• 제목/요약/키워드: gradient absorption

검색결과 82건 처리시간 0.026초

복강내 확산성 물질의 부위별 흡수속도 (Regional Differences of Entry Rate of Freely Diffusible Substances from Peritoneal Cavity)

  • 조병득;신동훈
    • The Korean Journal of Physiology
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    • 제1권2호
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    • pp.157-168
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    • 1967
  • The entry of antipyrine and urea from the peritoneal cavity of rabbit into organ tissue and blood plasma was studied. Two hundred mg of antipyrine plus 300 mg of urea in 10 ml Ringer's solution was injected into the peritoneal cavity of anesthetized rabbit. The injection was made from above of a rabbit kept tying right side down and it enabled part of the abdominal organs (liver, intestine, kidney) was immersed in the injected solution and kept high concentration gradient throughout the experimental period. The remaining part of the organs was revered only by a thin film of the test solution. Subsequently, in this part of the organs the concentration gradient of the diffusible substances during entry was presumed to decrease as time elapsed. Four pieces of the liver tissue were taken namely, the right superficial, right deep, left superficial and left deep portions. Two were taken from the small intestine, one from the portion which was immersed in. the fluid and the other from that above the fluid mass. Both kidneys were separately analyzed. As a remote organ the gastrocnemius muscle was taken from the right leg of the animal. The intervals which were the time periods elapsed after injections were 5,7,10,15 or 30 minutes. At each point 5 animals were sacrificed and the concentrations of the test substances in the tissue water were measured. The results obtained were as follows. 1. In the liver the right portion which was immersed in the fluid showed higher concentration if the test substances than the left portion and the superficial region exceeded the deep region. The concentrations diminished as the time elapsed after infusion, particulary in the case of antipyrine, suggesting circulatory removal of the substances. In urea such decreasing tendency of the concentration was not obvious, and suggested slower removal rate of it as compared with that of antipyrine. 2. In the small intestine there was no regional difference in the concentration of the test substances. Because of the intestinal motility different portions of the intestine were seemed to have bathed in the fluid of the same concentration. In general the concentrations in the intestinal wall exceeded those of the liver, suggesting a slower removal rate than in the latter. 3. In the kidney the accumulation of the endogenous urea was predominant, and the accumulating mechanism in the renal tissue went on during the period of the experiment. Therefore it revealed increasing tendencies as the time elapsed. The penetration of the test substances in this organ from the peritoneal cavity seemed to be slower than in other abdominal organs, namely liver or small intestine. Part of the test substances in the kidney were obviously brought by the blood stream. 4. Rapid exponential decay of the concentration of antipyrine and of the osmolality of the peritoneal fluid was attributed to the extensive removal through the whole dimension of the peritoneal surface, and the remote organ such as the gastrocnemius muscle attained a fairly close value to that of the abdominal organs in less than 30 minutes. The factors which related to the absorption rate were discussed. They were the concentration gradient, permeability and the regional perfusion rate.

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Simultaneous Analysis of Cholesterol Oxidation Products (COPs) in Powdered Milk Using HPLC/UV-Vis

  • Lee, Jin Joo;Myung, Seung-Woon
    • Bulletin of the Korean Chemical Society
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    • 제34권9호
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    • pp.2787-2794
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    • 2013
  • Cholesterol and cholesterol oxidation products (COPs) may accumulate in foods of animal origin during processing or storage. An effective and sensitive analytical method was developed by increasing the UV absorption of compounds through derivatization by attaching a chromophore to the functional groups of cholesterols (cholesterol, 20-hydroxycholesterol, 7-ketocholesterol, cholestane-$3{\beta}$-$5{\alpha}$-$6{\beta}$-triol, 25-hydroxycholesterol, and $5,6{\alpha}$-epoxycholesterol). The influences of the reaction time, volume of reaction solvent, amounts of derivatizing reagent, and extraction solvents were investigated, as they may influence the reaction and extraction yield. The derivatized COPs were analyzed simultaneously on a C18 column (2.1 mm i.d. ${\times}$ 100 mm length, $3.5{\mu}m$ particle size) using a gradient elution with water and acetonitrile. The derivatized COPs showed increased sensitivity and selectivity in HPLC/UV-Vis. The LOD and LOQ were in the concentration ranges of 0.018-0.55 mg/kg and 0.059-1.84 mg/kg from the powdered milk. And the accuracy and precision were 78.1-116.7% and 1.1-9.9%, respectively.

DISTRIBUTION AND KINEMATICS OF FORMALDEHYDE IN DARK CLOUDS IN M17 AND NGC 2024

  • MINN Y. K.;LEE Y. B.
    • 천문학회지
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    • 제27권1호
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    • pp.31-44
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    • 1994
  • The 4.8GHz formaldehyde absorption line in the dark clouds in M17 and NGC 2024 regions has been mapped. In both nebulae, we detected two $H_2CO$ line components. In M17, the 24km $S^{-1}$ cloud is closely associated with the HII region located in front of the radio continuum source, and the 19km $S^{-1}$ cloud is associated with the visual dark clouds with a larger extent which are closer to us. The 19km $S^{-1}$ cloud has a mass motion approaching to the HII region. In both clouds, a velocity gradient from the north-east to the south-west directions is observed. The linewidth has no variation indicating no collapsing motion. In NGC 2024, the 9km $S^{-1}$ feature is extended along the dark bar in front of the bright nebula and a weak second component at 13km $S^{-1}$ is confined to the immediate vicinity of the radio source. Indications are that the 9km $S^{-1}$ cloud is physically associated with the dark bar and the 13km $S^{-1}$ cloud is located behind the radio source. The angular extent, the column density, and the total mass of the clouds are derived. The radial velocities of other molecular lines observed in these clouds are compared.

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Czochralski 방법에 의한 Nd : YAG 단결정의 육성 및 레이저 출력특성 (Growth of Nd:YAG single crystal by czochralski method and characteristics of laser generation)

  • 이상호;김한태;배소익;정수진
    • 한국광학회지
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    • 제9권3호
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    • pp.175-180
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    • 1998
  • 고체 레이저매질로 가장 널리 쓰이는 Nd:YAG 단결정을 Czochralski 방법으로 육성하였다. 자체 제작한 Czochralski 결정 육성로 및 자동 결정 적경제어 장치를 써서 유효 직경 50mm, 길이 100mm의 Nd3+ 이온농도가 0.9at%이고 <111>방향의 단결정을 육성하였다. 단결정 육성시 융액의 수직방향에 대한 온도구배가 중용한 변수인 것이 확인되었으며, 결정 직경은 자동 제어가 가능하도록 컴퓨터 프로그램을 제작하였다. 육성된 단결정을 절단, 가공, 연마, 코팅 과정을 거쳐서 레이저 발진용 Nd:YAG막대를 제작하고 흡수 스펙트럼, 형과 스펙트럼 분석을 통하여 정확한 Nd:YAG의 레이저 발진특성을 확인하였다. 자체 가공된 레이저 막대로부터 발진된 CW 레이저의 최대 출력은 70W이었고, 발진문턱값과 효율은 각각 1.3kW, 1.64%이었다.

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아마리리스에 모자익병을 일으키는 CMV에 관한 연구 (Isolation and Properties of Cucumber Mosaic Virus Inducing Mosaic Symptoms in Hippeastrum hybridum Hort)

  • 김정수;김흥배;이순형
    • 한국응용곤충학회지
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    • 제20권2호
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    • pp.76-82
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    • 1981
  • 아마리리스에 모자익병을 일으키는 병원바이러스의 기주범위, 물리적성질, 혈청반응을 조사하고 바이러스 입자를 전자현미경으로 관찰을 하였다. 바이러스의 지표식물 검정 결과 C. amaranticolor, V. unguiculata, C. sativus G. globosa둥 21종의 CMV감수성식물에 병징이 나타났다. 바이러스의 내열성은 55C(10분간)이며 내희석성은 $10^{-3}$이고 내보존성은 실온에서 2일이었다. 한천내 확산법을 이용한 항혈청반응결과 뚜렷한 반응대가 형성되었으며, 바이러스흡광도는 260nm에서 최고였으며, 245nm에서 최저였다. 전자현미경에 의한 바이러스입자의 검경결과 직경이 90nm내외인 소구형 입자가 관찰되었다. 이상의 결과를 종합하면 아마리리스에 모자익병을 일으키는 것은 CMV에 의한 것으로 보인다.

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Evaluation of In-Vitro Dissolution and In-Vivo Absorption for Two Different Film-Coated Pellets of Clarithromycin

  • Zhang Xiang-rong;Chen Xiao-yan;Hu Lian-Dong;Tang Xing;Li San-Ming;Zhong Da-fang
    • Archives of Pharmacal Research
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    • 제28권8호
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    • pp.977-982
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    • 2005
  • The aim of this study was to compare two formulations of film-coated pellets containing c1arithromycin after single oral dose study in healthy male volunteers. Two formulations with different coating polymers were prepared: formulation-1 (F-1) was prepared by incorporating three kinds of pH-dependent gradient-release coated pellets into capsules and formulation-2 (F-2) was prepared by coated with an insoluble semiosmotic film. Release profiles of filmcoated pellets were evaluated using paddle method under different conditions. Pharmacokinetic profiles of these formulations were obtained in three healthy male volunteers and compared to commercially available immediate release (IR) tablets. The relative bioavailability based on the $AUC_{0-24h}$ was found to be $96.2\%\;and\;58.7\%$ for F-1 and F-2 compared with IR, and the $T_{max}$ was delayed.

축소모델을 이용한 구조체 접지 분석 (The Analysis of Structure Grounding Using Reduced Scale Model)

  • 길형준;김향곤;한운기;이기연;최충석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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    • pp.2046-2048
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    • 2005
  • This paper deals with ground potential rise of structure grounding electrode when a test current flows through grounding electrode. In order to analyze the potential gradient of ground surface on structure grounding electrode, the reduced scale model has been used. The structures were designed through reducing real buildings and fabricated with four types on a scale of one-one hundred sixty. The supporter was made to put up with weight of structure and could move into vertical, horizontal, rotary direction. When a test current flowed through structure grounding electrodes, ground potential rise was the lowest value at electric cage type(type B). According to resistivity and absorption percentage in concrete attached to structure, the potential distribution of ground surface appeared differently.

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Rhodopseudomonas gelatinosa의 chromatophore에서 시토크롬 $bc_1$ 복합체와 시토크롬 c 산화효소의 확인 및 특성연구 (Identification and characterization of cytochrome $bc_1$ complex and cytochrome c oxidase in chromatophore of rhodopseudomonas gelatinosa)

  • 강대길;최명재;최원기
    • 미생물학회지
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    • 제29권4호
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    • pp.243-249
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    • 1991
  • The chromatophore from the chemotrophically grown facultative anaerobic photosynthetic bacterium, Rhodopseudomonas gelatinosa ATCC 17013 was isolated through stepwise sucrose gradient centrifugation. The isolated chromatophore showed high activities of the cytochrome $bc_{1}$ complex and cytochrome c oxidase. The activity of cytochrome $bc_{1}$ complex was completely inhibited by .5$\mu$M antimycin A,10$\mu$M myxothiazol, and that of cytochrome c oxidase was completely inhibited by .$50\mu$M KCM and $100\mu$M $NaN_{3}$but not inhibited by carbon monoxie. The activity of cytochrome c oxidase of th chromatophore was increased by addition of ionophores or protonophores. The reduced-oxidised difference sspectrum of cytochrome $bc_{1}$ complex isolated by affivity chromatography showed the absorption maxima at 553 nm(shoulder at 547 nm), 520 nm, and 418.5 nm, on the other hand, that of cytochrome c oxidase showed .alpha., .betha. and soret peaks at 554 nm, 523 nm, and 421 nm, respectively. The cytochrome c oxidase from chemotrophically grown Rhodopseudomonas gelatinosa seems to be a b-type cytochrome c oxidase.

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산업폐수열원 이용 증기압축식/흡수식 하이브리드 히트펌프 시스템의 시뮬레이션 (Simulation of Compression/Absorption Hybrid Heat Pump System using Industrial Wastewater Heat Source)

  • 백영진;박성룡;장기창;라호상
    • 설비공학논문집
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    • 제16권12호
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    • pp.1117-1125
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    • 2004
  • In this study, in order to utilize the waste heat of industrial wastewater in the range of the relatively low temperature of 40~5$0^{\circ}C$ as a heat source, a hybrid heat pump system was considered by computer simulation method. In the simulation, an absorber, desorber and solution heat exchanger were modelled by UA values while a compressor and pump performance were specified by an isentropic efficiency. Simulation results show that the performance of hybrid heat pump can be up to 80% higher than that of conventional R134a heat pump when it makes a process hot water of 9$0^{\circ}C$ while the wastewater is cooled down to 2$0^{\circ}C$. As the absorber pressure increases, the system performance and deserter pressure increase with a favorable effect of a compressor discharge gas temperature drop.

광기록매체용 Ge-Sb-Te 다층 박막의 광학적 특성 및 열전달 특성 (Optcal and thermal diffusion properties of Ge-Sb-Te multi-layered thin films for optical recording media)

  • 김도형;김상준;김상열;안성혁
    • 한국광학회지
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    • 제12권5호
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    • pp.394-400
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    • 2001
  • 다층 박막에서의 빛의 반사와 흡수 및 열전달 방정식을 수치해석적으로 풀어 광기록매체용 다층 박막의 광학적 특성과 열전달 특성을 알아보고 이 두 특성들을 모두 고려하여 광기록에 적합한 레이저의 출력 및 지속시간, 다층 박막 구조 상수를 제시하였다. 그 결과 레이저는 650 nm 파장을 기준으로 출력 18mW, 지속 시간 60 nm가 적당하였으며 박막 구조 상수는 ZnS-SiO$_2$140nm, Ge-Sb-Te 20 nm, ZnS-SiO$_2$20~30nm, Al-alloy 100~150 nm가 적당하였다.

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