• 제목/요약/키워드: half-lives

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Growth Hormone Signaling in the Regulation of Acid Labile Subunit

  • Kim, Jin Wook;Boisclair, Yves R.
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권5호
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    • pp.754-768
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    • 2008
  • The past decades have seen enormous advances in our understanding of how GH acts. GH is a pituitary-derived polypeptide hormone that has diverse physiological effects including the regulation of bone growth, carbohydrate and lipid metabolism. The effects of GH are mediated directly and indirectly through IGF-I. In addition, GH stimulates the hepatic production of ALS. In postnatal life, IGF-I and -II circulate as 150 kDa ternary complexes consisting of one molecule each of IGFBP-3 or IGFBP-5, IGF-I or IGF-II and ALS. It is now known that ALS increases significantly the half-lives of the IGFs, IGFBP-3 and -5, and therefore is responsible for maintaining a circulating reservoir for each of these proteins.

신규 세파로스포린계 항생물질 DWC-751의 흰쥐 및 생쥐 체내동태 (Pharmacokinetic Study on DWC-751, a New Cephalosporin, in Rats and Mice)

  • 심창구;최은진;이성원;박남준;강영숙;유영효
    • Biomolecules & Therapeutics
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    • 제1권2호
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    • pp.204-210
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    • 1993
  • The distribution and excretion of DWC-751, a new cephalosporin, were examined in rats and mice following a single intravenous administration. DWC-751 in plasma and urine was determined by both HPLC and microbiological assay. The plasma concentration of the drug declined biexponentially. The initial and terminal half lives of the drug were 3.0 and 28.3 min, respectively. Binding of the drug to plasma proteins was 42.3%. The distribution volume at steacly-state ($Vd_{ss}$) was only 0.341 ι/kg, which is well correlated with the low n-octanol/water partition coefficient of the drug ($K_{o/w{\cong}0$) Actually, the drug was distributed to liver, kidney and lung with very low organ/plasma concentration ratio. The drug, was excreted mainly via renal excretion, i.e., the total($CL_T$) and apparent renal($CL_{R}$) clearances of the drug were 10.8 and 7.5 ml/min/kg, respectively.

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수용성 담체와의 공침물 형성에 의한 메토클로프라미드의 용출 증가 (Dissolution Enhancement of Metoclopramide by Coprecipitation with Water-Soluble Carriers)

  • 용재익;정차옥
    • Journal of Pharmaceutical Investigation
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    • 제18권2호
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    • pp.43-47
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    • 1988
  • In order to increase the dissolution characteristics of relatively water-insoluble metoclopramide (MCP), coprecipitates of MCP with polyvinylpyrrolidone (PVP), polyethylene glycol (PEG) 1000, 4000 or 6000 were prepared in various drug to polymer ratios. The dissolution rate of MCP-PVP coprecipitate was greater than those of MCP alone, MCP-PVP physical mixture and MCP-PEG coprecipitates. The dissolution rate of MCP-PEG 6000 coprecipitate was greater than those of MCP-PEG 1000 and MCP-PEG 4000 coprecipitates. The dissolution half-lives $(T_{50%})$ for MCP alone and 1:5 (w/w) MCP-PEG 6000 coprecipitate were determined by the log-probit method at $37^{\circ}C$ and found to be 4.17 and 0.98 min, respectively.

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Older Women Breast Cancer Survivors: Decision Making, Sources of Information and Wellness Activities in Malaysia

  • Mohamed, Nor Aini;Muhamad, Mazanah
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권3호
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    • pp.2043-2048
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    • 2013
  • The purpose of this study mas to profile older breast cancer survivors in Malaysia. In a survey study, a custom made questionnaire was administered to 69 breast cancer patients and survivors between 60 and 84 years of age in Peninsular Malaysia. The main ethnic group recorded was Chinese, followed by Malay and Indian. The majority of women were married (87%) and had children (84.1%). Just over half (53.6%) had primary and secondary education, whereas 24.7% had higher education. Fifty five percent of the study participants made their own decision on treatment, 60.8% exercised at least 3 times in a week, and 56.6% sought information from specialists. Our study suggests that older breast cancer survivors are aware of the importance of exercise in their daily lives and make attempts to be cancer free (e.g. doing exercise, recreational activity and have good relationships with friends and family).

A new environmental barrier layer for organic light-emitting displays

  • Wagner, Sigurd;Mandlik, Prashant;Han, Lin;Silvernail, Jeff A.;Ma, Rui-Qing;Hack, Michael;Brown, Julie J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1063-1064
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    • 2008
  • We have discovered a new single-layer environmental barrier for OLEDs. In storage at $65^{\circ}C$ and 85% relative humidity, OLED pixels encapsulated with this barrier have half-lives of approximately one year. We describe the fabrication and properties of the barrier, and results of accelerated storage tests.

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DPPC Liposome에 미치는 고들빼기 추출물의 DSC 연구 (The Effects of Godulbaegi Extracts on the Fluidity of Phospholipid Liposomes by DSC)

  • 배송자;김남홍;노승배;정복미
    • 한국식품영양과학회지
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    • 제27권3호
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    • pp.518-524
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    • 1998
  • Liposomes have been widely employed as biomembrane-mimetic system and drug-delivery system. In these applications, the low stability of liposomes has been the most serious problem. They have relatively short half-lives and easily lysed through interactions with biological components. This study was performed to investigate the effects of godulbaegi extracts on the fludity of phospholipid liposomes. We used dipalmitoyl phosphatidylcholine(DPPC) liposomes which make most stable liposomes among the other phosphatidylcholines. The thermograms of the DPPC liposomal bilayers incorporated with the hexane extract of godulbaegi(Ixeris sonchifolia H.) were obtained, and the enthalpy changes and the sizes of cooperative unit of the transition were calculated. The incorporation of the Ixeris sonchifolia H. into the liposomal bilayers effectively reduced the transition temperature at which the transition from gel state to liquid-crystalline state occurs, broadened the thermogram peaks, and reduced the ratio of van't Hoff to calorimetric enthalpies. These results indicate indicate that the godulbaegi extracts (Ixeris sonchifolia H.) have significant effects on the fluidity of biological membrance.

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새로운 항혈전 약물인 아스팔라톤의 전처방화 연구 (Preformulation Study of Aspalatone, a New Antithrombotic Agent)

  • 곽혜선;전인구
    • Biomolecules & Therapeutics
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    • 제8권4호
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    • pp.332-337
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    • 2000
  • Physicochemical properties of aspalatone (acetylsalicylic acid maltol ester, AM), which has been recently found to have an antithrombotic effect, were studied in terms of solubility, dissolution, partition coefficient (Pc) and stability. The solubility of AM at 37$^{\circ}C$ was about 1.2 mg/ml and the P$_{c}$ value for n-octanol/water and chloroform/water was 11.4 and 382.6, respectively. Dissolution rates of AM at pH 1.2 and 6.8 were more than 80% within 30 min. The degradation of AM followed apparent first-order kinetics, and was dependent on temperature, pH and ionic strength. From the pH-rate profile, the optimal pH was found to be at around 4.0. Half-lives at pH 1.2 and 6.8 were 33.5 and 44.4 hr, respectively. The degradation rate of AM at pH 1.2 was somewhat faster than that of aspirin, but at pH 7.0, the degradation rate of AM was slower than that of aspirin.n.

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동력경운기(動力耕耘機) 주요부품(主要部品)의 수명추정(壽命推定)에 관(關)한 연구(硏究) (A Study on Life Estimation of Some Major Parts of Power Tiller)

  • 이대원;김경욱;금동혁
    • Journal of Biosystems Engineering
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    • 제8권1호
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    • pp.30-37
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    • 1983
  • Frequent breakdowns of power tiller, particularly in the peak labor constraints, have been a cause of decreasing machine productivity and its efficient utilization. To keep power tiller always ready to work, it may be necessary to identify the failure characteristics of some major parts of power tiller, and to have those parts replaced accordingly before they show the symptom of mulfunction. This study was conducted to identify the failure characteristics of some major parts of power tiller and to estimate their lives (MTBF) using a Weibull distribution function. The result showed that about half of breakdowns currently being occurred may be reduced through timely replacement of those part having wearout failure characteristics.

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Unconditional Clearance Levels for Releasing Radioactive Materials Contaminated with Major Radionuclides from Regulatory Control

  • Cheong Jae Hak;Jeong Chan Woo;Park Won Jae
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2005년도 춘계 학술대회
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    • pp.49-55
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    • 2005
  • Unconditional clearance levels were derived for fifteen short-lived radionuclides. Due to the uncertainty of long-term radiological impact analysis, alpha emitting nuclides and nuclides with half-lives longer than 30 years (except for C-14) were excluded from the scope of this study. The candidate waste streams are solid wastes and waste oil generated from nuclear power reactors. The clearance levels were derived by generic assessment for enveloping scenarios, along with specific assessment for each detailed scenario such as landfill, incineration and recycling. The derived values lie in the range from 0.01 to 100 Bq/g.

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Stability of Carthamin from Carthamus tinctorius in Aqueous Solution;pH and temperature effects

  • Kim, Jun-Bum;Paik, Young-Sook
    • Archives of Pharmacal Research
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    • 제20권6호
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    • pp.643-646
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    • 1997
  • Thermal stability of a red pigment, carthamin, frm Carthamus tinctorius was investigated to explore possible applications as natural color additives for foods, cosmetics, and nutraceuticals. Degree of degradation reactions of carthamin at acidic, neutral and alkaline conditions were determined with UV/V is spectral measurements. Decomposition half lives of carthamin at 25.deg. C were 4.0 h, 5.1 h, and 12.5 h at pH 5.0, pH 7.0, and pH 12.0, respectively, indicating that carthamin is much more stable at alkaline pH than acidic or neutral conditions. The activation energies of carthamin at pH 5.0, pH 7.0, and pH 12.0 were 15.6, 15.7 and 16.8 kcal/mol, respectively.

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