• Title/Summary/Keyword: pHi

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A musculotendon model including muscle fatigue

  • Jong kwang Lim;Nam, Moon-Hyon
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.352-355
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    • 1998
  • A musculotendon model is investigated to show muscle fatigue under the repeated functional electrical stimulation (FES). The normalized Hill-type model can predict the decline in muscle force. It consists of nonlinear activation and contraction dynamics including physiological concepts of muscle fatigue. A muscle fatigue as a function of the intracellular acidification, pHi is inserted into contraction dynamics to estimate the force decline. The computer simulation shows that muscle force declines in stimulation time and the change in the estimate of the optimal fiber length has an effect only on muscle time constant not on the steady-state tetanic force.

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Studies on the riboxomal RNA genes of rhizobium meliloti and bradyrhizobium japonicum (Rhizobium meliloti와 bradyrhizobium japonicum의 ribosomal RNA 유전자에 관한 연구)

  • 강홍규;김달웅;하지홍
    • Korean Journal of Microbiology
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    • v.26 no.4
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    • pp.312-317
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    • 1988
  • The genes for ribosomal RNA in Rhizobium meliloti and Bradyrhizobium japonicum were analyzed by southern hybridization of BamHI, EcoRI, HindIII digested chromosomal DNA with purified 5' $^{32}P$-labeled 16S and 23S rRNA. The big differences in the hybridization pattern of both rhizobia were found. The comparative results were discussed in relation to the copy number and conservativity of restriction sites in the rRNA genes of both rhizobia.

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Comparison and evaluation of volumetric modulated arc therapy and intensity modulated radiation therapy plans for postoperative radiation therapy of prostate cancer patient using a rectal balloon (직장풍선을 삽입한 전립선암 환자의 수술 후 방사선 치료 시 용적변조와 세기변조방사선치료계획 비교 평가)

  • Jung, hae youn;Seok, jin yong;Hong, joo wan;Chang, nam jun;Choi, byeong don;Park, jin hong
    • The Journal of Korean Society for Radiation Therapy
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    • v.27 no.1
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    • pp.45-52
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    • 2015
  • Purpose : The dose distribution of organ at risk (OAR) and normal tissue is affected by treatment technique in postoperative radiation therapy for prostate cancer. The aim of this study was to compare dose distribution characteristic and to evaluate treatment efficiency by devising VMAT plans according to applying differed number of arc and IMRT plan for postoperative patient of prostate cancer radiation therapy using a rectal balloon. Materials and Methods : Ten patients who received postoperative prostate radiation therapy in our hospital were compared. CT images of patients who inserted rectal balloon were acquired with 3 mm thickness and 10 MV energy of HD120MLC equipped Truebeam STx (Varian, Palo Alto, USA) was applied by using Eclipse (Version 11.0, Varian, Palo Alto, USA). 1 Arc, 2 Arc VMAT plans and 7-field IMRT plan were devised for each patient and same values were applied for dose volume constraint and plan normalization. To evaluate these plans, PTV coverage, conformity index (CI) and homogeneity index (HI) were compared and $R_{50%}$ was calculated to assess low dose spillage as per treatment plan. $D_{25%}$ of rectum and bladder Dmean were compared on OAR. And to evaluate the treatment efficiency, total monitor units(MU) and delivery time were considered. Each assessed result was analyzed by average value of 10 patients. Additionally, portal dosimetry was carried out for accuracy verification of beam delivery. Results : There was no significant difference on PTV coverage and HI among 3 plans. Especially CI and $R_{50%}$ on 7F-IMRT were the highest as 1.230, 3.991 respectively(p=0.00). Rectum $D_{25%}$ was similar between 1A-VMAT and 2A-VMAT. But approximately 7% higher value was observed on 7F-IMRT compare to the others(p=0.02) and bladder Dmean were similar among the all plan(P>0.05). Total MU were 494.7, 479.7, 757.9 respectively(P=0.00) for 1A-VMAT, 2A-VMAT, 7F-IMRT and at the most on 7F-IMRT. The delivery time were 65.2sec, 133.1sec, 145.5sec respectively(p=0.00). The obvious shortest time was observed on 1A-VMAT. All plans indicated over 99.5%(p=0.00) of gamma pass rate (2 mm, 2%) in portal dosimetry quality assurance. Conclusion : As a result of study, postoperative prostate cancer radiation therapy for patient using a rectal balloon, there was no significant difference of PTV coverage but 1A-VMAT and 2A-VMAT were more efficient for dose reduction of normal tissue and OARs. Between VMAT plans. $R_{50%}$ and MU were little lower in 2A-VMAT but 1A-VMAT has the shortest delivery time. So it is regarded to be an effective plan and it can reduce intra-fractional motion of patient also.

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Effect of pH on the Extraction Characteristics of Succinic and Formic Acids with Tri-n-octylamine Dissolved in 1-Octanol

  • Hong, Yeon-Ki;Hong, Won-Hi;Chang, Yong-Keun
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.6 no.5
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    • pp.347-351
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    • 2001
  • A study was made on the extraction equilibria of succinic and formic acids from aqueous solutions using tri-n-octylamine (TOA) in 1-octanol. It was shown that the loading values of TOA decreased with increasing pH values. The apparent equilibrium constants for each acidamine complex were determined by an equilibrium model. In the case succinic acid, the formation of a bisuccinate anion played an important role in the stoichiometry of the acid-amine complex.

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Characterization of Tetracycline Resistant Plasmid in Staphylococcus aureus by Restriction Enzyme Mapping (황색포도상구균에서 테트라사이클린 내성을 나타내는 플라스미드의 동정)

  • Kim, Ki-Hyun;Kim, Jong-Myung;Moon, Kyung-Ho
    • YAKHAK HOEJI
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    • v.36 no.3
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    • pp.255-258
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    • 1992
  • The clinical isolate Staphylococcus aureus SA8 was resistant to tetracycline(Tc) and harboured a plasmid pKH1(24.82 kb). pKH1 was shown by curing and by transformation to specify resistance to Tc. The cleavage map of a pKH1 was determined by restricction enzyme mapping techniques. Cleavage map is given for BglII, EcoRI, HpaII, PvuII and SalI. Restriction endonuclease BamHI, BglI, BstEII, HpaI, PstI, and XhoI have no sites on this plasmid. HaeIII, XbaI, and HindIII have 5, 6, 14 sites, respectively.

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Synthesis and Characteristics of New Poly(p-phenylenevinylene) with Bulky t-Octylphenoxy Group

  • Kim, Yun-Hi;Lee, Hyun-Ouk;Jung, Sung-Ouk;Kwon, Soon-Ki
    • Macromolecular Research
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    • v.11 no.3
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    • pp.194-197
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    • 2003
  • A new 2,5-di(t-octylphenoxy) group substituted poly(p-phenylenevinylene) derivative was synthesized by Gilch polymerization. The obtained polymer was characterized by NMR, FT-IR, and chemical analysis and completely soluble in common organic solvents. The polymer showed good thermal stability with T$_{g}$ of 105$^{\circ}C$. The polymer dissolved in chloroform showed maximum emission at 514 nm with a shoulder peak at around 560 nm. The EL spectrum of the ITO/PEDOT/TOP-PPV/Al device was observed maximum emission at 545 nm with a shoulder peak at around 585 nm.m.