• Carbon letters
• /
• v.8 no.4
• /
• pp.321-325
• /
• 2007

The oxygen and nitrogen enriched activated carbons were obtained from modification of commercial activated carbon by using nitric acid, sodium hydroxide and urea. Zeta-potentials of modified activated carbons were investigated in relation to copper ion adsorption. The structural properties of modified activated carbons were not so much changed, but the zeta-potentials and isoelectric points were considerably changed. The zeta-potential of nitric acid modified activated carbon was the most negative than other activated carbons in the entire pH region, and the $pH_{IEP}$ was shifted from pH 4.8 to 2.6, resulted in the largest copper ion adsorption capacities compare with other activated carbons in the range of pH 3~6.5. In case of urea modified activated carbon, copper ion adsorption was larger than that of the as-received activated carbon from pH 2 to pH 6.5 even though the $pH_{IEP}$ was shifted to pH 6.0, it was due to the coordination process operated between nitrogen functional groups and copper ion. The adsorption capacity of copper ion was much influenced by zeta-potential and $pH_{IEP}$ of carbon adsorbent.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.376-376
• /
• 2016

Poly(ethylene oxide) (PEO)/functionalized bacterial cellulose nanowhiskers (f-BCNW) (0.1 wt%) composite nanofibers were fabricated by electrospinning process and the thermomechanical properties were significantly enhanced more than the PEO and PEO/bacterial cellulose nanowhiskers (BCNW) (0.1 wt%) composite nanofibers. The functionalization of BCNW (f-BCNW) was performed by microwave plasma treatment for effects of nitrogen functionalization of chemically-driven BCNW. The N-containing functional groups of f-BCNW enhanced chemical bonding between the hydroxyl groups of the polymer chains in the PEO matrix and diameter size of PEO/f-BCNW (0.1 wt%) composite nanofibers were decreased more than PEO and PEO/BCNW (0.1 wt%) composite nanofibers on the same concentration. The strong interfacial interactions between the f-BCNW nanofillers and polymer matrix were improved the thermomechanical properties such as crystallization temperature, weight loss and glass transition temperature (Tg) compared to PEO and PEO/BCNW composites nanofibers. The results demonstrated that N2 plasma treatment of BCNW is very useful in improving thermal stability for bio-applications.

• Journal of Nutrition and Health
• /
• v.31 no.3
• /
• pp.243-252
• /
• 1998

This study was conducted to investigated the short-term effects of early weaning and protein intake on organ and cell growth, nitrogen metabolism and physiological functions of rats. Five groups of early weaned rats separated from the dam on the 15th day postpartum were each given one five diets consisting of either one of the three levels of casein-low(8%), -normal (16%), and -high(32%), or a normal level (16%) of isolated soy protein(ISP) or egg yolk protein, for 7 days. The normal weaned rats were fed maternal breast milk for three weeks from birth. On the 22nd day postpartum , all the rats were sacrificed . The weight gain of the early weaned rats, especially the ones fed high protein, was observed to be significantly lower than that of the normal weaned rats. By the 15th day, of early weaning and especially in the ISP-fed rats, the total DNA contents of liver and kidney, which may be said to represent an index of cell numbers, significantly decreased, but their fresh and dry weight and protein/DNA ratio, allegedly representing an index of cell size, significantly increased , not affecting the cell number and cell size of brain. There were no differences in total serum protein and albumin concentrations between early and normal weaned rats. In the early weaned rats observed , the serum urea N and $\alpha$-amino N concentrations significantly increased in high protein-fed rats, and decreased in low protein-fed rats. Another observation was that no significant difference was noticed as regards to serum GOT activity, total bilirubin, uric acid, and creatinine concentration, which may represent indices of liver and kidney functions, among rat groups, GPT activity was an exception . These results suggest that premature weaning and the quality and quantity of dietary protein significantly affect organ and cell growth and nitrogen metabolism but does not seriously affect physiological functions in the neonatal development of rats.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.2
• /
• pp.383-393
• /
• 2019

The purpose of this study was to investigate the improvement effect of turmeric (Curcuma longa L.) on the hepatic functional enzyme and catalase activity of streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley (SD) male rats were divided into four groups (n=6), and fed experimental diets containing turmeric meal [basal diet+5% turmeric (BT), basal diet+STZ+5% turmeric (ST)], and control (basal diet, BD), BS groups (basal diet+STZ). Serum concentrations of creatinine and blood urea nitrogen (BUN) were significantly decreased (p<0.05) by 5% turmeric supplementation diet. The activities of akaline phosphatase (ALP), lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT), amylase and lipase were decreased in the BD, BT and ST group than BS group. The catalase (CAT) activity was significantly increased (p<0.05) in turmeric supplementation diet (BT, ST group) than diabetic group (BS). Furthermore, the activities of amylase and lipase in the sera of turmeric diet group were significantly decreased (p<0.05). In vivo experiments with diabetic rats showed that ingestion of turmeric supplementation diet were effective in creatinine concentration, and hepatic functional enzyme activities.

• Journal of the East Asian Society of Dietary Life
• /
• v.23 no.1
• /
• pp.44-52
• /
• 2013

This study investigated hepatic functional improvement and anti-fibrotic effects of water extracts of black tea. Male Sprague-Dawley rats were divided into four groups (normal, control, and two experimental subgroups: Ba, Bb) and observed for 3 weeks. Liver fibrosis in rats developed from carbon tetrachloride ($CCl_4$) administration, except for the normal group. Except for the normal and control group, the two experimental subgroups were fed water extracts of black tea. The food efficiency ratio significantly increased in the experimental group compared to the control group. The experimental group had a significantly lower liver weight compared to the control group. The ratio of liver weight to body weight was significantly lower in the experimental group than the control group. The levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, blood urea nitrogen, and low-density lipoprotein-cholesterol in serum significantly decreased in the experimental group compared to the control group. The values of hydroxyproline and malondialdehyde in liver were even lower in the experimental group than the control group. In observations on liver histology, weaker inflammation and fibrosis were observed in the experimental group compared to the control group. In conclusion, water extracts of black tea help hepatic cells keep their functions, restraining and protecting the liver from impairments caused by $CCl_4$ administration, and can be effective as anti-fibrotic agents.

• Journal of the Korean Electrochemical Society
• /
• v.16 no.2
• /
• pp.65-69
• /
• 2013

In order to improve capacitance of activated carbon for electric double layer capacitors, peptide bond was induced on the surface of the activated carbon by urea. Urea induced activated carbon has been stabilized through carbonization. Electrochemical characteristics was observed by cyclic voltammetry for specific capacitance, electrochemical impedance spectroscope for measuring resistance and charge-discharge for testing the cyclic ability. In the result, specific capacitance is increased about 22.9% than the activated carbon. And it shows excellent cycle performance and decreasing resistance with the introduction of nitrogen functional groups.

• Korean Chemical Engineering Research
• /
• v.46 no.2
• /
• pp.436-442
• /
• 2008

Organic-inorganic hybrid mesoporous anion-exchange resins were prepared for the adsorption of anions from aqueous solutions. The prepared samples were characterized using nitrogen adsorption-desorption measurements, Fourier transform infrared (FTIR) spectroscopy, and elemental analyses. Batch and kinetic experiments were performed to examine the anion-exchange performances of the prepared samples. Among the prepared samples, the hybrid mesoporous anion-exchange resins functionalized with tributylammonium groups showed higher adsorption capacities for perrhenate ions than did the resin functionalized with trimethylammonium groups. The surfactant, hexadecylamine, which had hydrophobic alkyl chains, also showed affinity for hydrophobic perrhenate anions.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.26 no.4
• /
• pp.239-248
• /
• 2006

This study was conducted not only to investigate effects of different supplementation levels of Acanthopanax senticosus leaves on feed intakes, nutrient digestibility, nitrogen retention, and blood metabolites in Korean black goats but also to obtain basic data for nutritive value of Acanthopanax senticosus leaves and production of high quality functional animal products. Twelve Korean black goats were allotted to treatments in four groups of three goats per treatment and then they were housed in individual metabolism cages with completely random arrangements for 21 days. Four treatments were separated into controls and three different supplementation levels of Acanthopanax senticosus such as 10, 20 and 30%, respectively. For the chemical composition of experimental diets, crude protein (CP) contents of controls were 13.39% and those of supplementation treatments were lowered with increasing levels of Acanthopanax senticosus. Control groups tended to have higher acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents as compared to supplementation groups, but non-fibrous carbohydrate (NFC) contents tended to be higher far supplementation groups than those for controls. Feed intakes had no significant difference among treatments, but digestible dry matter amounts were significantly higher for 20 and 30% supplementation groups than those for other treatments. Dry matter intakes per metabolic body weight and their ratio per body weight were highest in 20% group, but those of 40% groups were lowest (p<0.05). Crude protein, ADF and NDF digestibilities were significantly higher in Acanthopanax senticosus supplementation groups in comparison to controls (p<0.05), and in particular, they were increased with increasing supplementation levels of tranthopanax senticosus. Nitrogen retention was significantly higher for 20 and 30% treatments than those fur controls (p<0.05). Plasma urea nitrogen concentration was significantly lower for 30% supplementation group than those fur controls (p<0.05). Furthermore, plasma triglyceride concentration was significantly lower for Acanthopanax senticosus groups than those for controls (p<0.05). The results showed that supplemental level of 20% Acanthopnnax senticosus leaves to Korean black goats improved nutrient digestibility, nitrogen retention, and plasma urea nitrogen and triglyceride concentrations. Consequently, it might contribute to more efficient production of Korean black goats.

• Journal of Veterinary Science
• /
• v.24 no.2
• /
• pp.27.1-27.15
• /
• 2023

Background: The relationships between the postpartum subacute ruminal acidosis (SARA) occurrence and predicted bacterial functions during the periparturient period are still not clear in Holstein cows. Objectives: The present study was performed to investigate the alterations of rumen fermentation, bacterial community structure, and predicted bacterial functional pathways in Holstein cows. Methods: Holstein cows were divided into the SARA (n = 6) or non-SARA (n = 4) groups, depending on whether they developed SARA during the first 2 weeks after parturition. Reticulo-ruminal pH was measured continuously during the study period. Reticulo-ruminal fluid samples were collected 3 weeks prepartum, and 2 and 6 weeks postpartum, and blood samples were collected 3 weeks before, 0, 2, 4 and 6 weeks postpartum. Results: The postpartum decline in 7-day mean reticulo-ruminal pH was more severe and longer-lasting in the SARA group compared with the non-SARA group. Changes in predicted functional pathways were identified in the SARA group. A significant upregulation of pathway "PWY-6383" associated with Mycobacteriaceae species was identified at 3 weeks after parturition in the SARA group. Significantly identified pathways involved in denitrification (DENITRIFICATION-PWY and PWY-7084), detoxification of reactive oxygen and nitrogen species (PWY1G-0), and starch degradation (PWY-622) in the SARA group were downregulated. Conclusions: The postpartum SARA occurrence is likely related to the predicted functions of rumen bacterial community rather than the alterations of rumen fermentation or fluid bacterial community structure. Therefore, our result suggests the underlying mechanisms, namely functional adaptation of bacterial community, causing postpartum SARA in Holstein cows during the periparturient period.

• Journal of Korean Society for Atmospheric Environment
• /
• v.32 no.2
• /
• pp.176-183
• /
• 2016

Activated carbon fibers (ACFs) for $CO_2$ adsorption were prepared from polyacrylonitrile (PAN) fiber through the systematic processes such as oxidation, activation and amination with the focus on the formation of nitration functional groups. Textural analysis of test samples revealed the decrease of specific surface area and pore volume by chemical activation including amination. The ratio of micropores to the total volume was 0.85 to 0.91, which was high enough with the pore size of 1.57 to 1.77 nm. Nitrogen compounds such as imine, pyridine and pyrrole presenting favorable interforces to $CO_2$ molecules were formed throughout the whole preparation steps. The aminated ACF adsorbent showed the enhanced adsorption capacity, 0.40 mmol/g for low-level $CO_2$ flow (3000 ppm) at room temperature. Selectivity of $CO_2$ against dry air ($O_2$ & $N_2$) also increased from 1.00 to 4.66 by amination.