sativa L.) pellets based diets was investigated in this study. Twelve castrated Japanese goats were employed in two subsequent digestion and metabolism trials. The goats were divided into three groups, offered three diets. Diet 1 consisted of 100% alfalfa pellet, Diet 2 was 70% alfalfa pellet and 30% corn, and Diet 3 was 40% alfalfa pellet and 60% corn. The two intake levels were high (1.6 times) and low (0.9 times) the maintenance requirement of total digestible nutrients (TON). Rumen ammonia nitrogen ($NH_3$-N) level of Diet 1 was lower (p<0.001) compared to Diets 2 and 3, but the values were always above the critical level (I50 mg/liter), The pH values of rumen liquor ranged from 6.02 to 7.30. Apparent digestibility of nutrient components did not show differences (p>0.05) between the two intake levels but inclusion of corn significantly altered the nutrient digestibility. Diet 3 had highest (p<0.001) dry matter (DM), organic matter (OM), ether extract (EE) and nitrogen fee extract (NFE) digestibility followed by the Diet 2 and Diet 1. The crude protein (CP) digestibility values among the three diets were in a narrow range (70.1 to 70.8%). Crude fiber (CF) digestibility for Diet 3 was slight higher (p>0.05) than that for other two diets. When alfalfa was replaced by corn, there were highly significant (p<0.001) increases in DM, OM, EE and NFE apparent digestibility and a slight increase in the CF digestibility (p>0.05). There were no differences (p>0.05) in energy losses as methane ($CH_4$) and heat production among the diets but energy loss through urine was higher for the Diet 1. The total energy loss as $CH_4$ and heat production were higher for the high intake level but the energy loss as $CH_4$ per gram DM intake were same (0.305 kcal/g) between the high and low intake level. Retained energy (RE) was higher for Diet 3 and Diet 2. Nitrogen (N) losses through feces and urine were higher (p<0.001) for Diet 1. Consequently, N retention was lower (p>0.05) for Diet 1 and higher in Diets 3 and 2. It is concluded that inclusion of corn with alfalfa increased the metabolizable energy (ME) and RE, and retained N through reducing the energy and N losses. The high level of intake reduced the rate of nutrient losses through feces and urine.