• Title/Summary/Keyword: Half Life

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Characteristics Related to Domestic Accidents of the Elderly (노인의 주택내 사고발생에 영향을 미치는 요인에 관한 연구)

  • Kwak, In-Suk
    • Journal of Families and Better Life
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    • v.27 no.4
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    • pp.55-66
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    • 2009
  • Nearly a half of the accidents the old people had take place in home. Home safety will be more important than ever in rapidly increasing old aged in Korea. The purpose of this paper is to search the general characteristics of domestic accidents related to living environment of the old people experienced. The number of 248 respondents who had experienced of housing related accidents since recent 10 years were selected from 500 interviews with 65 years old and over during April 4th-26th, 2008. About a half of respondents had experienced home accidents. The entrance is the most common places the home accidents occurred, followed by bathrooms and stairs. flooring materials and raised floors are the most dangerous spots. Both places and dangerous objects are related each other. The place is also related to the type of dwelling. Slipping and tripping over most frequently happen in home accidents. It is related to the place like slipping in a bathroom or stairs, and tripping over in entrances. Mostly, legs and arms are injured by the home accidents. A safe home facilitates the old to live healthy and independent in their own places. A safe home for the old is a kind of new issues in Korea. Related policies and researches are about to sprout.

Design of Electronic Ballast Reducing Acoustic Resonances Phenomina in Metal Halide Discharge Tube (메탈 할라이드 방전관 내의 음향 공명을 감소시킨 전자식 안정기 설계)

  • 김기정;박종연
    • The Transactions of the Korean Institute of Power Electronics
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    • v.4 no.5
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    • pp.405-412
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    • 1999
  • Meta! Halide Discharge(]\1HD) Iamps have good color rendition, long life and good focusing capability but h have flickers bv acoustic resonances. We have designed the electronic ballast for reducing acoustic resonances in high pressure discharge tube. The ballast consists of main two parts, the first part is a half-bridge inverter to make a square wave form a and the st'Cond part is a flyback converter to combine the low frequency and high frequency component. As a r result of this study, we conclude that MHD lamps of 70 watt 따c very well light(D without acoustic resonance p phenomena by the elestronic ballast.

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The Analysis of Flow Circulation System for HANARO Flow Simulated Test Facility (하나로 유동모의 설비의 유체순환계통 해석)

  • Park, Yong-Chul
    • 유체기계공업학회:학술대회논문집
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    • 2002.12a
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    • pp.419-424
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    • 2002
  • The HANARO, a multi-purpose research reactor of 30 MWth open-tank-in-pool type, has been under normal operation since its initial criticality In February, 1995. Many experiments should be safely performed to activate the utilization of the HANARO. A flow simulation facility is being developed for the endurance test of reactivity control units for extended life times and the verification of structural integrity of those experimental facilities prior to loading in the HANARO. This test facility is composed of three major parts; a half-core structure assembly, flow circulation system and support system. The flow circulation system is composed of a circulation pump, a core flow pipe, a core bypass flow pipe and instruments. The system is to be filled with de-mineralized water and the flow should be met the design flow to simulate similar flow characteristics in the core channel of the half-core test facility to the HANARO. This paper, therefore, describes an analytical analysis to study the flow behavior of the system. The computational flow analysis has been performed for the verification of system pressure variation through the three-dimensional analysis program with standard k-$\epsilon$ turbulence model and for the verification of the structural piping integrity through the finite element method. The results of the analysis are satisfied the design requirements and structural piping integrity of flow circulation system.

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Inter-Domain Signal Transmission within the Phytochromes

  • Song, Pill-Soon
    • BMB Reports
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    • v.32 no.3
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    • pp.215-225
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    • 1999
  • Phytochromes (with gene family members phyA, B, C, D, and E) are a wavelength-dependent light sensor or switch for gene regulation that underscore a number of photo responsive developmental and morphogenic processes in plants. Recently, phytochrome-like pigment proteins have also been discovered in prokaryotes, possibly functioning as an auto-phosphorylating/phosphate-relaying two-component signaling system (Yeh et al., 1997). Phytochromes are photochromically convertible between the light sensing Pr and regulatory active Pfr forms. Red light converts Pr to Pfr, the latter having a "switch-on" conformation. The Pfr form triggers signal transduction pathways to the downstream responses including the expression of photosynthetic and other growth-regulating genes. The components involved in and the molecular mechanisms of the light signal transduction pathways are largely unknown, although G-proteins, protein kinases, and secondary messengers such as $Ca^{2+}$ ions and cGMP are implicated. The 124-127 kDa phytochromes form homodimeric structures. The N-terminal half contains the tetrapyrrolic phytochromobilin for red/far-red light absorption. The C-terminal half includes both a dimerization motif and regulatory box where the red light signal perceived by the chromophore-domain is recognized and transduced to initiate the signal transduction cascade. A working model for the inter-domain signal communication within the phytochrome molecule is proposed in this Review.

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Stability and Dissolution Enhancement of Omeprazole by Pharmacentical Formulation (오메프라졸의 제제화 및 평가)

  • Jee, Ung-Kil;Lee, Gye-Won;Jeon, Un-Jong
    • Journal of Pharmaceutical Investigation
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    • v.22 no.4
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    • pp.281-287
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    • 1992
  • Omeprazole (OMZ) is very unstable in acidic solution, which selectively inhibit the release of the gastric juice in the gastric mucosa, In order to stabilize (OMZ) in oral solid dosage form, the enteric-coated microcapsules and compression-coated OMZ tablets containing lysine or arginine as stabilizer were prepared and their dissolution and stability test were performed. The haif life of OMZ microcapsules containing arginine was 194 days at $30^{\circ}C$ and OMZ was completely released in 60 min. The half-lives of enteric coated and non-coated compression-coated OMZ tablets with lysine were 292 and 95 days at $30^{\circ}C$, respectively. The half-lives of enteric coated and non-coated compression-coated tablets with arginine were 1752 and 293 days at $30^{\circ}C$, respectively, and OMZ were released completely in 20 min in the 2nd fluid of K.P.VI. Consequently, the enteric-coated compression-coated OMZ tablets with arginine as stabilizer provided a good formulation for oral solid dosage form.

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Nitrate Uptakes by Microorganisms Isolated from the Soils of Greenhouse

  • Cho, Kwang-Hyun;Lee, Gyeong-Ja;Ahn, Hae-Jin;Kim, Young-Kee
    • Journal of Applied Biological Chemistry
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    • v.48 no.1
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    • pp.11-15
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    • 2005
  • Salinity of soils in greenhouse has been increased by massive application of fertilizers. Nitrogen fertilizer was most popular, and thus nitrate became the majority of soil salinity. Accumulation of nitrate led to deleterious effects on the growth and development of crops and vegetables. Microbial strains able to utilize nitrate and thus remove excess nitrate from farm land soils were isolated from 15 different soils of greenhouses and plastic film houses. Four strains able to grow in medium containing 50 mM $KNO_3$ were isolated, among which only E0461 showed high capacity of nitrate uptake. Nitrate uptake by E0461 was dependent on culture medium and was increased by addition of tryptone and peptone. Although E0461 was able to grow without tryptone and peptone, growth was slow, and no nitrate uptake was observed. Nitrate appeared to facilitate E0461 growth in the presence of tryptone and peptone. Through kinetic analysis, nitrate uptake was measured at various concentrations of nitrate, and half-life was calculated. Nitrate concentration decreased with increasing incubation period, and plot between half-lives and initial concentrations of nitrate fitted to single exponential function. These results suggest one major factor plays an important role in microbial nitrate uptake.

CAN WE MEASURE A REMOTE SENSING SCIENCE? BIBLIOMETRIC ANALYSIS OF THE LITERATURE, 1975-2005

  • Nabiullin, Ahat A.;Shoom, Mariya Yu.
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.340-343
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    • 2006
  • Remote sensing science is a rapidly growing field of Earth sciences. Since emergence and to present day, an extensive literature has evolved which traces the wide application of remote sensing in human activities. According to the ISI Web of Science in the 1975-2005 time span more then 20,000 papers were published on remote sensing. The number of papers grew exponentially with doubling period of about 6 years. Notwithstanding all specialized proceedings, there is a lot more remote sensing papers published in a vast list of source titles (up to 350 proceedings). Only 25% of retrieved papers are published in 10 proceedings which ISI assigns to subject category of remote sensing. In 2005 all these proceedings published 1291 articles and received cca 24,000 citations. Average impact factor of the proceedings is equal to 1.181 and average cited half-life is 7.1. It means that an average paper in remote sensing proceedings is cited more then once per year and half of citations the paper receive within the next 7 years after publication. The time line of remote sensing periodicals issued in 1927-1995 shows an exponential growth with doubling period about 15 years. After 1995 there is a prominent deviation from the exponential curve which shows the demand saturation for specialized proceedings. The features revealed are discussed in terms of dynamics and impact of remote sensing in current Earth sciences development.

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Characterization of the Catalytic Properties of Recombinant Acetohydroxyacid Synthase from Tobacco

  • Kim, Joung-Mok;Choi, Jung-Do;Kim, Bok-Hwan;Yoon, Moon-Young
    • Bulletin of the Korean Chemical Society
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    • v.26 no.2
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    • pp.260-264
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    • 2005
  • The nature of the active site of Tobacco acetohydroxyacid synthase (AHAS) in the substrate- and cofactorbinding was studied by kinetics and fluorescence spectroscopy. The substrate saturation curve does not follow Michaelis-Menten kinetics at different temperatures (7, 21 and 37 ${^{\circ}C}$), pH (6.5, 7.5 and 8.5) and buffers (Tris-HCl and MOPS). The concentration of one half of the maximum velocity ($S_{0.5}$) decreased in the following order: pyruvate $\gt$ ThDP $\approx$$Mg^{+2}$ $\gt$ FAD. However, the catalytic efficiency (K$_{cat}/S_{0.5}$) inversely decreased in the following order; FAD $\gt$ $Mg^{+2}$ $\approx$ThDP $\gt$ pyruvate, indicating that the cofactors by in decreasing order; FAD, $Mg^{+2}$, ThDP, affect the catalysis of AHAS. The dissociation constant ($K_d$) of the intrinsic tryptophan fluorescence decreased with the same tendency of the concentration of one half of the maximum velocity ($S_{0.5}$) decreasing order. This data provides evidence that the substrate and cofactor binding natures of the active site, as well as its activation characteristics, resemble those of other ThDP-dependent enzymes.

Pharmacokinetics and Renal Excretion of Sulfamethoxazole in Sheep

  • Shah, Bukhtiar;Mawaz, M.;Ijaz-Javed;Anwar-ul-Hassan-Gilani
    • Archives of Pharmacal Research
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    • v.12 no.3
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    • pp.154-159
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    • 1989
  • Pharmacokinetics and urinary excretion of sulfamethoxazole were investigated in healthy sheep. From the plasma disappearance curves after intravenous bolus injection (50 mg/kg), the half-life and volume of distribution were found to be 76 $\PM$14 min and 0.41 $\PM$ 0.18 lit/kg respectively. Body clearance was 4.06 $\PM$ 1.03 ml/kg/min. Very low Concentration of ddrug was present in plasma after 3 hours of administration and plasma level at 6 hour was only 4.4 $\PM$ 2.0 $\mu$g/ml. The renal clearance of sulfamethoxazole (22 $\PM$ 2.17 ml/min/10 kg) exeeded the creatinine clearance (9.78 $\PM$ 1, 57 ml/min/ 10 kg) which may be due to involvement of active tubular secretion and pH dependent back diffusion. Half of the dose of sulfamethoxazole was excreted as unchanged free drug while acetylated amine comprised of 20 percent within the first 6 hours of drug administration.

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Protective efficacies of Aronia melanocarpa (Blackberry) on the Allyl Alcohol-damaged Hepatocyte of Mice (쥐의 알코올성 간세포 손상에 대한 Aronia melanocapa(Blackberry)의 보호효과)

  • Han, Sang-Zin
    • Korean Journal of Pharmacognosy
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    • v.44 no.1
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    • pp.91-96
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    • 2013
  • The results of the alcohol decomposition ability of Aronia melanocarpa are as follows. Plasma alcohol concentration of the Aronia group was ca. 48.9% lower than the control group, but half an hour faster in that of Aronia before alcohol group, ca. 54.9% higher and half an hour later than that of the control group. ALDH(acetaldehyde dehydrogenase) of the Aronia group was ca. 243% higher than that of the control group. But maximal ALDH of the group taking Aronia before alcohol administration showed 0.5h faster and ca. 267% higher than that of the control group. This result shows that the activity of ALDH was increased by the Aronia. Aronia group's AST and ALT are increasing with similar patterns and their levels continually under the control's, but ca. 12.6% lower at AST and ca. 19.0% lower at ALT than those of control group. Ca. 21.7% lower at AST and ca. 40.5% lower at ALT in the Aronia group before alcohol administration than those of the control group. This result shows that Aronia has a role of suppressor against the liver damage. Therefore, this study proved lucidly the protective effects of Aronia on the hepatocyte.