• Reproductive and Developmental Biology
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• 제34권1호
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• pp.47-53
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• 2010

Glycoprotein hormones have a common $\alpha$-subunit that is involved in the signaling pathway together with G protein, adenylcyclase and cAMP induction; however, it is an unclear how this common structure is related to hormonal action. To determine the biological functions of the COOH-terminal amino acids in the $\alpha$-subunit of these glycoprotein hormones, a tethered-molecule was constructed by fusing the $NH_2$-terminus of the $\alpha$-subunit to the COOH-terminus of the $\beta$-subunit of equine chorionic gonadotropin (eCG). The following deletion mutants were created by PCR; Ile was inserted at position 96 to form ${\Delta}96$, Lys was substituted at position 95 to form ${\Delta}95$, His was inserted at position 93 to form ${\Delta}93$ and Tyr was substituted at position 87 to form ${\Delta}87$. Each mutant was transfected into CHO-K1 cells. Tethered-wt eCG, and ${\Delta}96$, ${\Delta}95$, and ${\Delta}93$ mutants were efficiently secreted into the medium but the ${\Delta}87$ mutant was not secreted. Interestingly, the RT-PCR, real-time PCR, and northern blot analyses confirmed that the RNA was transcribed in the ${\Delta}87$ mutant. However, the ${\Delta}87$ mutant protein was not detected in the medium or the intracellular fraction of the cell lysates. The LH- and FSH-like activities of the recombinant proteins were assayed in terms of cAMP production using rat LH/CG and rat FSH receptors. The metabolic clearance rate (MCR) was determined by injecting rec-eCG (2 IU) into the tail vein. The ${\Delta}95$ and ${\Delta}93$ mutants were completely inactive in both the LH- and FSH-like activity assays. The ${\Delta}96$ mutant showed slight activity in the LH-like activity assay. In comparison to the wild type, the activity of the ${\Delta}96$ mutant in the FSH-like activity assay was the highest among all the mutants. The MCR assay in which rec-eCG was injected showed a peak at 10 min in all the treatment groups, which disappeared 4 h after injection. These results imply a direct interaction between the receptor and the COOH-terminal region of the a-subunit. The data also reveal a significant difference in the mechanism by which the eCG hormone interacts with the rLH and rFSH receptors. The COOH-terminal region of the $\alpha$-subunit is very important for the secretion and functioning of this hormone.

• Geomechanics and Engineering
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• 제13권2호
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• pp.333-352
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• 2017

A comparison study is made between the dynamic properties of an argillaceous siltstone and its grouting-reinforced body. The purpose is to investigate how grout injection can help repair broken soft rocks. A slightly weathered argillaceous siltstone is selected, and part of the siltstone is mechanically crushed and cemented with Portland cement to simulate the grouting-reinforced body. Core specimens with the size of $50mm{\times}38mm$ are prepared from the original rock and the grouting-reinforced body. Impact tests on these samples are then carried out using a Split Hopkinson Pressure Bar (SHPB) apparatus. Failure patterns are analyzed and geotechnical parameters of the specimens are estimated. Based on the experimental results, for the grouting-reinforced body, its shock resistance is poorer than that of the original rock, and most cracks happen in the cementation boundaries between the cement mortar and the original rock particles. It was observed that the grouting-reinforced body ends up with more fragmented residues, most of them have larger fractal dimensions, and its dynamic strength is generally lower. The mass ratio of broken rocks to cement has a significant effect on its dynamic properties and there is an optimal ratio that the maximum dynamic peak strength can be achieved. The dynamic strain-softening behavior of the grouting-reinforced body is more significant compared with that of the original rock. Both the time dependent damage model and the modified overstress damage model are equally applicable to the original rock, but the former performs much better compared with the latter for the grouting-reinforced body. In addition, it was also shown that water content and impact velocity both have significant effect on dynamic properties of the original rock and its grouting-reinforced body. Higher water content leads to more small broken rock pieces, larger fractal dimensions, lower dynamic peak strength and smaller elastic modulus. However, the water content plays a minor role in fractal dimensions when the impact velocity is beyond a certain value. Higher impact loading rate leads to higher degree of fragmentation and larger fractal dimensions both in argillaceous siltstone and its grouting-reinforced body. These results provide a sound basis for the quantitative evaluation on how cement grouting can contribute to the repair of broken soft rocks.

• Journal of Yeungnam Medical Science
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• 제3권1호
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• pp.229-235
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• 1986

rat에 주사된 lithium 이온의 배설에 미치는 수종의 corticosteroid의 영향을 검색한 결과 다음과 같은 결론을 얻었다. 1. fludrocortisone을 10mg/kg 투여하여 혈청내 lithium 농도를 줄일 수 있었고, lithium의 뇨중 배설량도 증가시켰다. 2. dexamethasone을 0.1mg/kg 투여하여 혈청내 lithium 농도를 줄일 수 있었고, 1mg/kg을 투여하여 lithium의 뇨중 배설량도 증가시켰다. 3. dexamethasone에 의하여서는 혈중 $Na^+$의 $K^+$에 대한 농도비가 감소하였고, 반대로 뇨중 $Na^+$의 $K^+$에 대한 농도비가 감소하였다. 이상의 실험 결과를 미루어 corticosteroid는 lithium의 뇨중 배설량을 증가시키고 그 혈중 농도를 감소시킬 수 있으나, 이러한 작용은 신장을 통한 $Na^+$ 이나 $K^+$의 이동과는 전혀 상관이 없다고 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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• pp.335-356
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• 1997

Injection of bovine growth hormone (bGH) to lactating dairy cows increases milk yield and yields of milk components including fat. It is generally believed that most of the anabolic effects derived from bGH in animal tissues are primarily mediated by IGF-1. IGF-1 is a strong anabolic peptide in the plasma of animals and exerts mitogenic and metabolic effects on target cells. Contrary to most protein hormones, the majority of IGF-1 in circulation is bound to the binding proteins (IGFBPs) which are known to be responsible for modifying the biological actions of IGF-1, thus making determinations of IGF-1 actions more difficult. On the other hand, fat is a major milk component and the greatest energy source in milk. Currently, the fat content of milk is one of the major criteria used in determining milk prices. It has been known that flavor and texture of dairy products are mainly affected by milk fat and its composition. Acetyl-CoA carboxylase (ACC) is the rate limiting enzyme which catalyzes the conversion of acetyl-CoA to malonyl-CoA for fatty acid synthesis in 1ipogenic tissues of animals including bovine lactating mammary glands. In addition to the short-tenn hormonal regulation of ACC by changes in the catalytic efficiency per enzyme molecule brought about by phosphorylation and dephosphorylation of the enzyme, the long-term hormonal regulation of ACC by changes in the number of enzyme molecules plays an essential role in control of ACC and lipogenesis. Insulin, at supraphysiological concentrations, binds to IGF-1 receptors, thereby mimicking the biological effects of IGF-1. The receptors for insulin and IGF-1 share structural and functional homology. Furthermore, epidermal growth factor increased ACC activity in rat hepatocytes and adipocytes. Therefore, it can be assumed that IGF-1 mediating bGH action may increase milk fat production by stimulation ACC with phosphorylation (short term) and/or increasing amounts of the enzyme proteins (long term). Consequently, the main purpose of this paper is to give the readers not only the galactopoietic effects of bGH, but also the insight of bGH action with regard to stimulating milk fat synthesis from the whole body to the molecular levels.

• Journal of Nutrition and Health
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• 제23권2호
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• pp.135-147
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• 1990

본 연구는 유기용매로 추출한 마늘의 항암성 성분을 in vitro에서 흰생쥐의 백혈병성 임퐈모 세포인 L$_{1210}$과 P${388} 및 인체 직장암 세포인 HRT-18과 인체 결장암 세포인 HCT-48과 HT-29 또한 invivo에서 흰쥐 복수 육종암세포인 sarcoma-180세포를 대상으로 선별 시험한 것이다. S-180을 제외한 각 암세포는 in vitro에서 마늘추출물을 농도별로 첨가한 배양액에서 배양시험하였다. 암세포의 증식억제효과는 마늘의 석유에텔추출물이 알코올추출물보다 높았다. 마늘의 지용성 성분은 in vitro에서 흰생쥐의 백혈병성 임퐈모 세포, 인체 직장암 및 결장암 세포에 대해 항암효과물을 나타내었다. 각 암세포의 증식률은 첨가한 마늘추출물의 농도가 증가할수록 감소한 영향을 보였다. Petroleum ether/ethyl ether/acetic acid(90:10:1, v/v/v)의 전개용매로 사용한 TCL에서 분리한 유효한 활성성분의 Rf치는 0.18이었고, 정제하지 않은 마늘추출물보다 L$_{1210}$세포에 대해 2.3배 높은 활성을 나타냈다. S-180 암세포로 유발한 흰생쥐에 마늘 추출물을 투여한 군이 투여하지 않은 군보다 생존 기간이 1.5내지 2배 가량 연장효과를 보였다. S-180 암세포를 함유하고 있는 흰 생쥐에 마늘추출물(3ug/head)을 복강내 주사하고 3시간 후에 관찰한 결과 S-180 암세포의 뚜렷한 형태변화를 관찰하였다.

• 대한환경공학회지
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• 제27권10호
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• pp.1081-1089
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• 2005

본 연구에서는 기존에 중유를 사용하는 상용보일러에서 오리멀젼 연료의 활용 가능성을 평가하기 위하여 소형 보일러에서 오리멀젼 연료의 기본적인 연소특성을 실험과 더불어 수치해석하였다. 오리멀젼의 주요 연소특성은 최고 화염온도가 버너로부터 $20{\sim}30\;cm 뒤쪽에 나타나는 화염지연현상과 비교적 넓게 분포하는 화염의 형태로 이는 오리멀젼 제조과정에서 포함된 높은 수분함량과 미세한 수부액적으로 이한 미소폭발 현상에 기인한다. 오리멀젼 연료의 연소특성에 미치는 영향을 평가하기 위하여 연료공급량, 무화유체의 종류, 그리고 계산에 사용된 현상학적인 복사모델과 같은 중요한 설계 및 운전인자에 대한 일련의 변수연구를 수행하였다. 연소특성인 최고 화염온도 지연현상은 연료공급 속도를 조절함으로써 어느 정도 저감시킬 수 있었으며 연소생성물로 CO와 $SO_2$ 그리고 NO가스의 연소로 내 발생특성을 평가하였다. 또한 무화용 유체로 증기를 사용하였을 경우 로내 연소상태는 무화용 공기에 비해 안정화 되고 고온영역이 감소되는 결과를 보였다. 일반적으로 본 연구에서 수행한 실험조건에 대한 수치해석 결과는 물리적으로 일관성 있는 결과를 제시하였으나 오염물질 생성농도에 대한 보다 정확한 예측을 위해서는 추후 현상학적인 모델개선을 필요로 한다. 결국 본 연구로부터 개발된 컴퓨터 프로그램은 기존의 상용화 중유 보일러에서 오리멀젼 연료로 대체 사용시 개선사항 및 유용한 운전 자료를 제공할 것으로 판단된다.

• 한국산학기술학회논문지
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• 제17권12호
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• pp.482-487
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• 2016

파장 400 nm 이하의 자외선은 눈 건강에 매우 해롭다. 특히 UVA (315 nm ~ 400 nm)는 백내장, 설안염, 초자체경화 등을 유발할 수 있고, UVB (280 nm ~ 315 nm)는 결막염, 각막염 및 설안염 등을 일으킬 수 있다. 따라서 폴리머 안경렌즈를 사용함에 있어서 자외선의 차단 기능과 가시광선 영역에서 투과되는 빛을 증가시키고, 안경렌즈 표면에서 형성되는 허상을 방지하는 반사방지 기능은 매우 중요하다. 본 연구에서는 m-자일릴렌 디이소시아네이트 모노머와 2,3-Bis-1-propanethiol 모노머 및 벤조트리아졸 UV 흡수제 (SEESORB 709), 안료 혼합물, 이염화 이부틸 주석 촉매제, 알킬인산 에스터 이형제 등의 혼합물을 인젝션 몰드 방법으로 열중합 공정을 적용하여, 굴절률 1.67의 고굴절률 폴리머 안경렌즈를 제조하였다. 폴리머 안경렌즈 표면에서의 반사를 줄이기 위하여 렌즈 양면에 다층박막 반사방지 코팅을 E-beam 증착 시스템으로 코팅하였다. 자외선 차단 폴리머 안경렌즈의 광학적 특성을 UV-visible spectrometer로 분석하였고, 반사방지층을 구성하는 박막의 굴절률, 표면거칠기 등과 같은 박막소재 특성을 각각 Ellipsometry 및 원자힘 현미경으로 분석하였다. 분석 결과 제조된 안경렌즈는 395 nm 파장 이하의 자외선을 99% 이상 완벽하게 차단하였다.

• 한국임상수의학회지
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• 제23권4권
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• pp.388-392
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• 2006

80두의 가토 간에 $1{\sim}2mm^3$ 크기의 VX2 종양세포를 직접 주입하여 단일간암모델을 만들고, 종양이식 후1주, 2주, 3주째에 CT촬영을 실시하여 생성된 종양의 크기와 조영 양상을 관찰하고 조직병리학적검사로 종양의 진위 여부를 확인하였다. 80두 중 66두(82.5%)에서 단일 종양이 만들어졌다. 나머지 12두 중 1두에서 간외종앙의 생성, 그리고 다른 1두에서 육아종성 종괴가 관찰되었으며, 4두는 폐사하였다. 나머지 8두에서는 종양이 생성되지 않았다. 조영 CT에서 관찰된 종양의 크기는 1주, 2주 그리고 3주째에 각각 $7.4{\times}6.3,\;14.2{\times}10.8,\;16.2{\times}12.6cm$로 측정되었다. 모양은 둥글거나 타원형이었으며, 동맥기에서 중앙에 저감쇠와 변연에 조영증강을 보였으며, 문맥기에는 저감쇠를 나타내었다. 종양조직의 이식은 균질한 단일종양모델을 만드는데 매우 유용하고 적합한 방법이며, 조영 CT 촬영술은 간종양 진단 및 다양한 치료방법 적용 후 추적검사에 매우 유용하게 활용될 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2449-2453
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• 2007

L-[18F]FMAU ([18F]1b) was prepared from the precursor 2-O-[(trifluoromethyl)-sulfonyl]-1,3,5-tri-Obenzoyl- α-L-ribofuranose, by coupling the radioactive fluoro-sugar with the corresponding silylated thymine in 4 steps. The final products, including the α and β anomers, were purified using reverse phase HPLC with an appropriate solvent (5% CH3CN/H2O) at a flow rate of 3.0 mL/min. The total elapsed time of synthesis was about 180-200 min from EOB. The α/β anomeric ratio of the compounds was about 1:9, and the radiochemical purity of the product (β-form) was >98% with decay-corrected yields of 25-35%. All radioactive samples were confirmed using co-injection with pure non-radioactive analogues in every step. In the cellular uptake in vitro test of herpes simplex virus-thymidine kinase (HSV1-TK) gene expressed cells, the percent uptake of injected dose (%ID) of L- and D-FMAU was 37.28 and 65.86, respectively after 240 min incubation. However, the relative uptake (MCA-TK/MCA cellular uptake ratio) of L-FMAU was higher than that of D-FMAU (%ID of L-FMAU, 0.36 and D-FMAU, 0.93 after 240 min incubation in MCA cells). This means that L-FMAU will show better specific HSV1-TK gene expressed cell uptake for selective HSV1-TK gene imaging.

• 약학회지
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• 제34권6호
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• pp.375-383
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• 1990

The pharmacokinetics of haloperidol were determined after single oral and intravenous doses in 13 male schizophrenic patients. Plasma concentrations of haloperidol(HP) and reduced haloperidol(RH) were measured by high performance liquid chromatography. Plasma concentration data obtained were analyzed by obth model dependent (one-or two exponential decay models using nonlinear regression) and model independent (AUC and first moment curve) approaches. The two methods were found to be in close results. After intravenous injections of HP in 8 patients (10 mg/man), the mean central and peripheral volume of distributions were $2.85\;{\pm}\;1.70$ and $8.09\;{\pm}\;2.10\;l/kg$, respectively, and mean steady state volume of distribution was $11.87\;{\pm}\;3.21\;l/kg$. Mean clearance, MRT and elimination half life were $12.39\;{\pm}\;3.25\;ml/min/kg$, $925.10\;{\pm}\;166.79\;min$ and $676.35\;{\pm}\;126.45\;min$, respectively. After oral administrations of HP in 5 patients, mean peak time and peak concentration were $217.63\;{\pm}\;61.60\;min$ and $9.77\;{\pm}\;2.92\;ng/ml$, respectively. Mean MRT and elimination half life were $1112.23\;{\pm}\;131.73\;min$ and $724.02\;{\pm}\;120.03\;min$, respectively, and these parameters were not significantly different from those of intravenous injection of HP. Absolute bioavailability of HP oral product was found to be about 44%. The profiles of plasma RH concentration-time curves after oral or intravenous doses of HP were similar. Also it was found that the elimination rate of RH was solwer than that of HP by comparing the slopes of plasma concentration-time curves of HP and RH.