• Radiation Oncology Journal
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• 제16권3호
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• pp.225-231
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• 1998

목적 : 마우스 동종암에 TNF-$\alpha$와 방사선을 병용하여 방사선의 항암 효과가 TNF-$\alpha$에 의하여 증강될 수 있는지 연구하고자 하였다. 대상 및 방법 : C3Hf/HeJ 마우스에 유방암인 MCa-K, MCa-4, 난소암인 OCa-I, 그리고 간암인 HCa-I 등 종양을 이식하였다. 종양의 크기가 6 mm에 이를 때 TNF-$\alpha$, 방사선, 또는 병용군 등 실험군을 나누어 적절한 치료를 하였다. 방사선조사는 Cobalt-60 방사선 조사기를 이용하여 HCa-I 에는 30 Gy를, 나머지 종양에는 15 Gy를 단일 조사하였다. TNF-$\alpha$는 실험실 마우스당 하루 10 ug씩 7일간 연속 주사하였다. 치료 결과는 종양성장지연 분석법으로 평가하였다. 결과 : TNF-$\alpha$ 단독 투여시 네가지 종양 중 MCa-K 및 OCa-I 종양에서 absolute growth delay (AGD)가 각각 5.0일, 6.5일로 유의한 항암 효과가 있었다. TNF-$\alpha$와 방사선을 병용한 경우 OCa-I에서는 AGD가 TNF-$\alpha$ 단독의 6.5일, 방사선의 26.9일에 비하여 TNF-$\alpha$와 방사선 병용시 41.1일로 의의있게 증가하였다 (p<0.05). EF는 1이상으로서 (EF: 1.29) TNF-$\alpha$와 방사선 병용시 증강효과가 있는 것으로 나타났다. 나머지 세 종양에서는 TNF-$\alpha$ 단독 및 방사선 단독에 비하여 TNF-$\alpha$와 방사선 병용시 AGD의 유의한 증가는 관찰되지 않았다. 결론 : TNF-$\alpha$는 마우스 동종암 중 일부 종양 (MCa-K 및 OCa-I)에서 항암 효과를 보였다. 방사선과 병용한 경우에도 일부 종양에서만 (OCa-I) 방사선의 항암 효과를 증강시키는 것으로 나타났다. 이같이 종양에 따라 방사선과 TNF-$\alpha$의 병용치료 효과의 정도가 다르다는 점은 향후 임상적 적용에 대비한 유용한 기초자료로 쓰일 것으로 기대된다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권2호
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• pp.189-197
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• 2003

Soluble glass bolus with selenium (Se), copper (Cu) and cobalt (Co) was administered intraruminally to Philippine grazing does fed under backyard farming conditions to determine its effect on blood mineral status. Forty-five does were dosed with SGB intraruminally every 6 months, whereas 15 were without SGB during this experimental period of 10 months. Blood of does in both treatment groups were collected every other month and blood Se, plasma Cu, Ca, P and Mg were determined in this study. All does did not show clinical Se, Cu, Ca, P or Mg deficiency during this experimental period. Selenium concentration of treated does increased (p<0.01) after beginning of this experiment, whereas the level of control does decreased slowly (p<0.01). Two months after SGB administration, all treated does had higher blood Se than the lower limit of $20{\mu}g/l$ suggested by NRC (1981), whereas some control does had lower blood Se concentration than the lower limit of $20{\mu}g/l$. On the other hand, plasma Cu concentration of treated does started to increase more remarkably than control does 4 months after this experiment had started although the difference was insignificant. There were no significant differences between plasma Ca, P or Mg concentration of does in both treatment groups. Soluble glass bolus had no harmful effects on plasma macro mineral concentrations of grazing does. This study showed that SGB was available as mineral supplement to improve imbalances of selected mineral of grazing goats in the traditional backyard conditions in Luzon Island, Philippines.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2726-2732
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• 2014

The promoting effect of rhodium on the structure and activity of the supported Cu-Co based catalysts for CO hydrogenation was investigated in detail. The samples were characterized by DRIFTS, $N_2$-adsorption, XRD, $H_2$-TPR, $H_2$-TPD and XPS. The results indicated that the introduction of rhodium to Cu-Co catalysts resulted in modification of metal dispersion, reducibility and crystal structure. DRIFTS results of CO hydrogenation at reaction condition (P=2 MPa, $T=260^{\circ}C$) indicated the addition of 1 wt % rhodium improved hydrogenation ability of Cu-Co catalysts. The ethanol selectivity and CO conversion were both improved by 1 wt % Rh promoted Cu-Co based catalysts. The alcohol distribution over un-promoted and rhodium promoted Cu-Co based catalysts obeys A-S-F rule and higher chain growth probability was got on rhodium promoted catalyst.

• Carbon letters
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• 제17권1호
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• pp.53-64
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• 2016

Nitrogen (N)-doped ordered mesoporous carbons (OMCs) with a dual transition metal system were synthesized as non-Pt catalysts for the ORR. The highly nitrogen doped OMCs were prepared by the precursor of ionic liquid (3-methyl-1-butylpyridine dicyanamide) for N/C species and a mesoporous silica template for the physical structure. Mostly, N-doped carbons are promoted by a single transition metal to improve catalytic activity for ORR in PEMFCs. In this study, our N-doped mesoporous carbons were promoted by the dual transition metals of iron and cobalt (Fe, Co), which were incorporated into the N-doped carbons lattice by subsequently heat treatments. All the prepared carbons were characterized by via transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). To evaluate the activities of synthesized doped carbons, linear sweep was recorded in an acidic solution to compare the ORR catalytic activities values for the use in the PEMFC system. The dual transition metal promotion improved the ORR activity compared with the single transition metal promotion, due to the increase in the quaternary nitrogen species from the structural change by the dual metals. The effect of different ratio of the dual metals into the N doped carbon were examined to evaluate the activities of the oxygen reduction reaction.

• 자원리싸이클링
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• 제28권6호
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• pp.36-45
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• 2019

석유화학공정에서 발생하는 폐촉매는 바나듐, 몰리브덴, 니켈, 코발트와 같은 희유금속을 함유하고 있다. 유기산에 의한 상기 금속의 침출에 대해 연구하였다. 본 논문에서 사용한 유기산에 의한 금속의 침출률은 옥살산 > 타르타르산 > 구연산 > 말레산 > 오스코브르산 순서이었다. 상기 유기산은 바나듐과 몰리브덴의 침출에 선택성이 있으며 옥살산에 의한 침출률이 가장 높았다. 옥살산의 농도, 반응온도, 광액밀도, 교반속도를 변화시켜 옥살산에 의한 바나듐의 최적침출조건을 얻었다. 옥살산에 의한 바나듐의 침출에 대한 속도식을 조사한 결과 Avrami식과 잘 맞았으며 활성화에너지는 8.76 kJ/mol로 물질전달에 의해 침출반응이 율속되었다.

• 한국세라믹학회지
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• 제42권9호
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• pp.602-606
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• 2005

[ $LiCoO_{2}$ ] is the most common cathode electrode materials in Lithium-ion batteries. $LiCo_{0.97}Mg_{0.03}O_2$ was synthesized by the solid-state reaction method. We investigated crystal structures, electrical conductivities and electrochemical properties. The crystal structure of $LiCo_{0.97}Mg_{0.03}O_2$ was analyzed by X-ray powder diffraction and Rietveld refinement. The material showed a single phase of a layered structure with the space group R-3m. The lattice parameter(a, c) of $LiCo_{0.97}Mg_{0.03}O_2$ was larger than that of $LiCoO_2$. The electrical conductivity of sintered samples was measured by the Van der Pauw method. The electrical conductivities of $LiCoO_2$ and $LiCo_{0.97}Mg_{0.03}O_2$ were $2.11{\times}10^{-4}\;S/cm$ and $2.41{\times}10^{-1}\;S/cm$ at room temperature, respectively. On the basis of the Hall effect analysis, the increase in electrical conductivities of $LiCo_{0.97}Mg_{0.03}O_2$ is believed due to the increased carrier concentrations, while the carrier mobility was almost invariant. The electrochemical performance was investigated by coin cell test. $LiCo_{0.97}Mg_{0.03}O_2$ showed improved cycling performance as compared with $LiCoO_2$.

• International Journal of Oral Biology
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• 제31권1호
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• pp.15-20
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• 2006

Concerns remain regarding the biocompatibility and adverse effects of dental casting alloys. The aim of this study was to understand the cytopathogenic effect of metal ions, which might be released from dental alloys, on oral squamous carcinoma(OSC) cells. The cellular morphology, viability, the type of cell death and molecular change in response to metal ion salt solutions including aluminum(Al), cobalt(Co), copper(Cu) and nickel(Ni) were examined. The $TC_{50}$ values for the metal ions with the exception of AI were estimated to be between 400 and $600{\mu}M$. The cells treated with the metal ions showed apoptotic change with the exception of Al ions. Metal ion-induced apoptosis was further confirmed using flow cytometric analysis. This study showed that the cytotoxicity and the mode of cell death by metal ions clearly depend on the cell type, the type of metal ion and the duration of exposure. The protein level of Rb, a tumor suppressor that affects apoptosis para-doxically, was higher in the cells treated with Co, Cu and Ni. It is believed that apoptosis and cell damage in the OSC cells treated with Co, Cu or Ni can be evoked by the regulation of Rb.

• 한국결정성장학회지
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• 제12권2호
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• pp.87-90
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• 2002

$LiCoO_{2}$ powders were synthesized at various temperatures using lithium hydroxide and cobalt hydroxide as precursors prepared by precipitation process and freeze-drying. In this study, the$LiCoO_{2}$ samples were synthesized via a solid state reaction with various LiOH concentration between 10 % and 30 % excess. And $LiCoO_{2}$powders were calcined at 600~$800^{\circ}C$ in a short time. Measurements of XRD and SEM were performed to characterize the properties of the prepared materials. The effect of amount of Li ions on the structural change in powder has been examined using the XRD analysis. For the not added excess of LiOH, CoOOH phase presented in the XRD pattern of $LiCoO_{2}$ due to loss of Li ions during firing. The morphology and particle size of the powders were examined using SEM. The obtained powders are high temperature-$LiCoO_{2}$HT-LiCoO$_{2}$) and homogeneous with the range of grain size in the order of hundreds of nanometers. The effects of variation of LiOH concentration on the structural change in powder were investigated using the Rietveld analysis. As an analysis result, c/a is constant by 4.99 on all occasions. Finally, the structure of HT-$LiCoO_{2}$ was simulated by the commercial software $Creius^{2}$(Molecular Simulations, Inc.) from the results of Rietveld analysis.

• 한국재료학회지
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• 제26권5호
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• pp.250-257
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• 2016

Octahedral $Co_3O_4$/carbon nanofiber (CNF) composites are fabricated using electrospinning and hydrothermal methods. Their morphological characteristics, chemical bonding states, and electrochemical properties are used to demonstrate the improved photovoltaic properties of the samples. Octahedral $Co_3O_4$ grown on CNFs is based on metallic Co nanoparticles acting as seeds in the CNFs, which seeds are directly related to the high performance of DSSCs. The octahedral $Co_3O_4$/CNFs composites exhibit high photocurrent density ($12.73mA/m^2$), superb fill factor (62.1 %), and excellent power conversion efficiency (5.61 %) compared to those characteristics of commercial $Co_3O_4$, conventional CNFs, and metallic Co-seed/CNFs. These results can be described as stemmnig from the synergistic effect of the porous and graphitized matrix formed by catalytic graphitization using the metal cobalt catalyst on CNFs, which leads to an increase in the catalytic activity for the reduction of triiodide ions. Therefore, octahedral $Co_3O_4$/CNFs composites can be used as a counter electrode for Pt-free dye-sensitized solar cells.

• 대한예방한의학회지
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• 제4권2호
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• pp.25-56
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• 2000

Trace element are involved in enzymatic activities, immunological reactions. physiological mechanisms. Deficiency in some trace elements, such as iron and iodine. is still an important health problem, The role of trace elements deficiency is suspected in various clinical situations and is now confirmed by well designed supplementation studies. However, the importance of trace elements as chinese herbal constituents is not sufficiently appreciated by the oriental medical profession, although in recent years a significant increase of new finding on their essential character in chinese herbal medicine occurred. It is well known that herbal medicine contains a variety of trace elements which would show therapeutic effects with active components in herbal medicine . In china, recent work showed some positive correlation between trace element and traditional chinese medicine (TCM) in terms of therapeutic effects even if their role in therapeutic effects is still obscure. In korea, not much attention has been on the therapeutic importance of trace element contained in herbal medicine Here, the therapeutic effects of trace element in TCM were reviewed and summarized. 1. Iron, copper, zinc and manganese are mainly contained in TCM. In addtion, chromium, magnesium, molybdenum, nickel, alminium, cobalt, arsenic and selenium has been studied for their therapeutic effects 2. Zinc, is decreased in patients who have deficiency of kindney(腎虛) and chronic disease. Fe is decreased in patients who have deficiency of blood(血虛). However copper is increased in patients who have chronic disease and hepatic disease.3 Iron concentration is high in herbs used for tonifying and nourishing yin or blood(補陰補血藥) Zinc concentration is high also in herb used for tonifying kidiney and vital essence(補腎補精藥). In addition. copper concentration Is high in herb used for replenishing qi(補氣藥) 4 In herbal drugs, the therapeutic substances in TCM are not only organic but also inorganic. It seems that trace elements would be one of components in herb for its therapeutic effects. This indicates that therapeutic effects of TCM should be extended not only to herb itself, bur also to trace elements contained in herb.