• 제목/요약/키워드: F and $F^{+}$-Center

검색결과 4,102건 처리시간 0.038초

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

  • 김경덕;김강웅;배기민;손맹현;안철민
    • 한국수산과학회지
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    • 제45권5호
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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
    • 대한방사성의약품학회지
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    • 제1권1호
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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

  • 이정철;정연식;김석기;윤경훈;송진수;박이준;권성원;임광수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 C
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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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메페남산 캅셀의 용출에 미치는 계면활성제의 영향 (Effect of Surfactants on Dissolution Rate of Mefenamic Acid Capsules)

  • 전영빈;김승인;김영일
    • Journal of Pharmaceutical Investigation
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    • 제20권3호
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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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    • 제24권6호
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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.

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

  • 조혜린;황민성;이영진;정재엽
    • 한국결정성장학회지
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    • 제33권5호
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    • pp.181-186
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    • 2023
  • 본 연구에서는 containerless processing 법을 활용하여 새로운 형광 소재용 Eu2O3-BaF2-La2O3-B2O3 계 유리 및 결정화 유리를 개발하였다. 또한 조성 및 결정화 정도에 따른 유리의 열적, 광학적, 구조적 특성 변화를 분석하였다. 유리 조성에 따른 열적 특성은 DTA 분석을 통해 이루어졌으며, BaF22 함량의 증가에 따라 유리전이온도 및 유리화능이 급격히 감소하는 것을 확인하였다. 유리의 결정화 특성은 XRD 분석을 통해 확인되었으며, BaF2 결정상의 결정화 정도에 따라 발광 효율이 증가하는 것을 확인할 수 있었다. 유리구조 내에서 fluorine 이온의 결합특성을 분석하기 위해 La 3d5/2 XPS 및 F 1s XPS 스펙트럼을 분석하였다. fluorine 이온은 유리내에서 network modifier 역할을 하는 Ba2+ 및 La3+ 이온과 주로 결합하는 것을 확인할 수 있었고, 결정화 과정에서 La-F 결합이 감소하고 Ba-F 결합이 증가하는 것을 확인할 수 있었다.

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

  • 김상은;최연성;지대윤;이경한;최용;김병태
    • 대한핵의학회지
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    • 제31권4호
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    • pp.421-426
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    • 1997
  • [$^{18}F$]FMBS는 도파민 $D_2$ 수용체 방사성추적자로서 유망한 성질을 지니고 있다. [$^{18}F$]FMBS는 비교적 높은 특이결합/비특이결합 비를 제공하며, 그 체내결합은 도파민 $D_2$ 수용체에 대하여 높은 특이성과 선택성을 보인다. 도파빈 $D_2$ 수용체 측정을 위한 보다 적합한 PET 방사성추적자를 얻기 위해서는 [$^{18}F$]FMBS의 낮은 뇌섭취와 느린 역학을 개선할 수 있는 화학적 구조의 변형이 시도되어야 하며, [$^{18}F$]FMBS는 이러한 시도의 골격이 될 수 있을 것으로 믿는다.

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

  • 장동근;양승오;이상호;배종림;김정구
    • 대한방사선기술학회지:방사선기술과학
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    • 제35권2호
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    • pp.151-156
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    • 2012
  • $^{18}F$-fluorodeoxyglucose ($^{18}F$-FDG)는 상당한 양의 방사능이 신장과 비뇨기계에 저류 되어 영상의 질을 저하시키고 진단 성능을 저하시킨다. 이러한 $^{18}F$-FDG의 비뇨기계 저류를 막기 위해 이뇨제를 사용하여 검사를 진행하게 된다. 이때 사용되는 이뇨제가 영상에 미치는 영향과 $^{18}F$-FDG 배설률에 미치는 영향을 알아보고자 하였다. PET/CT 검사를 시행한 환자 중 신장의 원발성 종양 또는 전이 병변이 없는 환자를 대상으로 $^{18}F$-FDG와 함께 이뇨제를 주사한 그룹, 생리식염수를 주사한 그룹, $^{18}F$-FDG만을 주사 한 정상군 그룹으로 진행하였으며, 각 그룹의 관심영역을 설정하여 SUV를 측정하였다. 또한 정량적 분석을 위하여 $^{18}F$-FDG를 주사 후 이뇨제 투여 여부에 따른 SUV를 비교 평가하였다. SUV 측정에 따라 영상의 배후방사능이 감소된 영상을 얻을 수 있었으며 이뇨제 사용으로 배설된 소변의 양이 늘어났지만, 소변에 방사능량의 변화가 없는 상반된 결과가 나타났다. 따라서 이뇨제가 영상의 배후방사능을 줄일 수는 있지만 $^{18}F$-FDG 배설에는 영향을 미치지 못함을 확인 하였다.

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

  • 박준형;임기섭;이홍진;정경일;이병철;이인원
    • 핵의학기술
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    • 제13권3호
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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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일개 시 보건소에 등록된 재가노인의 일상생활 동작수행 정도에 대한 조사연구 (A Study on the Level of ADL in Community Dwelling Elderly Registered in a Public Health Center)

  • 김금자;장효순;윤진;고선화;이은희
    • 지역사회간호학회지
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    • 제13권2호
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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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