• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.2981-2987
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• 2011

A comparative study of the photodynamic and antioxidant activities of methyl pheophorbide-a (MPa, 1) and its transition metal(II) complexes (2-5) is described. Four transition metal complexes (palladium(II): 2, zinc(II): 3, cobalt(II): 4 and copper(II): 5) of MPa were prepared by reaction between the corresponding transition metal and 1, respectively, and were characterized by $^1H$-NMR and UV-vis spectroscopic and mass spectrometric analyses. In vitro results show a photodynamic therapy (PDT) efficacy with A549 cells might be attributed to a heavy atom effect of the transition metal complexes of MPa. Among them, 4 and 5 showed higher photodynamic activity than that of 1 at the concentration of 5 ${\mu}M$ at 24 h incubation after photoirradiation. The images of morphological change for 2-5 show evidence for the PDT effect with A549 cells. And the all transition metal complexes of MPa showed higher antioxidant activity than that of MPa, in which 4 showed the highest antioxidant activity.

• Journal of Nutrition and Health
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• 제48권5호
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• pp.451-456
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• 2015

Purpose: Neuronal apoptotic events induced by aging and hypoxic/ischemic conditions is an important risk factor in neurodegenerative diseases such as ischemia stroke and Alzheimer's disease. The peel of Citrus sunki Hort. ex Tanaka has long been used as a traditional medicine, based on multiple biological activities including anti-oxidant, anti-inflammation, and anti-obesity. In the current study, we examined the actions of fermented C. sunki peel extract against cobalt chloride ($CoCl_2$)-mediated hypoxic death in human neuroblastoma SH-SY5Y cells. Methods: Cell viability was measured by trypan blue exclusion. Expression of apoptosis related proteins and release of cytochrome c were detected by western blot. Production of intracellular reactive oxygen species (ROS) and apoptotic morphology were examined using 2',7'-dichlorofluorescin diacetate (DCF-DA) and 4',6-diamidino-2-phenylindole (DAPI) staining. Results: Exposure to $CoCl_2$, a well-known mimetic agent of hypoxic/ischemic condition, resulted in neuronal cell death via caspase-3 dependent pathway. Extract of fermented C. sunki peel significantly rescued the $CoCl_2$-induced neuronal toxicity with the cell viability and appearance of apoptotic morphology. Cytoprotection with fermented C. sunki peel extract was associated with a decrease in activities of caspase-3 and cleavage of poly (ADP ribose) polymerase (PARP). In addition, increase in the intracellular ROS and release of cytochrome c from mitochondria to the cytosol were inhibited by treatment with extract of fermented C. sunki peel. Conclusion: Based on these data, fermented C. sunki peel extract might have a protective effect against $CoCl_2$-induced neuronal injury partly through generation of ROS and effectors involved in mitochondrial mediated apoptosis.

• 한국초지조사료학회지
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• 제36권3호
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• pp.191-198
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• 2016

This study evaluated the effects of TMC (trace mineral-fortified microbial culture) supplementation on growth performance, carcass characteristics, and meat quality parameters of Hanwoo steers during the last 4 months of finishing period. The TMC was a combination of 0.4% trace minerals, 20.0% Na-bentonite, and 79.6% feedstuffs, which was inoculated with a mixed microbial culture (Enterobacter ludwigii, Bacillus cereus, B. subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae). Twenty-four steers were blocked by initial BW ($634{\pm}16kg$) and randomly allocated to one of two treatments (control vs. 3.3% TMC). The effect of TMC supplementation on the growth performance was not significant. There was no incidence of urolithiasis in TMC-fed steers. However 3 out 12 steers (25%) fed the control diet were observed to have urinary calculi. The carcass yield and meat quality parameters were not affected by TMC supplementation, however marbling score was increased in TMC-fed steers (P = 0.08). There was no effect of TMC treatment on the chemical composition of longissimus dorsi muscle (LM). The TMC supplementation increased concentrations of manganese (P < 0.01), cobalt (P = 0.02), iron, and copper (P = 0.06) in LM. In conclusion, TMC treatment did not negatively affect growth performance and meat quality parameters, and positively affected the trace minerals profile of LM.

• 소성∙가공
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• 제8권3호
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• pp.247-247
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• 1999

The segregation (distribution) of nickel and the composition of its constituents influence the low thermal expansion characteristics (Invar effect) in Fe-30 wt.% Ni-12.5 wt.% Co-xC Invar alloy. The change of coefficient of the thermal expansion and magnetic properties were studied as an aspect of carbon addition causing the segregation of Ni in primary austenite of as-cast Fe-30 wt.% Ni-12.5 wt.% Co Invar alloy. The coefficient of thermal expansion of Fe-30 wt.% Ni-12.5 wt.% Co-xC Invar alloy showed its lowest value at 0.08 wt.% carbon, increased with increasing carbon content in the range of 0.08-1.0 wt.%C, kept constant at 1.0-2.0 wt.%C and decreased at carbon higher than 2.0 wt.%. The effective distribution of the coefficient of nickel in as-cast Fe-30 wt.% Ni-12.5 wt.% Co-xC Invar alloy increased with increasing carbon content. The volume fraction of they phase of Fe-30 wt.% Ni-12.5 wt.% Co-xC alloy increased with increasing carbon content. The microstructure of Fe-30 wt.% Ni-12.5 wt.% Co-xC alloy changed with the carbon content was independent of the coefficient of thermal expansion. The Curie temperature changed linearly with the carbon content and was similar to the change of the coefficient of thermal expansion. Moreover, the coefficient of thermal expansion decreased when the ratio of saturation magnetization to Curie temperature ($\sigma_s/T_c$) increased, decreasing the Curie temperature and showed a specific relationship with the magnetic properties of the Fe-30 wt.% Ni-12.5 wt.% Co-xCInvar alloy.

• 대한화학회지
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• 제31권1호
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• pp.37-44
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• 1987

몇가지 이성분 혼합용매(물-메틸알코올, 물-아세톤, 물-이소프로필알코올, 물-에틸렌글리코올)에서 $cis-[Co(en)_2Cl_2]^+$착이온의 가용매분해반응속도를 분광광도법을 이용하여 압력(1~1500bar)에 따라 측정하였다. 속도상수에 대한 압력의 영향으로부터 구한 활성화체적은 메틸알코올, 아세톤, 이소프로필알코올, 에틸렌글리코올에서 각각 1.13∼4.44, 1.13~3.59, 0.82~3.44, 1.13~2.68cm3mole-1이었다. 또한 메틸알코올에서는 촉매제로 Fe(Ⅱ)이온을 사용하여 가용매분해반응속도를 측정하였고, 활성화체적은 -0.56∼1.59cm3mole$^{-1}$이었다. 가용매분해반응성은 자유에너지변화사이클과 활성화체적을 이용하여 고찰하였다.

• 방사선산업학회지
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• 제5권2호
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• pp.169-173
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• 2011

This study investigated the effect of gamma irradiation on immune enhancing activity of Chaga mushroom extract (CME). CME was prepared by hot water extraction at $70^{\circ}C$ for 4 hours and lyophilized. Lyophilized CME powder was dissolved with deionized water at $10mg\;ml^{-1}$ and then irradiated at the doses of 10, 30 and 50 kGy by cobalt 60 gamma irradiator. The gamma-irradiated and non-irradiated CME were treated into the splenocyte separated from mouse. Cell proliferation and cytokine production of the immune cells were increased by gamma-irradiated CME and these increases were more prominent when CME was irradiated at higher doses. Therefore, it is considered that gamma irradiation can be an effective method for improvement of the immunomodulating activity Chaga mushroom extract.

• 약학회지
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• 제38권5호
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• pp.614-620
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• 1994

Following the study on the fermentation conditions influencing the production of vitamin $B_{12}$ by Propionibacterium shermanii(Korean J Biotechnol. Bioeng. 7,126-131, 1992), the effects of some factors supplemented in the medium on the production of vitamin $B_{12}$ were studied. Maximum production of vitamin $B_{12}$ was observed when $Co^{+2}$ was supplemented at the concentration of 2-4 ppm in the fermentation medium. Increase of the supplemented $Co^{+2}$ to 12 ppm did not inhibit the growth of the organism, but it accelerated the lysis of the organism. In the literature, peptone was reported to activate the biosynthesis of vitamin $B_{12}$. Examination of the effect of peptone on the growth and the production of vitamin $B_{12}$ showed that at early stage more vitamin$B_{12}$ was observed in the supplemented medium, but no difference was observed in the later stage of fermentation. Examination of the time for addition and the amount of 5,6-dimethylbenzimidazole, a precursor known to influence the production of vitamin $B_{12}$, showed that a maximum yield of vitamin $B_{12}$ was observed when 15 mg/L was added to the fermentation medium after 2 days' incubation. The effect was comparable with the increase of the production of vitamin $B_{12}$ when the fermentation condition was changed to aerobic condition after 2 days' culture under anaerobic condition.

• Korean Chemical Engineering Research
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• 제56권6호
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• pp.895-900
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• 2018

본 연구에서는 Co-B, Co-W-B 합금 박막 형성을 위한 무전해 전착법을 고안하고, 이를 통해 형성한 합금 박막의 B과 W의 함량이 박막의 경도에 미치는 영향을 살펴보았다. 무전해 전착을 통해 무정형 상태의 Co 합금 박막을 성공적으로 형성할 수 있었으며, 환원제인 dimethylamine borane과 W의 원료인 sodium tungstate dihydrate의 농도를 조절함으로써 Co 합금 박막 내 혼합되는 B과 W의 함량을 조절하였다. 이를 통해 Co 합금 박막 내 전위(dislocation)의 전파(propagation)를 억제하는 B과 W의 함량이 증가할수록 박막의 경도가 증가함을 확인할 수 있었다. 뿐만 아니라, 무전해 전착 시 포기(aeration)를 수행하지 않을 경우에 포기를 수행한 경우보다 Co 합금 박막 내 B과 W의 함량을 대폭 증가시킬 수 있었고 최종적으로 Co-W-B 합금 박막의 경도를 8.9 (${\pm}0.3$) GPa까지 향상시켰다.

• 한국산업보건학회지
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• 제32권3호
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• pp.253-267
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• 2022

Objectives: This study was performed to check whether the CRS (Chemical Ranking and Scoring) system is appropriate as a method to determine substances as candidates for substances subject to permission and to apply this system to the selection of candidates for substances subject to permission. Methods: A risk score was obtained by multiplying the hazard score and the exposure score and then ranking them. The hazard sub-indicators are carcinogenicity, germ cell mutagenicity, reproductive toxicity, specific target organ toxicity-repeated exposure, respiratory sensitization and endocrine disrupting chemicals. Exposure sub-indicators are persistence, bioaccumulation and emission volume. Sensitivity analysis was performed for missing values. Correlation analysis and multivariable linear regression analysis were performed among hazard, exposure and risk in order to confirm that CRS was an appropriate method. Results: As a result of the sensitivity analysis on missing values, it was confirmed that the effect on the risk ranking was not sensitive. Correlation and regression analysis confirmed that exposure had a greater effect on risk than hazard. Conclusions: The CRS system, which derives a risk score using a hazard and exposure score, is judged to be appropriate as a method for the selection of preliminary of candidates for substances subject to permission. Benzene, cadmium, nickel, and cobalt were selected as priority candidates for substances subject to permission.

• 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.