• 한국어병학회지
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• 제7권1호
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• pp.37-46
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• 1994

서해안 일원의 가온 양만장 사육조로부터 분리한 E. tarda균에 대한 약제내성검사 및 내성균의 내성인자 전달 시험을 실시하였다. 공시한 항생제에 대한 내성률은 LM, PM, SD, SF 등에는 100%, AP, CH, SM, OT 및 CP 등에는 89% 이상, OA 및 KM에는 70% 정도 그리고 AK, GM 및 EF 등에는 30% 이하의 내성률을 보였으며, 이와같은 내성률은 각 양만장에서 분리한 균주간에 차이를 보이지 않았다. 내성유형은 총 34유형으로 모든 분리균주가 8~14제의 다제내성을 보였으며, 그 중 LM PM SD SF CP CH SM OT AP OA KM(22주, 21.4%) 및 LM PM SD SF CP CH SM OT AP OA(12주, 11.7%) 유형등이 고빈도로 출현하였다. 내성균의 내성인자 전달유형은 총 55형으로 단제에서 13제까지의 다양한 내성인자가 전달되었는데, 그 중 LM PM SD SF CP CH SM OT AP OA(10주. 10%), LM PM SD SF CP CH SM OT AP OA KM(7주, 7%) 및 LM PM SD SF CP CH AP OA(7주, 7%) 등의 다제내성유형이 고빈도의 전달률을 보였으며, 약재별로는 GM, EF 및 AK 등에는 저빈도(0~20%), OT, SM, KM 및 OA 등에는 중등도(49~62%), AP, PM, LM, SF, CP, CH 및 SD 등에는 고빈도(71~94%)로 내성인자를 전달하였다.

• 대한화학회지
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• 제38권8호
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• pp.570-575
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• 1994

$\alpha$-Methylpyridine유도체1(a∼f)는 n-BuLi과의 반응에서 $\alpha$-methylenylpyridinium 염 3(a∼f)을 형성한다. 3(a∼f)와 $Me_3SiCl$ 및 $Me_2SiClCH(SiMe_3)CH_2tBu$반응에서 생성물 4(a∼f) 와 5(a∼f)을 형성한다. 화합물 4(a∼f)에 있는 규소원자와 결합된 methylene기의 수소원자는 화합물 4(a∼f)의 $CH_3$기 보다 n-BuLi과의 반응성이 큰 것으로 확인되었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권1호
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• pp.24-34
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• 2019

Soil moisture regulates the fate of methane ($CH_4$) in forest soil via biological and chemical processes. The instant effect of variable precipitation on $CH_4$ uptake is, however, unclear in the forest ecosystems. Here, we measured $CH_4$ flux in a temperate forest soil immediately after variable volume of water applications equivalent to 10, 20 40, and $80mm\;m^{-2}day^{-1}$ precipitation. $CH_4$ uptake was significantly higher when the water was not applied. The $CH_4$ uptake decreased significantly with increasing water application. $CH_4$ uptake was linked with air filled porosity and water filled porosity. $CH_4$ uptake response to actual precipitation intensity was in agreement with $CH_4$ uptake results in this study. $CH_4$ uptake decreased 55% at highest precipitation intensity. Since annual $CH_4$ flux is calculated with interpolation of weekly or biweekly field observations, instant effect of precipitation can mislead the interpolated annual results.

• Animal Bioscience
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• 제34권4호
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• pp.751-758
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• 2021

Objective: The objectives of this study were to investigate the relationship between the mRNA expression of adipocyte type fatty acid binding protein (A-FABP) and heart type FABP (H-FABP) in Thai native chicken crossbreeds and evaluate the level of exotic inclusion in native chicken that will improve growth while maintaining its relatively low carcass fat. Methods: The fat deposition traits and mRNA expression of A-FABP and H-FABP were evaluated at 6, 8, 10, and 12 weeks of age in 4 chicken breeds (n = 8/breed/wk) (100% Chee breed [CH] [100% Thai native chicken background], CH male and broiler female [Kaimook e-san1; KM1] [50% CH background], broiler male and KM1 female [Kaimook e-san2; KM2] [25% CH background], and broiler [BR]) using abdominal fat (ABF) and muscular tissues. Results: The BR breed was only evaluated at 6 weeks of age. At week 6, the CH breed had a significantly lower A-FABP expression in ABF and intramuscular fat (IF) compared with the other breeds. At 8 to 12 weeks, the KM2 groups showed significant upregulation (p<0.05) of A-FABP in both ABF and IF compared to the CH and KM1 groups. The expression of H-FABP did not follow any consistent pattern in both ABF and IF across the different ages. Conclusion: Some level of crossbreeding CH chickens can be done to improve growth rate while maintaining their low ABF and IF. The expression level of A-FABP correlate with most fat traits. There was no consistency of H-FABP expression across breed. A-FABPs is involved in fat deposition, genetic markers in these genes could be used in marker assisted studies to select against excessive fat accumulation.

• 한국세라믹학회지
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• 제36권9호
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• pp.893-900
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• 1999

Silica films were prepared on Si single crystal substrates by sol-gel process using TEOS as starting materials. Films were fabricated by a spin coating technique. Sol solutions were prepared by varying the compositions of CH3OH, H2O and DMF with fixed molar ratio of TEOS=1, HCl=0.05(mol). Wetting behavior viscosity of solutions gelation time thickness of films and cracking behavior were investigated with the various solution compositions. Wetting behaviors of solutions depended on the solution compositions mixing method and mixing rate. The optimum composition of sol was TEOS : DMF ; CH3OH: H2O :HCl=1:2:4:4:0.05(mol) and the mixing rate of solution was optimized at 1 ml/min. Viscosity of solutions were controlled by choosing a reaction time(elapsed time after mixing) at a room temperature so that we could get up to 800nm thick film The surface roughness was getting poor when thickness of films was thicker than 500nm. Thickness of coated films were increased with decreasing amount of CH3OH. The best surface roughness was obtained at the content of CH3OH 4 mol. The shortest gelation time was obtained with the content of CH3OH 8 mol. Crack-free filkms were fabricated when sintered at 500$^{\circ}C$ for 1 hr with heating rate of 0.6$^{\circ}C$/min.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.122-132
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• 2011

Mercury accumulates in biota mainly as methylmercury. In nature, methylmercury shows high affinity to organic matter and $CH_3Hg^+$-organic matter complexation affects the mobility and bioavailabiity of methylmercury. In this study, we examined the methylmercury binding sites in an aquatic humic acid as affected by the pH condition using Hg $L_{III}$-edge extended X-ray absorption fine structure (EXAFS). We evaluated methylmercury binding humic ligands using methylmercury-thiol, methylmerury-carboxyl, and methylmercury-amine complexation models. When $CH_3Hg^+$-to-humic reduced sulfur ratio is 0.3, we found that most of $CH_3Hg^+$ binds to thiol ligands at pH 5 and 7. At pH 7, however, some carboxyl or amine ligand contribution is observed, unlike at pH 5 where $CH_3Hg^+$ almost exclusively binds to thiol ligands. The carboxyl or amine ligand contribution may indicate that some types of thiol ligands in the natural organic matter have relatively low complexation constants or acid dissociation constants compared to those of some carboxyl or amine ligands. Analysis results indicate that ~0.2 fraction of methylmercury binds to amine or carboxyl ligands and ~0.8 to thiol ligands at pH 7.

• Animal cells and systems
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• 제1권3호
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• pp.483-489
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• 1997

This study was performed to investigate the differentiation and distribution of choline acetyltransferase (ChAT}-immunoreactive cells in the magnacellular preoptic nucleus (MCPO) of the postnatal and adult rat forebrains, utilizing techniques of immunocytochemistry. According to the cell shape and the ratio of long axis versus short axis of cell soma, the ChATimmunoreactive nerve cells in the MCPO were classified into six types: 1) round, 2) oval, 3) elongated, 4) fusiform, 5) triangular, and 6) polygonal types. Frequency distributions of the oval and round nerve cells on the postnatal day (PND) 0 were observed to be high. But in the adult, frequency distributions of the same cells were shown to decrease. Compared to those of the postnatal rats, frequency distributions of elongated, fusiform, triangular, and polygonal nerve cells in the adult were increased. The total mean volumes of ChAT-immunoreactive cell somata in the MCPO of PND 0 rat were the lowest, while those in the PND 17 rat were shown to be the highest and decreased in the adult. The soma volumes of the immunoreactive cells at the PND 17 were evenly distributed, but those in the other developmental stages (e.g. PND 7 and adult) appeared to exhibit unimodal distributions. On the electron micrography, the free ribosomes, polysomes, and rough endoplasmic reticula (RER) of the nerve cells in the MCPO of PND 21 rat forebrains were immunoreactive to ChAT in the tissues untreated with triton X-100. According to the observations in the present study, it is considered that the ChAT-immunoreactive nerve cells in the MCPO of the rat forebrains are differentiated throughout the following processes during the postnatal development: 1) increase in cell soma volumes, 2) development of neurites, 3) increase in the frequency of differentiated cell types, and 4) decrease in cell soma volumes. The ribosomes, polysomes, and RER are considered to be closely related to the intracellular localization and biosynthesis of the ChAT but not Golgi complex.

• Journal of Nutrition and Health
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• 제56권2호
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• pp.123-139
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• 2023

구기엽 추출물 (LLE)과 클로로필을 제거한 구기엽 추출물 (LLE(Ch^-))이 MCD diet로 비알코올성 지방간을 유도한 C57BL/6 mouse와 팔미트산으로 지방 축적을 유도한 HepG2 세포에서 지방축적의 억제에 미치는 영향을 검토하였다. 대조군 대비 LLE(Ch^-)는 혈장 TG 농도와 혈장 AST와 ALT의 활성을 유의하게 감소시켰으며 LLE군에서는 혈장 ALT 활성이 유의하게 감소하였다. 두 군 모두 간조직의 TG와 cholesterol 함량을 유의하게 낮추었으며 간조직의 병리학적 변화 결과에서 LLE군에 비해 LLE(Ch^-)군에서 지방축적의 억제효과가 더 크게 나타났다. 팔미트산 0.5 mM을 처리한 HepG2 세포에서 LLE와 LLE(Ch^-)가 1,000 ㎍/mL 농도까지 독성이 없었으며 대조군에 비하여 각각 200 ㎍/mL과 500 ㎍/mL 농도부터 세포 내 지방 축적량을 유의하게 감소시켰고 pAMPK와 pACC 발현이 농도 의존적으로 증가하였으며 FAS발현은 농도 의존적으로 억제되었다. 결과적으로 구기엽 100% 에탄올 추출물들은 간조직의 지방 축적을 억제할 수 있으며 그 효과는 클로로필 제거 구기엽의 활성이 좀 더 큰 것으로 나타났다. 따라서 이 두 소재 모두 항 지방간 효능이 있는 것으로 판단되며 기능성 소재로서의 개발 가능성을 확인하였다.

• 대한화학회지
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• 제24권4호
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• pp.288-294
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• 1980

$CH_3O(CO)Cl,\;CH_3S(CO)Cl\;및\;CH_3S(CS)Cl$/TEX>의 가메탄올 분해반응속도를 메탄올-아세토니트릴 혼합용매하에서 결정하였다. 반응속도는 주로 벌크한 용매성질에 의해서만 아니라 일부 친전자적 특수용매화에 의해서도 영향을 받는다는 것이 실험결과로 알려졌다. 용매의 극성은 반응속도에 영향을 미치는 중요인자는 아니지만, $S_N1$형의 천이상태 안정화에 기여함을 알았다. $CH_3S(CS)Cl$/TEX>의 가메탄올 분해반응은 메탄올에 의한 이탈기의 특수 용매효과 및 큰 유전상수를 가진 용매에 의한 천이상태 안정화가 중요한 $S_N1$형으로 진행됨을 알았다. $CH_3O(CO)Cl$의 가메탄올 분해반응은 위의 경우와는 반대로 $S_N2$형으로 진행됨을 알았다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권4호
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• pp.478-482
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• 2000

Whole cassava (Manihot esculenta, Crantz) crop was harvested about 10-15 cm above ground at 3 months after planting and sun dried for 1-3 days or until the leaves were crispy-dried and the branches and stems were mostly wilted to produce cassava hay. Cassava hay (CH) contained 86.3% DM, 8.9% ash, 23.6% CP, 44.3% NDF, 30.0% ADF, 5.8% ADL, 0.257% condensed tannin and 0.35 mg % HCN, respectively. In addition, CH contained relatively higher amino acid than alfalfa hay especially methionine, isoleucine, leucine and lysine. Ruminal fermentation of CH resulted in high concentrations of $C_2$, $C_3$, and $C_4$ at 72, 17 and 7 mol/100 mole, respectively. A feeding trial was conducted to study on effect of feeding of cassava hay in late lactating dairy cows fed on urea-treated rice straw during the dry season on their intake, ruminal pH, $NH_3$-N, milk yield and compositions. Thirty, Holstein-Friesian crossbred cows in their first lactation were randomly assigned in a randomized complete block design to receive five different dietary treatments: T1=supplementation of concentrate to milk yield at 1:2, T2=supplementation of concentrate to milk yield at 1:2+0.56 kg DM, T3=supplementation of concentrate to milk yield at 1:3+1.3 kg DM CH, T4=supplementation of concentrate to milk yield at 1:4+1.70 kg DM CH, T5=CH fed on ad libitum+small concentrate supplement. All cows received urea-treated rice straw as a roughage source throughout a 80 d feeding trial. The experiment revealed that cassava hay contained high level of protein and minimal level of tannin at 3 months of harvest. Tannin intake ranged from 1.44 to 13.36 g/hd/d and did not affect on urea-treated rice straw intake. Milk yield across treatments were similar (5.4-6.3 kg/hd/d) (p>0.05) but 3.5% FCM was highest in cows received CH at 1.70 kg/hd/d. Feeding of cassava hay resulted in increasing milk fat (4.0 to 4.6%) (p<0.05) and milk protein (3.8 to 5.3%) (p<0.05). Moreover, the use of CH could reduce concentrate supplementation to milk yield from 1:2 to 1:4, respectively, thus resulted in more milk income return.