• Title/Summary/Keyword: F and $F^{+}$-Center

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Effects of Different Numbers of Feeding Days and Feeding Rate on Growth of Growing-out Flounder Paralichthys olivaceus (사료 공급일수 및 공급율이 육성기 넙치(Paralichthys olivaceus)의 성장에 미치는 영향)

  • Kim, Kyoung-Duck;Kim, Kang-Woong;Bae, Ki-Min;Son, Maeng Hyun;An, Cheul Min
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.5
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    • pp.523-526
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    • 2012
  • This study evaluated the effects of the number of feeding days and feeding rate on the growth of growing-out flounder Paralichthys olivaceus. Three replicated groups of fish ($141{\pm}1.9g$) were hand-fed a commercial feed under different feeding regimes for 9 weeks. Fish in group 6F-1S were fed to satiation twice daily for 6 consecutive days and starved for 1 day. Fish in groups 4F-1S and 3F-1S were fed to satiation twice daily for 4 and 3 days, respectively, and starved for 1 day. Fish in group 6F-90% were fed a diet of 90% of 6F-1S twice daily for 6 consecutive days and starved for 1 day. The weight gain, feed efficiency and daily feed intake of the fish groups in 4F-1S and 3F-1S were not significantly different from those of group 6F-1S. The weight gain and feed efficiency of fish in group 6F-90% were not significantly different from those of group 6F-1S. The results of this study suggest that the growth of growing-out flounder fed to satiation twice daily for 4 or 3 days after starving 1 day was similar to that of fish fed to satiation for 6 days, and that the proper feeding rate for growth could be lowered to 90% of satiation without growth suppression.

Synthetic approaches toward [18F]Fluoromisonidazole as a hypoxia imaging maker

  • Kwon, Young-Do;Lim, Seok Tae;Jeong, Hwan-Jeong;Sohn, Myung-Hee;Kim, Hee-Kwon
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.1 no.1
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    • pp.9-14
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    • 2015
  • Hypoxia has been shown in many tumors because of a reduced oxygen condition. A useful approach to detect hypoxia is to use molecular imaging. Positron emission tomography (PET), one of the biomedical molecular imaging tools, is the most common non-invasive technique for providing information about physiological and biological events such as diseases. In order to use the PET technique for healthcare, promising molecular probes such as PET tracers required. [$^{18}F$]Fluoromisonidazole ([$^{18}F$]FMISO) is the most widely used in PET tracers for hypoxia. In this review, major developments of the synthetic method of [$^{18}F$]FMISO are discussed.

Characterization of ${\mu}c$-Si:H Thin-film Solar Cells by Hot-wire CVD

  • Lee, J.C.;Chung, Y.S.;Kim, S.K.;Youn, K.H.;Song, J.S.;Park, I.J.;Kwon, S.W.;Lim, K.S.
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1598-1600
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    • 2003
  • Microcrystalline silicon(c-Si:H) thin-film solar cells are prepared with intrinsic Si-layer by hot wire CVD. The operating parameters of solar cells are strongly affected by the filament temperature ($T_f$) during intrinsic layer. Jsc and efficiency abruptly decreases with elevated $T_f$ to $1400^{\circ}C$. This deterioration of solar cell parameters are resulted from increase of crystalline volume fraction and corresponding defect density at high $T_f$ The heater temperature ($T_h$) are also critical parameter that controls device operations. Solar cells prepared at low $T_h$ (<$200^{\circ}C$) shows a similar operating properties with devices prepared at high $T_f$, i.e. low Jsc, Voc and efficiency. The origins for this result, however, are different with that of inferior device performances at high $T_f$. In addition the phase transition of the silicon films occurs at different silane concentration (SC) by varying filament temperature, by which highest efficiency with SC vanes with $T_f$.

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Effect of Surfactants on Dissolution Rate of Mefenamic Acid Capsules (메페남산 캅셀의 용출에 미치는 계면활성제의 영향)

  • Jun, Young-Bin;Kim, Seung-In;Kim, Young-Il
    • Journal of Pharmaceutical Investigation
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    • v.20 no.3
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    • pp.121-127
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    • 1990
  • Mefenamic acid has been widely used clinically as an anti-inflammatory analgesic. It has poor solubility in water $(41\;{\mu}g/ml)$ and there is the difficulty of dissolution in the mefenamic acid capsules. A study was made to investigate the effect of various surfactants on the dissolution of mefenamic acid capsules. The surfactants used were sodium lauryl sulfate (SLS), Pluronic F-68, F-77, and F-127. Mefenamic acid capsule containing surfactant showed significantly improved dissolution characteristics. The dissolution rate was fast in the order of SLS > F-77 > F-68 > F-127 in mefenamic acid capsules containing 0.2 w/w % surfactant. SLS was selected for further study on the bioavailability in rabbits. The area under the plasma concentration-time curve $(AUC_{0-24})$ of mefenamic acid capsule containing SLS was higher than one of mefenamic acid capsule not containing surfactant.

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Establishment of Tripterygium wilfordii Hook. f. Hairy Root Culture and Optimization of Its Culture Conditions for the Production of Triptolide and Wilforine

  • Zhu, Chuanshu;Miao, Guopeng;Guo, Jia;Huo, Yanbo;Zhang, Xing;Xie, Jiahua;Feng, Juntao
    • Journal of Microbiology and Biotechnology
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    • v.24 no.6
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    • pp.823-834
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    • 2014
  • In order to solve the shortage of natural Tripterygium wilfordii Hook. f. plant resource for the production of the important secondary metabolites triptolide and wilforine, hairy roots were induced from its root calli by Agrobacterium rhizogenes. Induced hairy roots not only could be maintained and grown well in hormone-free half-strength Murashige and Skoog medium but also could produce sufficient amounts of both triptolide and wilforine. Although hairy roots produced approximately 15% less triptolide than adventitious roots and 10% less wilforine than naturally grown roots, they could grow fast and could be a suitable system for producing both secondary metabolites compared with other tissues. Addition of $50{\mu}M$ methyl jasmonate (MeJA) could slightly affect hairy root growth, but dramatically stimulated the production of both triptolide and wilforine, whereas $50{\mu}M$ salicylic acid had no apparent effect on hairy root growth with slightly stimulatory effects on the production of both secondary metabolites. Addition of precursor nicotinic acid, isoleucine, or aspartic acid at the concentration of $500{\mu}M$ had varying effects on hairy root growth, but none of them had stimulatory effects on triptolide production, and only the former two had slightly beneficial effects on wilforine production. The majority of triptolide produced was secreted into the medium, whereas most of the produced wilforine was retained inside of hairy roots. Our studies provide a promising way to produce triptolide and wilforine in T. wilfordii hairy root cultures combined with MeJA treatment.

Development of novel oxyfluoride glasses and glass ceramics for photoluminescence material by a containerless processing (무용기 용융법을 활용한 형광소재용 결정화 유리 개발)

  • Hyerin Jo;Minsung Hwang;Youngjin Lee;Jaeyeop Chung
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.33 no.5
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    • pp.181-186
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    • 2023
  • In this study, novel Eu2O3-BaF2-La2O3-B2O3 oxyfluoride glasses and glass ceramics were developed by a containerless processing. Differential thermal analysis (DTA) analysis was performed to analyze the thermophysical properties of oxyfluoride glasses doped with Eu2O3, and photoluminescence (PL) characteristics were analyzed to evaluate the luminous efficiency depending on the degree of crystallinity. The glass transition temperature decreased with increasing BaF2 concentration since BaF2 acts as a network modifier in this glass system. In addition, thermal stability which can be estimated by the difference between the glass transition temperature and the onset temperature of the crystallization decreased with increasing BaF2 contents. The peak related to the BaF2 crystal was confirmed after the crystallization by X-ray Diffraction (XRD) analysis. Photoluminescence intensity increased after the crystallization which indicates that the Eu3+ ions are sited in BaF2 crystal. La 3d5/2 x-ray photoelectron spectroscopy (XPS) and F1s XPS spectra were analyzed to precisely understand the behavior of the fluorine ion in the glass structure. Fluorine tends to bond with the network modifying cations such as La3+ and Ba2+ ions and after the crystallization the La-F bonds decreased because F- ions used to form BaF2 crystals.

N-(4-[$^{18}F$]Fluoromethylbenzyl)spiperone : A Selective Radiotracer for In Vivo Studies of Dopamine $D_2$ Receptors (N-(4-[$^{18}F$Fluoromethylbenzyl)spiperone : 유력한 도파민 $D_2$ 수용체 선택성 방사성리간드)

  • Kim, Sang-Eun;Choe, Yearn-Seong;Chi, Dae-Yoon;Lee, Kyung-Han;Choi, Yong;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.31 no.4
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    • pp.421-426
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    • 1997
  • We evaluated the in vivo kinetics, distribution, and pharmacology of N-(4-[$^{18}F$]fluoromethylbenzyl)spiperone ([$^{18}F$]FMBS), a newly developed derivative of spiperone, as a potentially more selective radiotracer for the dopamine (DA) $D_2$ receptors. Mice received 1.9-3.7 MBq (1.8-3.6 nmol/kg) of [$^{18}F$]FMBS by tail vein injection. The time course and regional distribution of the tracer in brain were assessed. Blocking studies were carried out by intravenously preinjecting DA $D_2$ receptor blockers (spiperone, butaclamol) as well as drugs with high affinity for DA $D_1$ (SCH 23390), DA transporter (GBR 12909), and serotonin $S_2$ ($5-HT_2$) (ketanserin) sites. After injection of the tracer, the radioactivity in striatum increased steadily over time, resulting in a striatal-to-cerebellar ratio of 4.8 at 120 min postinjection. By contrast, the radioactivity in cerebellum, frontal cortex, and remaining cortex washed out rapidly. Preinjection of unlabeled FMBS (1 mg/kg) and spiperone (1 mg/kg) reduced [$^{18}F$]FMBS striatal-to-cerebellar ratio by 41% and 80%, respectively. (+)-Butaclamol (1 mg/kg) blocked 80% of the striatal [$^{18}F$]FMBS binding, while (-)-butaclamol (1 mg/kg) did not. Preinjection of SCH 23390 (1 mg/kg) and GBR 12909 (5 mg/kg) had no significant effect on [$^{18}F$]FMBS binding. Ketanserin (1 mg/kg), a ligand for the $5-HT_2$ receptors, did not cause significant inhibition either in striatum, in frontal cortex, or the remaining cortex. The results demonstrate that [$^{18}F$]FMBS labels DA $D_2$ receptors selectively in vivo in the mouse brain. It may hold promise as a selective radiotracer for studying DA $D_2$ receptors in vivo by PET.

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Characteristic of $^{18}F$-FDG Excretion According to Use Diuretics in $^{18}F$-FDG of PET/CT ($^{18}F$-FDG PET/CT 검사에서 이뇨제 사용여부에 따른 $^{18}F$-FDG 배설 특성)

  • Jang, Dong-Gun;Yang, Seoung-Oh;Lee, Sang-Ho;Bae, Jong-Lim;Kim, Jeong-Koo
    • Journal of radiological science and technology
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    • v.35 no.2
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    • pp.151-156
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    • 2012
  • $^{18}F$-fluorodeoxyglucose ($^{18}F$-FDG) causes a significant amount of radioactivity retention in kidneys and urinary tract and degrades image quality and diagnostic performance. Diuretics are used to perform tests and prevent the urinary tract retention of $^{18}F$-FDG. The purpose of the study is to investigate how the diuretics affect images and excretion rates of $^{18}F$-FDG. The study consists of a group using diuretics for patients with no primary tumors or transfer lesions in kidneys according to PET/CT images, a group using physiological saline and the control group injecting only $^{18}F$-FDG and SUVs are measured by configuring interested areas for each group. Also, SUVs are compared and evaluated depending on the lasix injection after basic inspection and injecting $^{18}F$-FDG for quantitative analysis. The study shows that images with decreased background radioactivity and increased urine excretion due to using diuretics. However, an opposite result that there is no change in the amount of radioactivity in urine appears. The study concludes that the diuretics may decrease background radioactivity in the images but may not affect the $^{18}F$-FDG excretion.

Improved Radiochemical Yields, Reliability and Improvement of Domestic $^{18}F$-FDG Auto Synthesizer (국산 $^{18}F$-FDG Auto Sysnthesizer의 수율 향상과 성능 개선)

  • Park, Jun-Hyung;Im, Ki-Seop;Lee, Hong-Jin;Jeong, Kyung-Il;Lee, Byung-Chul;Lee, In-Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.147-151
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    • 2009
  • Purpose: 2-[$^{18}F$]Fluoro-2-deoxy-D-glucose ([$^{18}F$]FDG) particularly plays as a important role in Positron Emission Tomography (PET) imaging in nuclear medicine. Domestic [$^{18}F$]FDG auto synthesizers are installed in Seoul National University Bundang Hospital (SNUBH) at June 2008, these modules were known that it's synthetic yields were guaranteed in average $45{\pm}5%$ so far. To improve yields and convenience of domestic [$^{18}F$]FDG auto synthesizer, numerous trials in reaction time, base concentration, pressure and temperature were performed to increase [$^{18}F$]FDG yields. Materials and Methods: Several synthetic factors (temperature, time and pressure) and shortcoming were corrected based on many evaporation test. Syringe dispensing of tetra-butylammonium bicarbonate (TBAB) was replaced with micro pipette to prepare tetrabutyl ammonium fluoride salt ([$^{18}F$]TBAF). Troublesome refill of liquid nitrogen every 2 hours which was used to protect vacuum system was changed to charcoal cartridge, base guard filter. To monitor the volume of delivered $[^{18}O]OH_2$ from cyclotron by surveillance camera, we set up the volumetric vial on the cover of the module. In addition to, the recovery vial was added in [$^{18}F$]FDG production system to recover [$^{18}F$]FDG loss due to the leak of valve ($V_{13,14}$) in [$^{18}F$]FDG purification process. Results: When we used micro pipette for adding TBAB ($30\;{\mu}L$ in 12% $H_2O$ in acetonitrile), this quantitative dispensation has enabled to improve $5.5{\pm}1.7%$ residual fluorine-18 activity in fluorine separation cartridge compared to syringe adding. Besides, the synthetic yields of [$^{18}F$]FDG has increased $58{\pm}2.6%$ (n=19), $58{\pm}2.9%$ (n=14), $60%{\pm}2.5%$ (n=17) for 3 months. The life cycle of charcoal cartridge and base vacuum was 3 months prior to filling liquid nitrogen every 2 hours and additional side separator can prevent pump corrosion by organic solvent. After setting of volumetric indicator vial, the operator can easily monitor the total volume of irradiated $[^{18}O]OH_2$ from cyclotron. The recovery vial can be used for the stabilizer when an irregular [$^{18}F$]FDG loss was generated by the leak of valves ($V_{13,14}$). Conclusions: We has optimized appropriate synthetic conditions (temperature, time, pressure) in domestic [$^{18}F$]FDG auto synthesizer. In addition to, the remodeling with several accessories improve yields of domestic [$^{18}F$]FDG auto synthesizer with reliable reproducibility.

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A Study on the Level of ADL in Community Dwelling Elderly Registered in a Public Health Center (일개 시 보건소에 등록된 재가노인의 일상생활 동작수행 정도에 대한 조사연구)

  • Kim, Keum-Ja;Jang, Hyo-Soon;Yoon, Jin;Ko, Sun-Hwa;Lee, Eun-Hui
    • Research in Community and Public Health Nursing
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    • v.13 no.2
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    • pp.332-342
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    • 2002
  • Purpose: The purpose of this study was to assess the level of activities of daily living (ADL) in a group of community dwelling elderly. Methods: The subjects were 100 low-income elderly registered in a public health center. The data were analyzed using the SPSS/PC program. Results: The results were as follows: 1. The basic ADLs of the subjects were scored at 7 levels, and the mean score was 6.24 out of 7 points. The subjects did not necessarily require help from others, but might have needed more times or instrumental assists to perform ADLs. The lowest ADL score was reported on walking up to the stairs (5.05), for which the subjects did not need physical assistance, but needed a certain degree of supervision. The highest score was reported on self eating (6.74), followed by bowel management (6.60). 2. The mean IADL score of the subjects was 1.77 out of 4 points. indicating that the subjects were very independent in performing IADLs, without help from others. 3. In relation to general characteristics, the level of ADLs of the subjects was significantly different by age (F=6.65, P=.000), main activities (F=6.36, P=.001), perceived health status (P=4.66, P=.012), educational background (F=4.64, P=.03), marital status(F=4.62, P=.005), and major household income (F=4.15, P=.002). 4. The subjects' level of IADLs in relation to their general characteristics was significantly different by perceived health status (F=8.08, P=.001), major activities (F=7.33, P=.000), age (F=6.18, P=.000), family context (F=3.53, P=.018), religion (F=3.10, P=.019), marital status(F=2.62, P=.055), and major household income (F=2.31, P=.049).

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