• Bulletin of the Korean Chemical Society
• /
• 제28권4호
• /
• pp.520-528
• /
• 2007

A practical and efficient disposal of PCBs (polychlorinated biphenyls) in waste transformer oil by a chemical dechlorination process has been reported. The transformer oil containing commercial PCB mixtures (Aroclor 1242, 1254 and 1260) was treated by the required amounts of PEG 600 (polyethylene glycol 600), potassium hydroxide (KOH) and aluminum (Al), along with different reaction temperatures and times. The reaction of PEG with PCBs under basic condition produces arylpolyglycols, the products of nucleophilic aromatic substitution. The relative efficiencies of PCB treatment process were assessed in terms of destruction and removal efficiency (DRE, %). Under the experimental conditions of PEG600/KOH/Al/100 oC/2hr, average DRE of PCBs was approximately 78%, showing completely removal of PCBs containing 7-9 chlorines on two rings of biphenyl which appear later than PCB no. 183 (2,2',3,4,4',5',6-heptaCB) in retention time of GC/ECD. However, when increasing the reaction temperature and time to 150 oC and 240 min, average DRE of PCBs including the most toxic PCBs (PCB no. 77, 105, 118, 123 and 169) in PCB family reached 99.99% or better, with the exception of PCB no. 5 and 8 (2,3-diCB and 2,4'-diCB). In studying the reaction of PEG with PCBs, it confirmed that the process led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines. The process also permits complete recovery of treated transformer oil through simple segregating procedures.

• Applied Science and Convergence Technology
• /
• 제23권5호
• /
• pp.248-253
• /
• 2014

Air Gap Membrane Distillation (AGMD) is one of several technologies that can be used to solve problems fresh water availability. AGMD exhibits several advantages, including low conductive heat loss and higher thermal efficiency, due to the presence of an air gap between the membrane and condensation wall. A previous study by Bhardwaj found that the condensation surface properties (materials and contact angle) affected the total collected fresh water in the solar distillation process. However, the process condition differences between solar distillation and AGMD might result in different condensation phenomena. In contrast, N. Miljkovic showed that a hydrophobic surface has higher condensation heat transfer. Moreover, to the best of our knowledge, there is no study that investigates the effect of condensation surface properties in AGMD to overall process performance (i.e. flux and thermal efficiency). Thus, in this study, we treated the AGMD condensation surface to make it hydrophobic or hydrophilic. The condensation surface could be made hydrophilic by immersing and boiling plate in deionized (DI) water, which caused the formation of hydrophilic aluminum hydroxide (AlOOH) nanostructures. Afterwards, the treated plate was coated using hexamethyldisiloxane (HMDSO) through plasma-enhanced chemical vapor deposition (PECVD). The result indicated that condensation surface properties do not affect the permeate flux or thermal efficiency significantly. In general, the permeate flux and thermal efficiency for the treated plates were lower than those of the non-treated plate (pristine). However, at a 1 mm and 3 mm air gap, the treated plate outperformed the non-treated plate (pristine) in terms of permeate flux. Therefore, although surface wettability effect was not significant, it still provided a little influence.

• Journal of Physiology & Pathology in Korean Medicine
• /
• 제20권6호
• /
• pp.1593-1597
• /
• 2006

We hope to evaluate the effects of Gami-Choakwiyeum (GCKY) on the PPAR-${\gamma}$’ in the OVA induced asthma mouse model. Female BALB/c mice, 8 weeks of age and free of murine specific pathogens were used. Mice were sensitized by intraperitoneal injection of OVA emulsified in aluminum hydroxide in a total volume of 200 ${\mu}{\ell}$ on one day and 14 days. On 21, 22, and 23 days after the initial intraperitoneal injection of OVA, the mice were challenged using an ultrasonic nebulizer. GCKY was administered 7 times by oral gavage at 24 hour intervals fromdays 19 after intraperitoneal injection of OVA. Bronchoalveolar lavage was perfromed 72 hours after the last challenge, and total cell numbers in the BAL fluid were counted. Also, the level of PPAR-${\gamma}$ of normal and OVA-induced asthma moused with/without administration of GCKY were measured by Western blot analysis. For the histologic examination, the specimens were stained with hematoxylin 2 and eosin-Y.(H & E). Numbers of total cells were increased significantly at 72 h after OVA inhalation compared with numbers of total cells in the normal and the administration of GCKY. Especially, the increased numbers of eosinophils in BAL fluids after OVA inhalation were significantly increased. However, the numbers of eosinophils reduced by the administration of GCKY. Western blot analysis revealed that PPAR-${\gamma}$ levels in nuclear level were increased slightly after OVA inhalation compared with the levels in the normal group. After the administration of GCKY, PPAR-${\gamma}$ levels in cytosolic and nuclear levels at 72 h after OVA inhalation were markedly increased. On pathologic examination, there were many acute inflammatory cells around the alveoli, bronchioles, and airway lumen of mice with OVA-induced asthma compared with inflammatory cells in the normal group. However, acute inflammatory cells around alveoli, bronchioles, and airway lumen markedly decreased after administration of GCKY, GCKY can increase a PPAR-${\gamma}$ level and could be an effective treatment in asthma patients through the PPAR-${\gamma}$ mechanism for bronchial asthma.

• Journal of Ginseng Research
• /
• 제39권1호
• /
• pp.38-45
• /
• 2015

Background: Korean ginseng is a well-known medicinal herb that has been widely used in traditional medicine to treat various diseases, including asthma. Ginseng can be classified as white ginseng (WG) or red ginseng (RG), according to processing conditions. In this study, the authors compared the efficacies of these two ginseng types in a mouse model of acute asthma. Methods: To produce the acute asthma model, BALB/c mice were sensitized with ovalbumin (OVA) and aluminum hydroxide, and then challenged with OVA. WG and RG extracts were administered to mice orally. The influences of WG and RG on airway hyperresponsiveness (AHR), immune cell distributions in bronchoalveolar lavage fluid (BALF), and OVA-specific immunoglobulin E (IgE), IgG1, and IgG2a in serum were investigated. Cytokine production by lymphocytes isolated from peribronchial lymph nodes and histopathological changes was also examined. Results: In OVA-sensitized mice, both WG and RG reduced AHR and suppressed immune cell infiltration in bronchoalveolar regions. BALF OVA-specific IgE levels were significantly lower in RG-treated OVAsensitized mice than in the OVA-sensitized control group. WG and RG also suppressed inflammatory cytokine production by peribronchial lymphocytes. Histopathological findings showed reduced inflammatory cell infiltration and airway remodeling (e.g., epithelial hyperplasia) in WG- and RG-treated OVA mice compared with OVA controls. Conclusion: In this study, WG and RG showed antiasthmatic effects in an OVA-sensitized mouse model, and the efficacies of RG were found to be better than those of WG.

• The Korea Journal of Herbology
• /
• 제24권2호
• /
• pp.39-48
• /
• 2009

Objectives : To clarify the possible effect of JS (Juglans sinensis), PCF (Psoralea corylifolia L.), and J+P(JS+PCF), we examined their influence on the development of pulmonary eosinophilic inflammation in the asthmatic murine model. Methods : All mice were immunized on two different days (21 days and 7 days before inhalational exposure) by intraperitonial injections of 0.2 ml alum-precipitated Ag containing 100 ${\mu}$g of OVA bound to 4 mg of aluminum hydroxide in PBS. Seven days after the second sensitization, mice were exposed to aerosolized ovalbumin for 30 minutes/day on 3 days/week for 8 weeks (at a flow rate of 250 L/min, 2.5% ovalbumin in normal saline) and, JS, PCF and J+P (200 mg/kg, 400 mg/kg) were orally administered 3 times per week for 8 weeks. Results : The suppressive effects of JS, PCF, and J+P were demonstrated by the accumulation of eosinophils into airways, with the reduction of eosinophils and lung leukocytes. These were correlated with the marked reduction of IL-4, IL-5, IL-13 levels in the BALF and serum. OVA-specific IgE levels were also decreased in serum and BAL from these mice. And also JS, PCF, and J+P decreased eosinophilic CCR3 and CD11b expression in lung tissue. Conclusions : These results indicate that JS, PCF, and J+P have deep inhibitory effects on airway inflammation and hyper-responsiveness in the asthmatic murine model. The suppression of IL-5, IgE, and eosinophilils and the increase of IFN-${\gamma}$ production in BALF seem to contribute to these effects. Specially, esosinophils and TNF-a in J+P combination group were significantly reduced in BALF and lung tissue. Hence, the results indicated that JS, PCF, and J+P could act as an immuno-modulator which possesses anti-inflammatory and anti-asthmatic property by modulating the imbalance between Th1 and Th2 cytokines.

• The Korea Journal of Herbology
• /
• 제24권1호
• /
• pp.73-78
• /
• 2009

Objectives : In this study, we studied the effect of Pinellia Ternata (PT) on regulatory T cells and CD3+CCR3+ Th2 cells number in asthma model mice. Methods : All mice were immunized on two different days (21 days and 7 days before inhalational exposure) by i.p. injections of 0.2 $m\ell$ alum-precipitated Ag containing 100 ${\mu}g$ of OVA bound to 4 mg of aluminum hydroxide in PBS. Seven days after the second sensitization, mice were exposed to aerosolized ovalbumin for 30 min/day on 3 days/week for 12 weeks(at a flow rate of 250 L/min, 2.5％ ovalbumin in normal saline) and PT (400, 200 mg/kg) were orally administered 3 times a week for 8 weeks. After C57BL/6 mice were orally given of PT, the percentages, cell numbers, phenotype and function of CD4+CD25+Treg cells were determined by flow cytometry. Results : The cell numbers of CD4+CD25+Treg cell subsets were markedly increased in PT treated mice as reported. However, PT significantly reduced the CD3+CCR3+ Th2 cells in PBMC and lung of mice. Conclusions : These results indicate that PT has a deep inhibitory effect on asthma model mice by increase the number of regulatory T cells, and by reducing CD3+CCR3+ Th2 cells.

• The Korea Journal of Herbology
• /
• 제24권1호
• /
• pp.79-88
• /
• 2009

Objectives : It has been recently shown that Piperis Longi Fructus (PLF) is involved in the reduction of eosinophil recruitment and production of Th2 cytokines in vivo. However, the main therapeutic mechanisms of PLF remains a matter of considerable debate. To investigate the therapeutic mechanisms of PLF, we examined the influence of PLF on regulatory T cells number, IgE, histamine production in vivo and Th1/Th2 cytokine balance in vitro. Methods : All mice were immunized on two different days (21 days and 7 days before inhalational exposure) by i.p. injections of 0.2 $m\ell$ alum-precipitated Ag containing 100 ${\mu}g$ of OVA bound to 4 mg of aluminum hydroxide in PBS. Seven days after the second sensitization, mice were exposed to aerosolized ovalbumin for 30 min/day on 3 days/week for 12 weeks(at a flow rate of 250 L/min, 2.5％ ovalbumin in normal saline) and PLF (150 mg/kg) were orally administered 3 times a week for 8 weeks. Splenocytes from C57BL/6 mice at 8 weeks of age were stimulated with anti-CD3 (1 mg/ml) plus anti-CD28 (1 mg/ml) antibody for 48hrs. IL-4 and IFN-$\gamma$ in the culture supernatants were measured by ELISA Results : The suppressive effects of PLF on asthma model were demonstrated by the increase the number of regulatory T cells and by reducing IgE, histamine production in vivo and modulation of Th1/Th2 cytokine balance. Conclusions : These results indicate that PLF has a deep inhibitory effects on asthma model mice by increase the number of regulatory T cells, and by reducing IgE, histamine production.

• Journal of Korean Society of Forest Science
• /
• 제109권2호
• /
• pp.157-168
• /
• 2020

The sensitivity of forest soil to acidification in the Republic of Korea (ROK) was evaluated based on pH_H2O, cation exchange capacity (CEC), and base saturation (BS). Sensitivity to acidification was categorized into three grades: adequate level (AL, pH ≧ 4.2, CEC ≧ 15cmol/kg, BS ≧ 15%), caution level (CL, at least one indicator is below AL), and severe Level (SL, all three indicators are below AL). Soil samples were collected from the 65 stationary monitoring plots (40 × 40 ㎢), distributed throughout ROK. Only 19% of soil samples were classified as AL, while 66% and 15% were CL and SL, respectively. The median of pH_H2O, CEC, BS, and Ca/Al indicator in AL soils was pH 4.64, 20.7cmol/kg, 29%, and 6.3, respectively. Moreover, BC_ex (K⁺, Mg²⁺, Ca²⁺) and available phosphorus (AP) concentration compared with a threshold value and molar ratio of BC_ex and AP to total nitrogen (TN) was high. This indicates that AL soils have a good nutrient condition. The molar Ca/Al ratio, an indicator for toxicity of exchangeable aluminum (Al_ex), was more than 1, indicating no negative impact of Al_ex on plant growth. On the contrary, the median of pH_H2O, CEC, and BS in SL soils was pH 4.02, 13.2cmol/kg, and 10%, respectively. The Ca/Al index was less than 0.6, which indicates that negative impacts of Al_ex on plants were high. Furthermore, both the concentration of BC_ex in SL soils and the BC_ex/TN ratio were the lowest among the three acidity degrees. This shows that SLsoils can be degraded by soil acidification compared with less acidic soils.

• Restorative Dentistry and Endodontics
• /
• 제32권5호
• /
• pp.419-425
• /
• 2007

The aim of this study was to evaluate the radiopacity and cytotoxicity of three resin-based (AH 26, EZ fill and AD Seal), a zinc oxide-eugenol-based (ZOB Seal), and a calcium hydroxide-based (Sealapex) root canal sealers. Specimens, 10 mm in diameter and 1 mm in thickness, were radiographed simultaneously with an aluminum step wedge using occlusal films, according to ISO 6876/2001 standards. Radiographs were digitized, and the radiopacity of sealers was compared to the different thicknesses of the aluminum step wedge, using the Scion image software. Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of each material was determined in immortalized human periodontal ligament (IPDL) cells. The results demonstrated that EZ fill was the most radiopaque sealer, while Sealapex was the least radiopaque (p < 0.05). AH 26, AD Seal and ZOB Seal presented intermediate radiopacity values. All the materials evaluated, except for Sealapex, presented the minimum radiopacity required by ISO standards. The cell viabilities of resin-based root canal sealers were statistically higher than that of other type of root canal sealers through the all experimental time. Further, EZ fill showed statistically lower cell viability in 24 and 48 hours compared to AD Seal and in 72 hours compared to all other resin-based root canal sealers. However, there was no correlation between the radiopacity and cytotoxicity of three resin-based root canals sealers (p > 0.05). These results indicate that resin-based root canal sealer is more biocompatible and has advantage in terms of radiopacity.

• Journal of the Korean Chemical Society
• /
• 제39권8호
• /
• pp.627-634
• /
• 1995

Layered double hydroxides ($Mg-Al-CO_3$ systems, LDH), which are hydrotalcite-like anionic clay minerals, having different $Mg^{2+}\;to\;Al^{3+}$ ratio were synthesized by coprecipitation method. The subsequent products were characterized by the following methods; elemental analysis, X-ray powder diffraction, thermal analysis (DSC and TGA), FT-IR and $^{27}$Al-MAS NMR. X-ray powder patterns showed that the products formed were layered structure materials. Two heat absorption peaks were observed around 20 ∼280$^{\circ}C$ (surface water and interlayer water) and 280∼500$^{\circ}C$ (water from lattice hydroxide and carbon dioxide from interlayer carbonate) in DSC diagrams, and they were quantitatively analyzed by TGA diagrams (in case LDH4 16.2% and 28.6% respectively). FT-IR spectra indicate that the interlayer carbonate ions occupied symmetrical sites between two adjacent layers in a parallel direction. $^{27}$Al-MAS NMR spectra show only single resonance (8.6 ppm) of the octahedrally coordinated aluminum similar magnesium. When LDH4 was calcined at 560$^{\circ}C$ for 3 hours in air, its layered structure was destroyed giving a mixed metal oxide. However it readily became rehydrated in aqueous chromate solution to its original structure.