• KIEE International Transactions on Electrophysics and Applications
• /
• v.5C no.3
• /
• pp.102-110
• /
• 2005

Piezoelectric transformers(PT) are expected to be small, thin and highly efficient, and which are attractive as a transformer with high power density for step down voltage. For these reasons, we have attempted to develop a step-down PT for the miniaturized adaptor. We propose a PT, operating in thickness extensional vibration mode for step-down voltage. This PT consists of a multi-layered construction in the thickness direction. In order to develop the step-down PT of 10 W class and turn ratio of 0.1 with high efficiency and miniaturization, the piezoelectric ceramics and PT designs are estimated with a variety of characteristics. The basic composition of piezoelectric ceramics consists of ternary yPb(Zr$_{x}$Ti$_{1-x}$)O$_{3}$-(1-y)Pb(Mn$_{1/3}$Nb1$_{1/3}$Sb$_{1/3}$)O$_{3}$. In the piezoelectric characteristics evaluations, at y=0.95 and x=0.505, the electromechanical coupling factor(K$_{p}$) is 58$\%$, piezoelectric strain constant(d$_{33}$) is 270 pC/N, mechanical quality factor(Qr$_{m}$) is 1520, permittivity($\varepsilon$/ 0) is 1500, and Curie temperature is 350 $^{\circ}C$. At y = 0.90 and x = 0.500, kp is 56$\%$, d33 is 250 pC/N, Q$_{m}$ is 1820, $\varepsilon$$_{33}$$^{T}$/$\varepsilon$$_{0}$ is 1120, and Curie temperature is 290 $^{\circ}C$. It shows the excellent properties at morphotropic phase boundary regions. PZT-PMNS ceramic may be available for high power piezoelectric devices such as PTs. The design of step-down PTs for adaptor proposes a multi-layer structure to overcome some structural defects of conventional PTs. In order to design PTs and analyze their performances, the finite element analysis and equivalent circuit analysis method are applied. The maximum peak of gain G as a first mode for thickness extensional vibration occurs near 0.85 MHz at load resistance of 10 .The peak of second mode at 1.7 MHz is 0.12 and the efficiency is 92$\%$.

• Journal of Nutrition and Health
• /
• v.50 no.3
• /
• pp.236-245
• /
• 2017

Purpose: The aim of this study was to assess the effects of guava leaf extract (GLE) supplementation on antioxidant enzyme activity and expression of endothelial nitric oxide synthase (eNOS) mRNA in ovariectomized rats. Methods: All animals were randomly assigned to four groups (n = 7 for each group): non-ovariectomized control (Sham), the ovariectomized control (OVX), ovariectomy + 150 mg/kg b.w. of GLE ($OVX{\cdot}GL$), and ovariectomy + 300 mg/kg b.w. of GLE ($OVX{\cdot}GH$). Treatment groups were administered GLE for 8 weeks every day. Results: Body weight gain was significantly reduced in the $OVX{\cdot}GL$ group compared with the OVX group (p < 0.05). The level of serum $17{\beta}$-estradiol (E2) was significantly lower in the OVX groups than the Sham group (p < 0.05). Serum triglyceride (TG) and HDL-cholesterol levels were not significantly different between all groups. However, serum total cholesterol (TC) level was significantly reduced in the $OVX{\cdot}GH$ group compared with the OVX group (p < 0.05). Serum free fatty acid (FFA) level and liver TG level were significantly reduced in both $OVX{\cdot}GL$ and $OVX{\cdot}GH$ groups compared with the OVX group (p < 0.05). Furthermore, serum glutathione peroxidase (GPx) activity was significantly elevated in the GLE groups (p < 0.05). The mRNA expression level of GPx was not affected by ovariectomy. However, administration of GLE resulted in significantly increased nuclear factor erythroid 2-related factor (Nrf2) and catalase (CAT) mRNA expression levels in the liver (p < 0.05). In addition, liver nitric oxide (NO) level was significantly reduced in the $OVX{\cdot}GH$ group compared with the OVX group (p < 0.05). Expression level of endothelial nitric oxide synthase (eNOS) was significantly elevated in the $OVX{\cdot}GH$ group compared with the OVX group (p < 0.05). Conclusion: These results suggest that GLE could have protective effects in OVX rats by stimulating eNOS expression and improving the antioxidant defense system.

• Animal Bioscience
• /
• v.34 no.7
• /
• pp.1169-1180
• /
• 2021

Objective: This research aimed to study the effects of Artemisia argyi flavonoids (AAF) supplemented in diets on the growth performance and immune function of broiler chickens challenged with lipopolysaccharide (LPS). Methods: A total of one hundred and ninety-two 1-d-old broiler chicks were assigned into 4 treatment groups, which were, respectively, fed a basal diet (control), fed a diet with 750 mg/kg AAF, fed a basal diet, and challenged with LPS, fed a diet with 750 mg/kg AAF, and challenged with LPS. Each treatment had six pens with 8 chicks per pen. On days 14, 16, 18, 20 (stress phase I) and 28, 30, 32, 34 (stress phase II), broilers were injected with LPS (500 ㎍/kg body weight) or an equivalent amount of saline. Results: The results demonstrated that dietary AAF significantly improved the body weight (d 21) and alleviated the decrease of average daily gain in broilers challenged with LPS on d 21 and d 35 (p<0.05). Dietary AAF increased bursa fabricius index, and dramatically attenuated the elevation of spleen index caused by LPS on d 35 (p<0.05). Furthermore, serum interleukin-6 (IL-6) concentration decreased with AAF supplementation on d 21 (p<0.05). Diet treatment and LPS challenge exhibited a significant interaction for the concentration of IL-1β (d 21) and IL-6 (d 35) in serum (p<0.05). Additionally, AAF supplementation mitigated the increase of IL-1β, IL-6 in liver and spleen induced by LPS on d 21 and 35 (p<0.05). This study also showed that AAF supplementation significantly reduced the expression of IL-1β (d 21) and nuclear transcription factor kappa-B p65 (d 21 and 35) in liver (p<0.05), and dietary AAF and LPS treatment exhibited significant interaction for the gene expression of IL-6 (d 21), toll like receptor 4 (d 35) and myeloid differentiation factor 88 (d 35) in spleen (p<0.05). Conclusion: In conclusion, AAF could be used as a potential natural immunomodulator to improve growth performance and alleviate immune stress in broilers challenged with LPS.

• Journal of Navigation and Port Research
• /
• v.46 no.3
• /
• pp.216-226
• /
• 2022

The industry trends of major global shipping and ports in the world are changing rapidly because of the spread of COVID-19, resulting in the reorganization of GVCs by global companies, and strengthening of environmental regulations by IMO. Based on these environmental changes, Busan Port was ranked 5th in the global container port rankings in 2013. However, since the outbreak of COVID-19, Busan Port's global container port ranking in 2020 fell to 7th, behind Qingdao Port. In the post-Corona era, for Busan Port to compete with global container ports and gain a competitive edge in the port, it is necessary to accurately identify the competitive factors of Busan Port and establish a comprehensive policy. Thus, the purpose of this study was to analyze how the competitive factors of Busan Port have changed in the selection of ports by current global shipping companies, compared to the first study conducted in 2005. Additionally, a comprehensive policy plan was established by identifying factors impacting the frequency of future calls as well as the growth potential of Busan Port, through a stepwise multiple regression analysis. As a result of the analysis, it was found that the call preference and growth potential of Busan Port in the post-Corona era are most affected by 'port facilities'. And it was found that the calls frequency in the future is most impacted by 'the geopolitical location' factor.

• Animal Bioscience
• /
• v.35 no.3
• /
• pp.461-474
• /
• 2022

Objective: This experiment investigated the effects of supplementing vitamin D₃-fortified sow and progeny diets with 25(OH)D₃ on growth performance, carcass characteristics, immunity, and pork meat quality. Methods: The present study involved the assessment of supplementing the diet of sows and their progeny with or without 25 (OH)D₃ in a 2×2 factorial arrangement on the performance and production characteristics of wean-finish pigs. Forty-eight multiparous sows were assigned to a basal diet containing 2000 IU/kg vitamin D₃ and supplemented without (CON) or with (TRT) 50 ㎍/kg 25 (OH)D₃. At weaning, a total of 80 pigs each from CON and TRT sows were allocated to weaning and growing-finishing basal diets fortified with 2,500 and 1,750 IU/kg vitamin D₃ respectively and supplemented without or with 50 ㎍/kg 25(OH)D₃. Results: Sows fed 25(OH)D₃-supplemented diets improved pre-weaning growth rate of nursing piglets. A significant sow and pig weaning diet effect was observed for growth rate and feed efficiency (p<0.05) during days 1 to 42 post-weaning. Pigs consuming 25(OH)D₃-supplemented diets gained weight faster (p = 0.016), ate more (p = 0.044) and tended to convert feed to gain more efficiently (p = 0.088) than those fed CON diet between days 98 and 140 post-weaning. Supplemental 25(OH)D₃ improved water holding capacity and reduced drip loss of pork meat, increased serum 25(OH)D₃ level, produced higher interleukin-1 and lower interleukin-6 concentrations in blood circulation, downregulated myostatin (MSTN) and upregulated myogenic differentiation (MYOD) and myogenic factor 5 (MYF5) gene expressions (p<0.05). Conclusion: Supplementing vitamin D₃-fortified sow and wean-finish pig diets with 50 ㎍/kg 25(OH)D₃ significantly improved production performance suggesting their current dietary vitamin D₃ levels are insufficient. In fulfilling the total need for vitamin D, it is strongly recommended to add 50 ㎍/kg 25(OH)D₃ "on top" to practical vitamin D₃-fortified sow and wean-finish pig diets deployed under commercial conditions.

• Animal Bioscience
• /
• v.36 no.5
• /
• pp.761-767
• /
• 2023

Objective: The objective of this study was to determine whether dietary supplementation with a functional fatty acid blend (FA) that contains 31.4% butyric acid and 4.99% medium-chain FA improve growth performance, antioxidant capacity, immunity status, and anti-inflammatory ability in weaned piglets. Methods: One hundred and forty-four healthy piglets (Duroc×Landrace×Yorkshire) with an average body weight (BW) of 7.98±3.43 kg were randomly divided into three groups with six replicate pens and eight piglets per pen: Normal control (NC): a corn-soybean basal diet; FA1: a basal diet supplemented with 1,000 mg/kg of a functional FA; FA2: a basal diet supplemented with 2,000 mg/kg of a functional FA. The experiment lasted for 28 d. On d 14 and 28, one piglet in each pen from NC and FA2 groups was randomly selected for antioxidative index and immunoglobulins. On d 28, one piglet in each pen from NC and FA2 groups was randomly selected for intestinal morphology and inflammatory factor. Results: We observed that FA supplementation linearly increased (p<0.05) average daily gain and the final BW. There was higher (p<0.05) catalase on d 14, and immunoglobulin (Ig) A and IgM on d 28 in piglets supplemented with FA2 than in the NC group. Moreover, dietary FA2 reduced (p<0.05) crypt depth of ileum in piglets. The concentrations of tumor necrosis factor-α, interleukin (IL)-1β, IL-8, and IL-10 in jejunum were lower (p<0.05) in the FA2 group compared with the NC group. Conclusion: Therefore, the overall results suggests that the FA may help to improve gut health, antioxidant status, and immune parameters resulting in the improvement of growth performance.

• Animal Bioscience
• /
• v.36 no.5
• /
• pp.753-760
• /
• 2023

Objective: This study aimed to investigate the effects of essential oil coated with glycerol monolaurate (GML) on the growth performance, intestinal morphology, and serum profiles of weaned piglets. Methods: A total of 144 weaned piglets (Duroc×[Landrace×Yorkshire], average weight 8.07±3.33 kg) were randomly assigned to three groups with six replicate pens and eight piglets per pen: i) CON: a corn-soybean basal diet; ii) LEG: with 1,000 mg/kg essential oil coated with GML; and iii) HEG: with 2,000 mg/kg essential oil coated with GML. Results: Results showed that average daily gain was increased (p<0.05) linearly by essential oil coated with GML supplementation on day 14 to 28 and day 0 to 28 compared with the CON group. Dietary supplementation with HEG increased (p<0.05) total antioxidant capacity and catalase activity on day 14, and immunoglobulin A (IgA) and IgM concentration on day 28 and tended to increase IgG on day 28. In addition, the crypt depth in the jejunum was reduced (p<0.05), and villus height and villus height/crypt depth in the ileum were increased (p<0.05) in the HEG group compared with the CON group. Moreover, lower (p<0.05) concentrations of tumor necrosis factor-α, interferon-γ, interleukin-1β (IL-1β), IL-8, and IL-10 were observed in the jejunum of piglets supplemented with HEG compared with the CON group. In addition, dietary HEG tended to decrease IL-6 level in the jejunum of piglets compared with the CON group. Conclusion: Dietary essential oil coated with GML can improve growth performance of weaned piglets. Moreover, supplementing 2,000 mg/kg essential oil coated with GML was demonstrated to improve antioxidant ability, and intestinal morphology, and reduce jejunal inflammatory factor levels.

• Korean Journal of Poultry Science
• /
• v.50 no.4
• /
• pp.193-202
• /
• 2023

Influenza IAVs are encapsulated negative-strand RNA viruses that infect many bird species' respiratory systems and can spread to other animals, including humans. This work reanalyzed previous microarray datasets to identify common and specific differentially expressed genes (DEGs) in chickens, as well as their biological activities. There were 760 and 405 DEGs detected in HPAIV and LPAIV-infected chicken cells, respectively. HPAIV and LPAIV have 670 and 315 DEGs, respectively, with both viruses sharing 90 DEGs. Because of HPAIV infection, numerous genes were implicated in a fundamental biological function of the cell cycle, according to the functional annotation of DEGs. Of the targeted genes, expressions of CDC Like Kinase 3 (CLK3), Nucleic Acid Binding Protein 1 (NABP1), Interferon-Inducible Protein 6 (IFI6), PIN2 (TERF1) Interacting Telomerase Inhibitor 1 (PINX1), and Cellular Communication Network Factor 4 (WISP1) were altered in DF-1 cells treated with polyinosinic:polycytidylic acid (PIC), a toll-like receptor 3 (TLR3) ligand, suggesting that transcription of these genes be controlled by TLR3 signaling. To gain a better understanding of the pathophysiology of AIVs in chickens, it is crucial to focus more research on unraveling the mechanisms through which AIV infections may manipulate host responses during the infection process. Insights into these mechanisms could facilitate the development of novel therapeutic strategies.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.10
• /
• pp.1477-1483
• /
• 2014

This study investigated the anti-obesity effects of African mango (Irvingia gabonesis, IGOB $131^{TM}$) extract in leptin-deficient obese mice. Experimental groups were treated with two different doses of IGOB $131^{TM}$ (1% and 2% in each AIN93G supplement) for 8 weeks. Treatment of obese mice with both low and high dose of IGOB $131^{TM}$ significantly reduced body weight gain by 10.9% and 13.3%, respectively, compared to control obese mice. Subcutaneous adipose tissue weight of mice was significantly reduced by 18% by low-dose and 23% by high-dose supplementation. This result was supported by micro-CT analysis around the abdominal regions of mice, indicating that the adipose tissue area and volume were significantly reduced by treatment with IGOB $131^{TM}$. Serum levels of triglycerides in the low- and high-dose groups were reduced by 36.5% and 43.8%, respectively, upon treatment with IGOB $131^{TM}$, whereas total cholesterol levels were reduced by 31.8% and 35.4%. Interestingly, the serum LDL level decreased upon treatment with IGOB $131^{TM}$ while the serum level of HDL dramatically increased upon high-dose treatment with IGOB $131^{TM}$, resulting in a significant reduction in the LDL to HDL ratio of 59.2%. These results were supported by the expression levels of enzymes and proteins related to lipid metabolism assessed by real-time PCR. There was a significant increase of in adiponectin expression as well as significant decreases in the expression of FAS, LPL, and lipid regulatory transcription factors such as PPAR-${\gamma}$, C/EBP, and SREBP upon both low- and high-dose IGOB $131^{TM}$ treatment. However, there was no statistical difference between low- and high-dose treatments. These results suggest that IGOB $131^{TM}$ is able to regulate the serum lipid profiles by reducing triglyceride and increasing HDL levels as well as regulate expression of lipid metabolic factors, resulting in reduction of a weight gain in leptin-deficient obese mice.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.9
• /
• pp.432-439
• /
• 2020

To improve the relatively low economic efficiency of the Korean native pig, the Korean National Institute of Animal Science developed a novel pig breed, the Woori black pig (W), by crossing Korean native and Duroc (D) pigs. This study was conducted to evaluate the effects of W as a terminal sire on growth performance, body shape, and retail cut yield of crossbred pigs. By using a completely randomized design, 32 crossbred pigs were allotted to one of two treatment groups based on terminal sire. The two groups were LYD [(Landrace × Yorkshire) × D sire] and LYW [(Landrace × Yorkshire) × W sire]. The experimental assessments were conducted over 53 days. The terminal sire breed had no significant effect on body weight (BW) at d 53, or on BW gain, average daily gain, or days to reach a 90 kg body weight. Moreover, there were no significant differences in body length, body height, or chest depth between the two groups. However, there was a significant difference (p < 0.05) in backfat thickness between the LYD (17.29 mm) and LYW (18.96 mm) groups. Loin yield of crossbred pigs in the LYW group (13.11%) was significantly lower (p < 0.05) than that in the LYD group (13.85%). By contrast, the Boston butt yield was significantly higher (p < 0.05) in the LYW group (8.99%) than in the LYD group (8.21%). In conclusion, these results suggest crossbred pigs sired by a Woori black pig had growth performance, shape, and retail cut yield (except loin yield) Ed. Note: I assume the lower loin yield is a negative factor so I included this wording. similar to those sired by a Duroc pig. The results showed no overall negative effect Ed. Note: I assume the lower loin yield is a negative factor so I used this wording. on crossbred offspring, indicating the suitability of the Woori black pig as a terminal sire.