• Tuberculosis and Respiratory Diseases
• /
• v.48 no.1
• /
• pp.33-44
• /
• 2000

Background: To evaluate airway responses and inflammation to antigen in Sprague-Dawley rat asthma model, we examined airway responses, serial histologic changes of the lung, and the relationship between airway responses and airway inflammation after antigen airway challenge. Methods: Sprague-Dawley rats were sensitized with subcutaneous injection of 10 ${\mu}g$ ovalbumin(OA). Antigen airway challenges were done 14~16 days after sensitization and the sensitized rats were sacrificed 1h($A_E$), 6~8h($A_L$) and 1day($A_D$) after airway challenge, to examine the histologic changes of the lung. Airway responses were measured by body plethysmograph and recorded by enhanced pause(Penh) as an index of airway obstruction 6~8h after antigen challenges. Nonsensitized controls(10 rats) were also challenged with antigen and sacrificed 1 day later. Histopathologic examination of two trachea, large bronchi, small bronchi, and vessels was performed to evaluate the severity of inflammation and eosinophilic infiltration with H&E stain. Results: In 17 of 20 rats(85%) in both groups, we observed airway responses. Among them, an early response(ER) in 15 rats(75%), an dual response in 5(25%), and an late response(LR) only in 2 rats(10%) displayed. There were no significant differences in the severity of inflammation among the trachea, large bronchi, small bronchi and vessels in all groups after antigen challenge(p>0.05) and between early and late responders. The significant eosinophil infiltration was observed in 5 rats(50%) of AL(p<0.05) compared with in AE and controls. Also, eosinophil infiltration was observed in higher trend in LR(57.1%) compared to ER(40%)(p>0.05). Conclusion: Sprague-Dawley rats sensitized with subcutaneous injection of OA showed a significant airway responses to antigen challenge. But antigen challenges caused a little eosinophil infiltration and no significant airway inflammation. Asthma model of Sprague-Dawley rats could be useful for antigen-induced airway responses, but this model has a limitation for the study of human asthma because of no significant pathologic change.

• Journal of Magnetics
• /
• v.9 no.1
• /
• pp.17-22
• /
• 2004

We studied the magnetotransport properties of tunnel junctions with AlO and AlN barriers fabricated using microwave-excited plasma. The plasma nitridation process provided wider controllability than the plasma oxidization for the formation of MTJs with ultra-thin insulating layer, because of the slow nitriding rate of metal Al layers, comparing with the oxidizing rate of them. High tunnel magnetoresistance (TMR) ratios of 49 and 44% with respective resistance-area product $(R{\times}A) of 3 {\times} 10^4 and 6 {\times} 10^3 {\Omega}{\mu}m^2$ were obtained in the Co-Fe/Al-N/Co-Fe MTJs. We conclude that AlN is a hopeful barrier material to realize MTJs with high TMR ratio and low $R{\times}A$ for high performance MRAM cells. In addition, in order to clarify the annealing temperature dependence of TMR, the local transport properties were measured for Ta $50{\AA} /Cu 200 {\AA}/Ta 50 {\AA}/Ni_{76}Fe_{24} 20 {\AA}/Cu 50 {\AA}/Mn_{75}Ir_{25} 100 {\AA}/Co_{71}Fe_{29} 40 {\AA}/Al-O$ junction with $d_{Al}= 8 {\AA} and P_{O2}{\times}t_{0X}/ = 8.4 {\times} 10^4$ at various temperatures. The current histogram statistically calculated from the electrical current image was well in accord with the fitting result considering the Gaussian distribution and Fowler-Nordheim equation. After annealing at $340^{\circ}C$, where the TMR ratio of the corresponding MTJ had the maximum value of 44%, the average barrier height increased to 1.12 eV and its standard deviation decreased to 0.1 eV. The increase of TMR ratio after annealing could be well explained by the enhancement of the average barrier height and the reduction of its fluctuation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.11
• /
• pp.1617-1626
• /
• 2012

The objective of this study was to evaluate the effects of adding essential oils to the diet of weaned pigs on performance, nutrient utilization, immune response and intestinal health. A total of 96 weaning pigs ($8.37{\pm}1.58$ kg) were allotted to one of three dietary treatments. The treatments consisted of an unsupplemented basal diet (negative control, NC) or similar diets supplemented with 0.01% of an essential oil product which contained 18% thymol and cinnamaldehyde (EOD) as well as a diet supplemented with 0.19% of an antibiotic mixture which provided 150 ppm chlortetracycline, 80 ppm colistin sulfate and 50 ppm kitasamycin (positive control, PC). Each treatment was provided to eight pens of pigs with four pigs per pen. Over the entire 35 d experiment, ADG and fecal score were improved (p<0.05) for pigs fed the PC and EOD compared with the NC. Dry matter and crude protein digestibility as well as lymphocyte proliferation for pigs fed the PC and EOD diets were increased significantly compared with NC (p<0.05). IGF-I levels in plasma were significantly increased (p<0.05) in pigs fed the PC diet compared with pigs fed the NC diet. Interleukin-6 concentration was lower (p<0.05) and the tumor necrosis factor-${\alpha}$ level was higher (p<0.05) in the plasma of pigs fed the EOD diet than the NC diet. Plasma total antioxidant capacity level increased (p<0.05) in pigs fed the EOD diet compared with pigs fed the NC. Villus height to crypt depth ratio in the jejunum was greater (p<0.05) in pigs fed the PC and EOD diets than the NC. The numbers of E. coli in the cecum, colon and rectum were reduced (p<0.05) in pigs fed the PC and EOD diets compared with the control. In the colon, the ratio of Lactobacilli to E. coli was increased (p<0.05) in pigs fed the EOD diet compared with NC diet. Total aerobe numbers in the rectum were decreased (p<0.05) in pigs fed the PC and EOD diets compared with the control. Collectively, these results indicate that blends of essential oils could be a candidate for use as an alternative to traditional antibiotics in weaning pig diets.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.11
• /
• pp.1555-1561
• /
• 2016

Shank skin color of Korean native chicken (KNC) shows large color variations. It varies from white, yellow, green, bluish or grey to black, whilst in the majority of European breeds the shanks are typically yellow-colored. Three shank skin color-related traits (i.e., lightness [$L^*$], redness [$a^*$], and yellowness [$b^*$]) were measured by a spectrophotometer in 585 progeny from 68 nuclear families in the KNC resource population. We performed genome scan linkage analysis to identify loci that affect quantitatively measured shank skin color traits in KNC. All these birds were genotyped with 167 DNA markers located throughout the 26 autosomes. The SOLAR program was used to conduct multipoint variance-component quantitative trait locus (QTL) analyses. We detected a major QTL that affects $b^*$ value (logarithm of odds [LOD] = 47.5, $p=1.60{\times}10^{-49}$) on GGA24 (GGA for Gallus gallus). At the same location, we also detected a QTL that influences $a^*$ value (LOD = 14.2, $p=6.14{\times}10^{-16}$). Additionally, beta-carotene dioxygenase 2 (BCDO2), the obvious positional candidate gene under the linkage peaks on GGA24, was investigated by the two association tests: i.e., measured genotype association (MGA) and quantitative transmission disequilibrium test (QTDT). Significant associations were detected between BCDO2 g.9367 A>C and $a^*$ ($P_{MGA}=1.69{\times}10^{-28}$; $P_{QTDT}=2.40{\times}10^{-25}$). The strongest associations were between BCDO2 g.9367 A>C and $b^*$ ($P_{MGA}=3.56{\times}10^{-66}$; $P_{QTDT}=1.68{\times}10^{-65}$). However, linkage analyses conditional on the single nucleotide polymorphism indicated that other functional variants should exist. Taken together, we demonstrate for the first time the linkage and association between the BCDO2 locus on GGA24 and quantitatively measured shank skin color traits in KNC.

• Korean Journal of Food Science and Technology
• /
• v.12 no.1
• /
• pp.45-52
• /
• 1980

The nylon (poly 6, 10) microcapsules containing ${\beta}-galactosidase$ were obtained by the interfacial polymerization of 1, 6-diaminohexane and sebacoyl chloride with ${\beta}-galactosidase$ from Escherichia coli. They were generally spherical and had a mean diameter of $80{\mu}$ with 45 % of the activity recovery. In particular, there was no transport hamper of lactose through the membrane of microcapsules. The characteristics of the microencapsulated enzyme were similar to those of soluble enzyme optimal pHs, $7.0{\sim}7.2$ for the soluble and $7.3{\sim}7.5$ for the microencapsulated ; optimal temperatures, $50^{\circ}C$ for both ; apparent $K_m,\;3.33{\times}10^{-4}(on ONPG),$ $2.86{\times}10^{-3}$ M(on lactose) for the soluble and $5.28{\times}10^{-4}$ (on ONPG), $4.25{\times}10^{-3}$ M (on lactose) for the microencapsulated ; activation energies, 8.94 for the soluble and 9.78 Kcal/mole for the microencapsulated enzyme. Using this microencapsulated ${\beta}-galactosidase$, hydrolyses of lactose and milk lactose were carried out and 80 % of 5 % lactose solution and 70 % of lactose in skim milk were hydrolyzed in 40 hr at $27^{\circ}C$. The reusability and operational stability showed that the remaining activity was 50 % of the original activity after 5 runs and 120 hr of total operating time at $27^{\circ}C$.

• Journal of Animal Science and Technology
• /
• v.48 no.6
• /
• pp.933-942
• /
• 2006

This experiment was carried out to investigate effects of honeybee venom treatment on the humoral immune response in pigs. Corresponding author : S. K. Cho, Dept. of Animal Sci. Chung-Buk National University, Kaesin-dong, Cheongju, 361-763, Korea. phone : 043-261-2551. E-mail : deercho@chungbuk.ac.kr To investigate effects of natural honeybee venom on the concentration of immunoglobulin G, A, and M, 20 piglets(LY×D) from 3 sows were allocated into two groups bee venom-treated group(10 piglets) and non-treated control(10 piglets). Natural honeybee venom was treated at 0, 3, 6 days after birth and the acupoints were Hai-men(ST-25), Du-kou(CV-8) and Jiao-chao(GV-1) points at 0, 3 days after birth and the regions of castration and tail amputation point at 6 days. Control group was injected 1㎖ of saline to the same site. Concentrations of IgG, A, and M were measured with immunoturbidimetric method at 0, 3, 7, 14, and 21 days after treatment. To investigate the effect of bee venom on the production of antibodies against hog cholera and atrophic rhinitis vaccines that were used as indicator antigens, 40 piglets(LYxD) from 5 sows were grouped as bee venom-treated group (20 piglets) and control group(20 piglets). Natural honeybee venom was treated at 0, 3days(castration, tail amputation) and 21days after birth. The acupoints were Hai-men(ST-25), Du-kou(CV-8) and Jiao-chao (GV-1) points at 0 day, the regions of castration and tail ampution at 3 days and Jiao-chao(GV-1) and Bai-hui(GV-20) points at 21days after birth(weaning). Control group was injected 1ml of saline to the same site. Atrophic rhinitis vaccine was injected twice at 24 and 44 days after birth and hog cholera vaccine was also injected twice at 44 and 64 days after birth. Antibody titers against Bordetella bronchiseptica and hog cholera virus were measured by using tube agglutination and ELISA tests at 24, 34, 44, 54 and 74 days after birth. Concentrations of IgG of treated group were 339.52, 366.48, 296.52, 242.06 and 219.06mg/dl at 0, 3, 7, 14 and 21 days after birth, respectively. In contrast, concentrations of IgG in control group were respectively 347.10, 334.14, 243.28, 205.18 and 191.58mg/dl during same periods with treated group. Concentrations of IgG at 0 day was not significantly different between the treated group and control group but treated group were significantly increased by 10.28% at 3 days after birth (P<0.02), 21.88% at 7 days after birth(P<0.01), 18.0% at 14 days after birth(P<0.07) and 14.3% at 21 days after birth(P<0.01). Concentrations of IgA and Ig M were not significantly different. Antibody titers against hog cholera virus were significantly increased by 57.0% at 24 days after birth(P<0.03), 74.6% at 34 days after birth (P<0.006), 48.6% at 44 days after birth(P<0.017), 45.0% at 54 days after birth(P<0.16) and 44.4% at 74 days after birth (P<0.006) in bee venom treated group in comparison with control group. Antibody titers against the Bordetella bronchiseptica was significantly increased in Beevenom treated group as 9.1% (P<0.32) at 24days, 39.7% (P<0.002) at 34days, 31.9% (P<0.02) at 44days, 33.4% (P<0.01) at 54days and 57.3% (P<0.007) at 74 days after birth when compared with those of control group pigs. Collecting together, the results in this study showed that immune responses were increased by treatment of natural honeybee venom to pigs. These results suggested that the treatment of bee venom could be used effectively for the increase of productivity in livestock industry.

• Journal of Korean Society on Water Environment
• /
• v.25 no.2
• /
• pp.288-294
• /
• 2009

Flow field-flow fractionation (Fl-FFF) device has been widely used to verify the size and molecular weight of various colloids and organics. The Fl-FFF, however, generally uses carrier solutions with only low to moderate ionic strengths to exclude the high affinity of materials to the membrane under high ionic strength conditions. Thus, materials existing in seawaters have not been accurately analysed based on the hydrodynamic size and molecular weight using current Fl-FFF techniques. The highest ionic strength tested was up to 0.1 M, while seawater ionic strength is about 0.6 M. The aim of this study is to accurately measure the hydrodynamic size of particles under carrier solutions close to seawater conditions with the Fl-FFF. By employing various operating conditions during the Fl-FFF analyses, it was demonstrated that the flow conditions, the concentration of surfactants, and stabilization times were key factors in acquiring compatible data. Results have shown that the cross flow was more influential factor than the channel flow. The concentration of the surfactant was to be at least 0.05% and the minimum 15 hr of stabilization was needed for accurate and reproducible data acquisition under seawater condition.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.12 no.1
• /
• pp.1-6
• /
• 2016

Characteristics of exhaust from chimney of electricity generator are analyzed based on CFD when Waveguide-Below-Cutoff (WBC) array is installed in order to achieve the certain level of electromagnetic pulse (EMP) shielding. The main purpose is prediction of average and maximum velocity of exhaust. The results reveal that: 1) When the specification of waveguide is given as 80-diameter, 400-length, and the gap of 20 mm, the shielding effectiveness (SE) is 140dB. The average and maximum velocity of exhaust in the chimney with WBC Array can be represented as exponential functions. 2) As the number of WBC increases, the velocity in the chimney dwindles. 3) Under the situation that WBC with 80 mm diameter is located at intervals of 20 mm, the average velocity can be approximated by $25.5344{\times}e^{(-0.0098{\times}N_{WBC})}$ with input velocity of 15 m/s. In addition, the determination coefficient is 0.915, which is sufficiently high.

• The Journal of Korean Society of Virology
• /
• v.29 no.3
• /
• pp.165-174
• /
• 1999

To investigate viral pathogenesis and in vivo efficacy of acyclovir (ACV) in mouse HSV-1 encephalitis models, female BALB/c mice aged 5 weeks were inoculated with strain F either intranasally (IN) or intracerebrally (IC). ACV-treatment by intraperitomeal injection with 0, 5, 10 and 25 mg/kg b.i.d. for 6 days was commenced 1 h after infection. Body weight and signs of clinical disease were noted daily up to 2 weeks. $ED_{50}$ of ACV in IN infection was <5 mg/kg and 14.1 mg/kg in IC infection. Tissues of central nervous system were collected from 2 mice per group everyday up to 5 day p.i. and the virus titers were measured. In IN infection model, high titers in eyes and trigeminal nerves were observed. ACV-treatment showed significant reduction of the titers in all the isolated. In IC infection model, cerebrum, cerebellum and brain stem showed high virus titers. ACV-treatment showed less significant reduction of virus titers than that in IN infection model. Reactivation of explanted trigeminal nerves from mice 30 day p.i. was monitored. In all of ACV treated mice reactivation was observed, i.e. even the highest dose of ACV did not inhibit the establishment of viral latency.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.1
• /
• pp.176-181
• /
• 2009

In this work, a new type of DSCs based on nanoporous FTO structure is being developed for research aimed at low-cost high-efficiency solar cell application. The nanoporous FTO materials have been prepared through the sol-gel combustion method followed by thermal treatment at $450{\sim}850[^{\circ}C]$. The properties of the nanoporous FTO materials were investigated by IR spectra, BET and TEM analyses, and the photovoltaic performance of the prepared DSCs were examined. It can be seen from the result that the nanoporous FTO exhibited good transparent conductive properties, well suited for DSCs application.