• Polymer(Korea)
• /
• v.39 no.2
• /
• pp.261-267
• /
• 2015

The inclusion complexes (ICs) between polylactic acid (PLA) and ${\beta}$-cyclodextrin (CD) were prepared by co-precipitation method in this work. The orthogonal experiments were designed to investigate the influence of different factors on the formation of inclusion complexes. The results suggested that the optimum scheme of inclusion compounds could be obtained when the feeding ratio of CD to PLA (wt%) was 20:1, stirring speed was 6 kr/min and the stirring time was 30 min. The structures and properties of the inclusion complexes were characterized by $^1H$ NMR, FTIR, DSC, FT-Raman, XRD and TGA. The DSC results demonstrated that the crystallization behavior of the inclusion complexes nearly disappeared. It was found that ${\beta}$-CD-PLA inclusion complex had a better thermal stability compared with the neat PLA. The model of the inclusion complexes was proposed on the basis of XRD, $^1H$ NMR and DSC results.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.5
• /
• pp.1201-1203
• /
• 2009

• Journal of Soil and Groundwater Environment
• /
• v.17 no.2
• /
• pp.47-53
• /
• 2012

In this study, the adsorption of $Cu^{2+}$ and $Cd^{2+}$ from aqueous solution on the biochar derived from used coffee grounds at different pyrolysis temperatures has been investigated as a potential low-cost treatment method for heavy metal-containing waters. Three biochar samples prepared by heating coffee sludge at temperature of $300^{\circ}C$ (B300), $500^{\circ}C$ (B500), and $700^{\circ}C$ (B700) were tested for the adsorption capacity and kinetics of Cd and Cu. Also the influencing factor of heavy metal removal by ion exchange in terms of cation exchange capacity (CEC) of each biochar was measured. Adsorption of Ca and Cu by biochar produced at higher pyrolysis temperature showed higher adsorption capacity but the optimal pyrolysis temperature based on performance and economy was known as $500^{\circ}C$. Sorption of Cu and Cd by biochar followed a Langmuir model at pH 6~6.5, attributing mainly to surface sorption. The biochar was more effective in Cu and Cd sorption than activated carbon (AC), with BC 500 being the most effective, which indicates that sorption of Cd and Cu by coffee sludge biochar is partly influenced by chemical sorption on surface functional group as well as physical sorption.

• The Korean Journal of Malacology
• /
• v.9 no.2
• /
• pp.85-93
• /
• 1993

Contamination of heavy metals in water and sediments along Mantyeong (river) has reached up to critical level, The object of the study is to dlucidate some macroinvertebrates which inhabit along the river in respect to the modulatory role in reducing the pollution. For the purpose, Scapharca subcrenata(sea shell) which is common in numbers and biomass in the area was collected, and cadmium (Cd) was subjected as a reference metal in the experiment. The seashell was dried and autoclaved, followed by pellet preparation under various concentration of Cd: 50,100,250,500 and 1,500 ug /pellet. Mice were fed for 3 months, althrough last group(5 mice), 1,500 ug/pellet, died within 4 weeksof the administration.MT-Cd in liver and kidney increased in correlation with the amont of Cd concentration in pellet, especially in kidney than in liver. Liver and kidney of the mice showed pathological changes such as cellular infiltration and focal necrosis in liver, and peri-tubular cell infiltration or tubular necrosis etc. The changes were more intensive by amount of the Cd. Overall results in the present study suggest that Cd may eventually combine with soluble-protein forming metalloprotein, then reduce the toxicity of heavy metal, How the formed Mt-Cd is discharged from the kidney and the mechanism shall be the further subject to be clarified.

• Korean Journal of Materials Research
• /
• v.8 no.5
• /
• pp.383-393
• /
• 1998

Cadmium telluride films were grown by close-spaced sublimation(CSS) technique. The effects of various deposition parameters such as ambient pressure, source- to-substrate spacings and temperatures on the growth rate and the microstructure were investigated. The growth mode of CdTe films showed a transition as the ambient pressure changed. This transition was interpreted in terms of the diffusion limited transport and the sublimation limited transport of Cd and $Te_2$ vapors. Experimental results indicated that the transition of growth mode was related with the mean free path of gas molecules. The growth rate and the microstructure of CdTe films were affected by the source type- bulk or powder. This change was due to the temperature difference at the source surface. XRD and SEM analysis showed that the growth rate was one of the main factors to determine CdTe microstructures.

• Journal of Korean Medicine Rehabilitation
• /
• v.18 no.2
• /
• pp.1-15
• /
• 2008

Objectives : The aim of this study was to know the immunity response of Haedongpibokhap-bang($H{\check{a}}it{\acute{o}}ngp{\acute{i}}f{\grave{u}}h{\acute{e}}-f{\bar{a}}ng$) to rheumatoid arthritis in collagen-induced arthritis(CIA) mice. Methods : For this purpose, Haedongpibokhap-bang($H{\check{a}}it{\acute{o}}ngp{\acute{i}}f{\grave{u}}h{\acute{e}}-f{\bar{a}}ng$) was orally administerd to mice with arthritis induced by collagen II and then value of immunocyte in spleen, draining lymph node and paw joint and cytokine(IL-6, $TNF-{\alpha}$), rheumatoid factor (IgG and IgM) in serum were measured. Results : 1. The arthritis index was significantly decreased. 2. In total cell counts of spleen, DLN and paw joint, the cells in spleen decreased while there was a significant increase in DLN and significant decrease in paw joint. 3. In lymph nodes, CD3+, CD3+/CD69+, CD4+, CD8+ cells increased significantly. 4. In joints, CD3+ and CD11+b/Gr-1+ cells decreased significantly. 5. Serum IL-6 and $TNF-{\alpha}$ were decreased significantly. 6. Production of serum IgG and IgM decreased significantly. Conclusions : The results present that Haedongpibokhap-bang($H{\check{a}}it{\acute{o}}ngp{\acute{i}}f{\grave{u}}h{\acute{e}}-f{\bar{a}}ng$) controls abnormal activity of immune system, inhibitig collagen-induced arthritis(CIA).

• Analytical Science and Technology
• /
• v.34 no.4
• /
• pp.143-152
• /
• 2021

Capillary electrophoresis (CE) is an effective technique to study chiral recognition because it offers flexibility in adjusting vital factors. Currently, various available cyclodextrins (CDs) can be employed for the chiral separation of numerous analytes. Herein, we investigate the enantioseparation behavior of lipoic acid enantiomers in various types of single and dual CD systems through CE. Additionally, several impacted CE parameters were optimized through the systematic investigation based on the design of experiment (DoE) concept for a single system comprising a heptakis (2,3,6-tri-O-methyl)-β-CD and a dual system containing the combination of the single CD with a sulfated-β-CD. Consequently, absolute enantioresolution was obtained within 15 min on a common standard bare fused-silica capillary (64.5/56 cm in total/effective length, 50/365 ㎛ inner/outer diameter), maintained at 15 ℃ and at an applied voltage of 24 kV. The optimal background electrolyte consisted of 6 mM heptakis (2,3,6-tri-O-methyl)-β-CD dissolved in the solution of 58 mM borate buffer at pH 10. Furthermore, the results of apparent binding constant experiments indicated that the S-enantiomer-heptakis (2,3,6-tri-O-methyl)-β-CD complex exhibited a stronger affinity than its R-enantiomer counterpart. The obtained electrophoretic mobility values could be utilized to interpret the resolution achieved at various CD concentrations and the mobility behavior of the complexes elucidated the migration order of the enantiomers in an electropherogram.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.4
• /
• pp.1021-1027
• /
• 2004

Panax ginseng has been used as a typical tonic medicine in Asian countries, such as Korea, China, and Japan. It has been reported that ginsenoside Rg1 in Panax ginseng increases the proportion of T helper cells in the whole T cells and promotes IL-2 gene expression in murine splenocytes. These studies imply that ginsenoside Rg1 increases the immune activity of CD4+ T cell, however the exact mechanism of ginsenoside Rg1 on helper T cell remains to be verified. The present study tried to elucidate the direct effect of Rg1 on helper T cell s activities and its Th1/Th2 lineage development. The results demonstrated that ginsenoside Rg1 had not mitogenic effects on the unstimulated CD4+ T cell, but augmented CD4+ T cell proliferation upon activating with anti-CD3/anti-CD28 antibodies in a dose dependent manner. Rg1 also enhanced the expression of cell surface protein CD69 on CD4+ T cell. In Th0 condition, ginsenoside Rg1 increases the expression of IL-2 mRNA, and enhances the expression of IL-4 mRNA on CD4+ T cells, suggesting Rg1 prefer to induce Th2 lineage development. In addition, ginsenoside Rg1 increases IL-4 secreting CD4+ T cell under Th2 skewed condition, while decreases IFN-γ secreting cell in Th1 polarizing condition. Thus, Rg1 enhances Th2 lineage development from naive CD4+ T cell both by increasing Th2 specific cytokine secretion and by repressing Th1 specific cytokine production. Therefore, these results suggest that ginsenoside Rg1 might be desirable agent for enhancing CD4+ T cell's activity, as well as the correction of Th1 dominant pathological disorders.

• Applied Chemistry for Engineering
• /
• v.10 no.8
• /
• pp.1192-1199
• /
• 1999

The morphology changes of cadmium hydroxide into ${\gamma}$ phase by eletrolytes were carried out to improve the high rate charge and discharge efficiency of pasted cadmium electrodes. KOH solutions with different concentrations of NaOH were used as eletrolytes. It was found that the utilization of active material of cadmium electrode was the best in an electrolyte with 1.82 M NaOH. The amount of ${\gamma}-Cd(OH)_2$ increased in proportion to the concentration of NaOH. The surface area measurement showed that an active material which contained mainly ${\gamma}-Cd(OH)_2$ had a higher specific surface area than an active material of ${\beta}-Cd(OH)_2$. In a sealed cell, the discharge capacity was improved at high rate charge and discharge (1.0 C, 2.0 C) by using an electrolyte with NaOH. Furthermore, these improved performances were maintained up to 500 cycles at 1.0 C rate charge and discharge cycles.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.3
• /
• pp.175-179
• /
• 2001

To find out the effect of cadmium(Cd) on growth of major vegetables in Korea, phytotoxicity and absorption of Cd were investigated with chinese cabbage, radish, and lettuce grown in upland soils of different Cd concentrations. Cadmium phytotoxicity was shown by growth retardation and leaf chlorosis in chinese cabbage and lettuce at the early growing stage. The threshold concentrations of growth damage resulting from the significant reduction (5%) of growth and yield of chinese cabbage and lettuce were $50{\sim}100$ and $10{\sim}25$ mg/kg soil, respectively. However, there was no significant reduction of radish yield under Cd treatment of 100 mg/kg soil. As Cd concentrations in soils increased, the contents of Cd in products were significantly increased, basically. The contents of Cd in edible part of chinese cabbage, radish, and lettuce grown at the 5 mg/kg Cd treated soils were 0.13, 0.18, and 3.37 mg/kg FW, respectively. Total absorbed Cd in the vegetables tended to occur in the following order, chinese cabbage > radish > lettuce above 25 mg/kg Cd treated soils whereas lettuce absorbed more Cd than chinese cabbage and radish below 10 mg/kg Cd concentration.