• 정보통신설비학회논문지
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• 제2권4호
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• pp.42-51
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• 2003

본 논문에서는 무선 LAM 시스템에서 전력증폭기의 위상왜곡에 따른 출력 스펙트럼의 관계에 대해 분석하고자 하였으며, 이를 위해 전력증폭기의 ACPR. 특성과 OFDM방식의 고려사항을 고찰하였다. 또한, OFDM 변조방식과 전력증폭기의 비선형성과의 관계를 알기위해 최대. 54Mbps의 전송속도를 갖는 IEEE 802.11a 규격의 OFDM 변조부와 송신부를 시뮬레이션하였다. 전력증폭기의 비선형 특성은 AM-to-AM과 AM-to-PM으로 모델링 하였으며, 구성된 입력 신호원을 전력증폭기에 인가하여 위상왜곡에 따른 출력 스펙트럼 특성을 분석하였다. 출력 스펙트럼 분석결과 위상왜곡이 증가할수록 전력 증폭기의 AM-to-PM 특성이 $5^{\circ}$일 때 P1dB에서의 출력 스펙트럼은 요구 스펙트럼을 만족하였지만, $10^{\circ}$에서부터 $20^{\circ}$까지의 위상왜곡에서는 요구 스펙트럼을 만족하지 못함을 확인할 수 있었다. 또한, 전력증폭기의 비선형 특성으로 인해 생성되는 주파수 재성장으로 인한 전력증폭기의 출력 스펙트럼은 P1dB에서 만족하지 않는다. 따라서, AM-to-PM 왜곡 정도에 따라 back-off값이 요구되며, OFDM을 이용한 변조부의 경우 더 적은 back-off값이 요구됨을 알 수 있었다.

• 한국축산식품학회지
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• 제33권5호
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• pp.587-594
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• 2013

Egg consumption has been limited to avoid cardiovascular diseases such as atherosclerosis and hyperlipidemia, because the yolk contains high levels of cholesterol. This study was conducted to evaluate the effect of the water-soluble component of egg-yolk on the growth efficiency, immune modulation, and changes in serum lipid levels in BALB/c mice. A total 5 wk old 120 BALB/c male mice were divided into 4 groups and were fed 0, 2, 10, and 20 mg/d water-soluble egg yolk extract (WSEYE) for 5 wk. Water-soluble egg yolk extract (WSEYE) uptake resulted in a significant reduction in daily weight gain and feed efficiency rate (FER). The mouse groups treated with 2 and 20 mg/d WSEYE showed a significant increase in populations of monocytes at the third wk and B-lymphocyte activity at the fifth wk. In addition, WSEYE uptake did not influence serum immunoglobulin E levels. In serum lipid-profile studies, treatment of WSEYE did not alter total cholesterol and low-density lipoprotein levels; however, blood triglyceride levels were significantly diminished in mice treated with 2 mg/d at the third wk (p<0.05), and the level of high-density lipoprotein was significantly increased in the mice group treated with 2 and 10 mg/d WSEYE after 5 wk (p<0.05). Taken together, the data demonstrate the beneficial effects of WSEYE in the diet on immune modulation and serum lipid profiles in mouse models; therefore, this study suggests that ingestion of water-soluble fraction of egg yolk might not be related to the increased risk of heart disease, but can be an excellent candidate for maintaining health.

• 한국가축번식학회지
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• 제21권4호
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• pp.325-333
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• 1997

Recent evidence indicates that growth factors modulate response of mammary epithelial cells to environmental stress. The objective of this study was to examine the cellular and biochemical responses of mammary tissue to environmental stress caused by artificial mastitis. For experimental a, pp.oach, toxins of most mastitis causing organisms(Staph. aureus or Strep. agalactiae) and heat stress(42$^{\circ}C$) were artificially exposed to mammary tissue. Effects of these environmental stresses on cell growth, cell death and heat shock protein synthesis were examined. Lactating mammary tissure were cultured under basal medium(DMEM) su, pp.emented with insulin(10$\mu\textrm{g}$/ml) and aldosterone(1$\mu\textrm{g}$/ml). All treatment groups in heat stress at 42$^{\circ}C$ incubation significantly decreased DNA synthesis rates in comparison with those at 39$^{\circ}C$(P<0.05), however, these decreased DNAa synthesis rates were recovered by addition of adenosine(10$\mu$M) and IGFI(10ng/ml). Similar results were obtained when tissue growth rates were measured by DNA content/tissue. Strep. agalactiae toxin did not significantly decreased DNA content/tissue in comparison with no treatment of bacterial toxin with or without heat stress, however, tended to decrease DNA contents/tissue without heat stress. In the fluorography analysis, heat stress(42$^{\circ}C$ incubation) slightly increased 35S-methoionine labelled 70kd protein synthesis. These results indicate that environmental stress caused by artificial mastitis slightly decreased mammary growth or mammary size, however, these results could be recovered by addition of adenosine and IGF-I.

• Journal of Microbiology and Biotechnology
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• 제9권1호
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• pp.113-118
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• 1999

The insulin-like growth factor (IGF) is found in all vertebrates and its type-II molecule is regarded as a fundamental embryonic growth factor during development. We have firstly identified, in this study, a cDNA clone corresponding to IGF-II (flIGF-II) from the adult brain of the teleost, Paralichthys olivaceus. We also examined the tissue expression of flIGF-II in several adult tissues by RT-PCR. The flIGF-II cDNA contained a complete ORF consisting of 215 amino acids and one stop codon. Its molecular characteristics appear to be similar to the previously identified IGF-II molecules, in which a common primary structure exhibiting B, C, A, D, and E domains is evidently observed. This cDNA clone seems to be cleaved at $Ala_{52}$ for the $NH_2$-end signal peptide and appears to produce a 98 amino acid-long E-peptide from the $Arg^{118}$. The functional B-D domain regions, therefore, include 65 amino acids and is able to encode a 7.4-kDa protein. The most prominent structural difference between IGF-I and IGF-II was that the D domain of IGF-II exhibits a two-codon-deleted pattern compared to the 8 amino acid-containing IGF-I. The insulin family signature in the A domain and six cysteins forming three disulfide bridges between the B and A domains were evolutionary-conserved from teleosts to mammalian IGF-II. Interestingly, the E-peptide region appears to provide a distinct hallmark between teleosts in amino acid composition. The flIGF-II shows 85.1% of sequence identity to salmon and trout, 90.6% to tilapia, and 98.4% to perch in amino acid level. In tissue expressions of IGF-II, it is very likely that flIGF-II has a significant expression in the adult brain. However, liver seems to be the main source for IGF-II production, and relatively low signals were observed in the adult muscle and kidney. Taken together, it would be concluded that the functional region for IGF-II mRNA is highly similar in phylogeny and is evolutionary, conserved as a mediator for the growth of vertebrates.

• Journal of Animal Science and Technology
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• 제64권6호
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• pp.1092-1104
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• 2022

Using antibiotics as growth promoter has been banned in poultry feed industry, thus various researchers try to seek an alternative to replace the growth-promoting antibiotics. In this study, we aimed to evaluate the growth performance via intestinal nutrient utilization and cecal microbial composition of broiler after dietary supplementation with most commonly using antibiotics, zinc bacitracin, and sophorolipid. A total of 180 1-day-old chicks were randomly assigned, and dietary treatment was as follow: CON, basal diet; ZB, 100 ppm of zinc bacitracin supplemented diet; and SPL, 250 ppm of sophorolipid supplemented diet. Their growth performance was evaluated and the samples of blood, small intestine, and ileal and cecal digesta were collected for biochemical, histological, and genomic analyses. The body weight and average daily gain of 7-day-old chicks were higher in ZB and those in overall experimental period were improved by ZB and SPL supplementation (p < 0.05). Their intestinal characteristics were not affected by dietary treatments in duodenum and ileum. Nonetheless, villus height was increased by SPL supplementation in jejunum (p < 0.05). Moreover, dietary SPL supplementation could down-regulate the expression level of pro-inflammatory cytokine, IL-1β (p < 0.05). mRNA levels of lipid and protein transporters did not differ among the treatments, however, relative expression levels of carbohydrate transporters, GLUT2 and SGLT1 were increased in broiler chicken's jejumum fed zinc bacitracin and sophorolipid supplemented diets (p < 0.05). Dietary zinc bacitracin supplementation could increase the population of Firmicutes in phylum level, and the portion of Turiciacter in genus level. On the other hands, the portion of Faecalibacterium was increased by dietary SPL supplementation compared to the other treatments. Our findings suggest that SPL supplementation improves growth performance through enhanced carbohydrate utilization capacity via improvement of gut morphological status and modulation of the cecal microbial population of broilers.

• Journal of Microbiology and Biotechnology
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• 제33권10호
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• pp.1390-1401
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• 2023

In this study, a 12-week feeding experiment was conducted to characterize the effects of exogenous α-amylase on the growth, feed utilization, digestibility, plasma α-amylase activity, feed degradation rate, and fecal particle size of olive flounder (Paralichthys olivaceus). Diet was supplemented with 0 (AA₀; control), 100 (AA₁₀₀), 200 (AA₂₀₀), or 400 (AA₄₀₀) mg/kg of α-amylase, respectively. Fish (273.1 ± 2.3 g) were stocked into 12 tanks (25 fish/1,000-L tank) and 3 tanks were randomly selected for each diet group. As a result, α-amylase was found to have no significant effects (p ≥ 0.05) on the growth, feed utilization parameters, and whole-body proximate compositions. α-Amylase-treated fish exhibited only a significant increase in the apparent digestibility coefficient of carbohydrates compared to the controls. In addition, in vitro analyses revealed that α-amylase dose-dependently increased (p < 0.05) the feed degradation rate, while photographs of the intestinal content after 2, 4, and 8 h of feeding demonstrated an improved degradation rate in the α-amylase-treated groups. Plasma α-amylase content was higher in the AA₂₀₀ and AA₄₀₀ groups, whereas the control group produced significantly larger-sized fecal particles (90% size class) than these two groups. In the intestine, no changes were observed in the expression levels of the immune-related TNF-α, IL-1β, IL-2, immunoglobulin-M, HSP-70, lysozyme, and amylase alpha-2A. However, growth-related genes IGF-1, IGF-2, TGF-β3, and growth hormone genes were upregulated in muscle tissues. Collectively, exogenous α-amylase has positive roles in the modulation of the digestibility coefficient, blood α-amylase concentration, growth-related gene expression, and diet degradation for improved digestion in olive flounder.

• Journal of Animal Science and Technology
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• 제65권4호
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• pp.856-864
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• 2023

There are a variety of microorganisms in the animal intestine, and it has been known that they play important roles in the host such as suppression of potentially pathogenic microorganisms, modulation of the gut immunity. In addition, the gut microbiota and the livestock growth performance have long been known to be related. Therefore, we evaluated the interrelation between the growth performance and the gut microbiome of the pigs from 3 different farms, with pigs of varied ages ready to be supplied to the market. When pigs reached average market weight of 118 kg, the average age of pigs in three different farms were < 180 days, about 190 days, and > 200 days, respectively. Fecal samples were collected from pigs of age of 70 days, 100 days, 130 days, and 160 days. The output data of the 16S rRNA gene sequencing by the Illumina Miseq platform was filtered and analyzed using Quantitative Insights into Microbial Ecology (QIIME)2, and the statistical analysis was performed using Statistical Analysis of Metagenomic Profiles (STAMP). The results of this study showed that the gut microbial communities shifted as pigs aged along with significant difference in the relative abundance of different phyla and genera in different age groups of pigs from each farm. Even though, there was no statistical differences among groups in terms of Chao1, the number of observed operational taxonomic units (OTUs), and the Shannon index, our results showed higher abundances of Bifidobacterium, Clostridium and Lactobacillus in the feces of pigs with rapid growth rate. These results will help us to elucidate important gut microbiota that can affect the growth performance of pigs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.617-624
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• 2007

Insulin-like growth factor(IGF) is the most abundant growth factor in bone matrix. Recent studies have shown that it can sensitize apoptotic cell death of osteoblasts. Thus, this study investigated whether IGF-II aggravates irradiation-induced cell death of osteoblasts. Cultured MC3T3 osteoblasts were irradiated and IGF-II was added at the concentration of 50 ng/ml immediately after the irradiation. Cell viability was measured by MTT assay. Changes in cell death and cell cycle were analyzed by flow cytometry. The expression of proapoptotic gene bax and antiapoptotic gene bcl-2 was quantified by real time RT-PCR and Western blot. A dose of 30 Gy caused G2/M arrest and increased cell death through both necrosis and apoptosis, while irradiation from 4 to 10 Gy little affected cell cycle and death. IGF-II treatment reduced cell viability without stimulating cell proliferation and changing cell cycle. Combined treatment of IGF-II with irradiation decreased cell viability and proliferation and increased cell death along with G2/M arrest. These effects were not different from those of irradiation only. At transcriptional and protein levels, IGF-II treatment did not affect bax and bcl-2 expression, whereas irradiation increased the expression ofbax without changes in bcl-2. IGF-II in combination with irradiation showed similar findings. These results suggest that IGF-II could modulate apoptotic cell death through mechanisms other than an imbalance between bax and bcl-2 gene expression, although its effect was overridden by irradiation.

• 농업생명과학연구
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• 제46권6호
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• pp.157-163
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• 2012

새송이버섯(Pleurotus eryngii)은 인기 있는 식용버섯 중의 하나로서 항산화, 항암 또는 면역조절 기능 등의 인체에 유익한 생리활성 기능을 지닌다. 본 연구에서는 새송이버섯 균사체 배양 시 커피음료 생산과정으로부터 폐기되는 커피박(spent coffee ground: SCG) 첨가에 의한 균사체의 생장과 기능성의 변화를 조사하였다. 그 결과, SCG(1-10%, w/v) 첨가 시 생장속도가 상당히 증가하는 경향을 나타내었다. 특히 1% SCG 첨가 시 무첨가에 비해 건조중량이 2.5배 증가함으로써 SCG가 탁월한 새송이버섯 균사체의 생장촉진제 기능이 제시되었다. SCG 첨가에 의하여 균사체의 polysaccharide 함량은 변화가 없었으나 polyphenol량 및 항산화능의 증대를 확인할 수 있었다.

• Animal Bioscience
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• 제35권6호
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• pp.869-883
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• 2022

Objective: The aim of study was to investigate the effects of in-feed supplementation of Bacillus amyloliquefaciens (BA) and Saccharomyces cerevisiae (SC) on growth performance, gut integrity, and microbiota modulations in red-feathered native chickens (RFCs). Methods: A total of 18,000 RFCs in a commercial farm were evenly assigned into two dietary treatments (control diet; 0.05% BA and 0.05% SC) by randomization and raised for 11 weeks in two separate houses. Fifty RFCs in each group were randomly selected and raised in the original house with the partition for performance evaluations at the age of 9 and 11 weeks. Six non-partitioned RFCs per group were randomly selected for analyses of intestinal architecture and 16S rRNA metagenomics. Results: Feeding BA and SC increased the body weight and body weight gain, significantly at the age of 11 weeks (p<0.05). The villus height/crypt ratio in the small intestines and Firmicutes to Bacteroidetes ratio were also notably increased (p<0.05). The supplementation did not disturb the microbial community structure but promote the featured microbial shifts characterized by the significant increments of Bernesiella, Prevotellaceae_NK3B31_group, and Butyrucimonas, following remarkable decrements of Bacteroides, Rikenellaceae_RC9_gut_group, and Succinatimonas in RFCs with growth benefits. Besides, functional pathways of peptidoglycan biosynthesis, nucleotide excision repair, glycolysis/gluconeogenesis, and aminoacyl transfer ribonucleic acid (tRNA) biosynthesis were significantly promoted (p<0.05). Conclusion: In-feed supplementation of BA and SC enhanced the growth performance, improved mucosal architectures in small intestines, and modulated the cecal microbiota and metabolic pathways in RFCs.