• 한국토양비료학회지
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• 제30권4호
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• pp.370-376
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• 1997

우리나라에서 가장 많이 소비되고 있는 채소중의 하나인 무를 실험종으로 선택하여 토양중 크롬의 농도, 토양 pH, 공존중금속 첨가, 복토, 유기물처리의 요인을 변수로 하여 무의 생육상태 및 무에 의한 크롬의 흡수이행량 차이를 조사하였다. 무종자의 발아율은 크롬농도 50mg/kg에서는 발아에 영향이 없었으나 100% 이상이었으며, 250mg/kg에서는 63% 정도의 발아율을 나타내었다. 토양중에 처리된 크롬농도가 증가할수록 무의 초장, 근장, 건물량이 감소하는 경향이었으며 크롬농도 100mg/kg 까지는 대조구와 비슷하게 생육하였으나 크롬농도 250mg/kg에서 건물량의 약 45%의 생육저해가 나타났다. 토양 pH가 증가함에 따라 무로 흡수이행되는 크롬의 함량이 감소하는 역의 상관을 나타내었으며(줄기: $r=-0.803^*$, 뿌리: $r=-0.840^*$) Fe, Zn, Cu와 같은 공존이온 첨가시 무의 생육 및 흡수이행되는 크롬함량간에 유의성이 인정되지 않았다(줄기, 뿌리 P>0.1). 복토, 유기물처리를 하였을 경우 대조구에 비하여 생육상태가 진전되었으며, 복토처리시 무로의 흡수이행량은 큰 차이를 나타내지 않은 반면에 유기물 처리시 무로 흡수이행되는 크롬의 함량이 감소하는 경향이었다.

• 한국잠사곤충학회지
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• 제38권1호
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• pp.25-30
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• 1996

견 피브로인 섬유에 의한 Cr(VI)의 흡착 특성을 분석하였다. Cr(VI)의 흡착평형은 초기 흡착속도에 큰 영향을 받고 있으며 평형흡착량의 52% 정도에 이르고 있다. 견 피브로인 섬유에 의한 Cr(VI)의 흡착은 크롬염의 산화반응을 일으키는 산성의 pH 범위에서 흡착량이 증가한다. Cr(VI)의 흡착온도에 대한 엔탈피($\Delta$H)의 변화는 39.7KJ.mol-1로 얻어졌다. 이것은 Cr(VI)의 흡착이 착제 화학적 반응이라는 것을 의미하며 IR 스펙트럼의 결과에서도 아미드 형 카르보닐의 배위에 의한 착물형성이 확인되었다. 또한, 견 피브로인 섬유의 크롬 흡착처리에서 물성의 과도한 저하를 고려한 조건은 온도 5$0^{\circ}C$ pH 2.4, 3시간의 처리가 적당하고 5 X 10-3M의 농도에서 흡착평형에 도달하였다.

• 한국환경과학회지
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• 제21권3호
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• pp.369-375
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• 2012

We investigated usefulness of chicken feather as bioadsorbent for removal of hexavalent chromium[Cr(VI)] and oil from aqueous solution. Chicken feather was chemically treated with DTPA, EDTA, NaOH and SDS, respectively. Among them, EDTA was the most effective in adsorbing Cr(VI). Cr(VI) uptake by chicken feather was increased with decreasing pH; the highest Cr(VI) uptake was observed at pH 2.0. By increasing Cr(VI) concentration, Cr(VI) uptake was increased, and maximum Cr(VI) uptake was 0.34 mmol/g. Cr(VI) adsorption by chicken feather was well described by Freundlich isotherm than Langmuir isotherm and Freundlich constant(1/n) was 0.476. As the concentration of chicken feather was increased, Cr (VI) removal efficiency was increased but Cr(VI) uptake was decreased. Most of Cr(VI) was adsorbed at early reaction stage(1 h) and adsorption equilibrium was established at 5 h. On the other hand, chicken feather adsorbed effectively oils including bunker-A and bunker-C. In conclusion, our results suggest that chicken feather waste could be used to remove heavy metal and oil; it is a potential candidate for biosorption material.

• 생약학회지
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• 제44권1호
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• pp.75-82
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• 2013

Previous studies have shown that Aloe QDM complex, which is consisted of chromium (Cr), aloesin (ALS) and processed Aloe vera gel (PAG), exert antidiabetic activity in a high fat diet-induced mouse model of type 2 diabetes. In this study we examined the mechanism of the antidiabetic activity of the Aloe QDM complex. Rat myoblast cell line L6 cells were cultured in the presence of Cr, ALS, and PAG alone and in combinations, and then the capability of the cells to uptake glucose was examined using radiolabeled glucose. All of the 3 agents, Cr, ALS and PAG, exerted glucose uptake-enhancing activity in L6 cells. The most potent capability to uptake glucose was observed when L6 cells were cultured with the Aloe QDM complex. The activity of the Aloe QDM complex to enhance glucose uptake was prominent in conditions where existing insulin concentrations are low. We also examined the effects of the Aloe QDM complex on the plasma membrane expression of GLUT4 in L6 cells. The Aloe QDM complex increased the content of GLUT4 in the plasma membrane, while decreasing the content of GLUT4 in the light microsome. Taken together, these results show that the antidiabetic activity of the Aloe QDM complex is at least in part due to the stimulation of glucose uptake into the muscle cells, and this activity of the Aloe QDM complex is mediated through the enhancement of the translocation of GLUT4 into the plasma membrane.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1211-1216
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• 2004

A MNNG (N-methyl-N'-nitro-N-nitrosoguanidine) induced chromium resistant strain ($Cr^{r}18$) of unicellular cyanobacterium Anacystis nidulans has been isolated and characterized. The resistant strain could grow (although restricted to $50\%$ of control) in chromium concentration (180${\mu}M$) lethal to the wild-type. Sublethal ($160{\mu}M$) concentration of $Cr^{6+}$ significantly reduced (13-$37.5$) all the photosynthetic pigments of A. nidulans with maximum reduction in phycoerythrin followed by ChI $\alpha$. Pigments of A. nidulans were drastically decreased in lethal concentration of Cr^{6+} with maximum reduction in phycoerythrin ($75\%$) and allophycocyanin ($67.5\%$). Resistant strain $Cr^{r}18$ resisted toxic effects of sublethal and lethal concentrations of $Cr^{6+}$ on photosynthetic pigments as revealed by less decrease in pigments as compared to A. nidulans. Effect of $Cr^{6+}$ stress was also studied on nitrogen assimilation and phosphate uptake. Sublethal concentration of $Cr^{6+}$ drastically reduced ($71.5\%$) nitrate uptake by A. nidulans while a decrease of $29\%$ was observed in strain $Cr^{r}18$. Short (2 day) exposure of A. nidulans and its resistant strain $Cr^{r}18\;to\;Cr^{6+}$ did not affect nitrate reductase and glutamine synthetase (transferase), whereas longer (10 day) exposure to $Cr^{6+}$ lowered activities of both enzymes in A. nidulans but not significantly in the strain $Cr^{r}18$. Ammonium uptake by both strains was not affected by $Cr^{6+}$. Thus, $Cr^{6+}$ affected photosynthetic pigments, nitrogen assimilation, and phosphate uptake of A. nidulans, while strain $Cr^{r}18$ was able to resist toxic effects of the metal. Advantages of using strain $Cr^{r}18$ for bioremediation purposes have been evaluated by studying $Cr^{6+}$ removal from the solution. Resistant strain $Cr^{r}18$ was able to remove $33\%$ more $Cr^{6+}$ than A. nidulans and thus it can prove to be a good candidate for bioremediation of $Cr^{6+}$ from polluted waters.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.692-698
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• 2005

Two experiments were conducted to examine the effect of graded levels of dietary chromium and leucine, and different fat sources on performance and body composition of broiler chickens. The results showed that chromium picolinate at 0.5 ppm significantly (p<0.05) lowered the carcass fat level. Gut weight and carcass water content were increased as a result of chromium treatment. Body weight, plucked weight, carcass weight, abdominal fat pad weight, breast yield and feed efficiency were unaffected by chromium treatment. Leucine did not interact with chromium to effect lean growth. Dietary leucine above the recommended maintenance level (1.2% of diet) markedly (p<0.001) reduced the breast muscle yield. The addition of fish oil to broiler diets reduced (p<0.05) the abdominal fat pad weights compared to birds on linseed diets. Fish oil is believed to improve lean growth through the effects of long chain polyunsaturated fatty acids in lowering the very low-density lipoprotein levels and triglyceride in the blood, in the meantime increasing glucose uptake into the muscle tissue in blood and by minimizing the negative impact of the immune system on protein breakdown. The amount of fat in the diet (2% or 4%) did not affect body composition.

• Journal of Ecology and Environment
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• 제38권2호
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• pp.123-131
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• 2015

During several visits to the Cebu City landfill in the Philippines, plants were observed growing within the area, including on top of the garbage piles. Studying the response of these plants is important in assessing which can be used in remediating metal contaminated soils. This study aimed to determine whether the plants in the Cebu City landfill excluded or accumulated cadmium (Cd) and chromium (Cr) in the plant tissues. The floristic composition of the landfill was analyzed prior to the sample collection. The samples were acid-digested before the desired elements were measured using atomic absorption spectrophotometry (AAS). The Cd and Cr concentrations in the plant root-zone soil were also measured using AAS. The results indicated that the landfill substrate was generally acidic based on the results of the pH measurement. Of the 32 plant species sampled, Cyperus odoratus showed potential for Cd uptake and internal transfer; Cenchrus echinatus, Vernonia cinerea and Terminalia catappa for Cr uptake, and Cynodon dactylon for Cr internal transfer. The plants in the landfill differed in their response towards the heavy metals. To confirm the behavior of C. odoratus towards Cd, and C. echinatus, C. dactylon, V. cinerea, and T. catappa towards Cr, controlled experiments are recommended, as the plant samples analyzed were collected from the field.

• Environmental Engineering Research
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• 제22권2호
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• pp.149-156
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• 2017

Chromium(III) recovery from tanning wastewater by means of adsorption on activated carbon and elution with sulfuric acid was studied. Tests were carried out at laboratory scale on an effluent of industrial origin. Initially, proteinaceous materials and fats were separated via sieving followed by ultrafiltration. The chemical composition of the sample thus precleansed was (in g/L): 1.09 chromium(III); 10.36 sulfate; 11.10 sodium; 9.57 chloride; 0.40 proteinaceous materials; and 0.20 fats. Adsorptions were made at 20, 30, and $40^{\circ}C$, establishing what temperature favored chromium(III) uptake. At $40^{\circ}C$, the maximum cation fixation was 40.2 mg/g, and the lowest content in an equilibrium solution was 3.9 mg/L. As regards sodium, chloride, and sulfate, the concentrations before and after the treatment were similar. Likewise, it was found that protons were also retained, modifying the pH of the liquid medium. Adsorption isotherms were analyzed using the Langmuir, Temkin, and Freundlich models. Finally, the extraction of the adsorbed tanning agent with sulfuric acid was evaluated. A recovery of 96.5% was achieved with 0.9 N at $70^{\circ}C$ (13.23 g/L $Cr^{3+}$; 42.98 g/L sulfate; and 0.40 g/L NaCl).

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.137-141
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• 2002

Anabaena variabilis ATCC 29413 grew in chromium (Cr) containing Chu-10 (basal) and nitrate-supplemented media, and the growth of the organism in $100{\mu}M$ chromium was found to be 50% of that in control medium. The growth in nitrate $({NO_3}^-)$ supplemented cultures was better as compared to cultures grown in basal medium. Free cells from basal and nitrate-supplemented media removed 5.2 and 7.4 nmol of chromium $mg^{-1}$protein in 8 h, respectively, from the medium containing $30{\mu}M$ chromium. The efficiency of chromium removal increased 7-fold in imidazole buffer (0.2 M, pH 7.0). A cell density equivalent to $100{\mu}g$ protein $ml^{-1}$ was found to be optimum for maximum Cr removal. Entrapment of cells in calcium-alginate beads did not affect the rate of Cr uptake by the cells. The efficiency of the laboratory-scale continuous flow bioreactor $(12.5{\times}2cm)$ loaded with alginate-immobilized cells (10 mg protein) and fed with $30{\mu}M$ chromium solution was compared at different flow rates. The efficiency of the bioreactor varied with flow rates. In terms of percent removal of Cr from influent, a flow rate of 0.1 ml $min^{-1}$ was found to be optimum for 6 h (54% Cr removal efficiency). Maximum amount of Cr (883 nmol) was removed by the cells in 3 h at a flow rate of 0.5 ml $min^{-1}$. The potential use of A. variabilis in removing Cr from industrial effluents is discussed.

• Fisheries and Aquatic Sciences
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• 제19권4호
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• pp.19.1-19.7
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• 2016

A laboratory experiment was conducted to determine hexavalent chromium ($Cr^{6+}$) accumulation in the mullet and investigate $Cr^{6+}$ toxicity using a panel of biomarkers including metallothioneins (MTs), glutathione (GSH), glutathione S-transferase (GST), and superoxide dismutases (SODs) for 4 weeks. $Cr^{6+}$ bioaccumulation in all tissues, except muscle, was consistently time- and dose-dependent. The accumulation of $Cr^{6+}$ for 4-week exposures was in the following order: $kidney{\approx}liver$ > $intestine{\approx}gill$ > spleen > muscle. Compared with the control, $Cr^{6+}$ bioaccumulation was increased in ${\geq}200{\mu}g\;L^{-1}$ groups (P < 0.05). An independent relation was observed between accumulation factors (AFs) and exposure concentration. But AFs increased with exposure time. In the liver and gill, GST and SOD differed from the control at a high $Cr^{6+}$ concentration at 2 and 4 weeks (P < 0.05). This study indicated that the gills were as sensitive as the liver to $Cr^{6+}$ toxicity. However, the latter appeared to influence largely on the organism's adaptive response to $Cr^{6+}$, since $Cr^{6+}$ may elevate GSH and MT levels by enhancing the hepatic uptake of metal in the mullet.