• Journal of Photoscience
• /
• v.1 no.1
• /
• pp.25-29
• /
• 1994

Diffuse reflectance and emission spectra of 7-hydroxyquinoline intercalated in the supercage of X and Y zeolites are compared with the absorption and emission spectra of aqueous 7-hydroxyquinoline solutions at various pH to understand protropic and photophysical properties of 7-hydroxyquinoline in zeolite microenvironments. Predominance of zwitterionic spedes with significant existences of the other three protropic equilibrium species, normal, protonated and deprotonated species in zeolite samples indicates that the major fraction of the molecules interact with strong acid and base sites of zeolite at an adsorbed position. Observed zeolite pHs of near neutrality are established by a near balance in numbers of many strong acid and base sites rather than by'small numbers or weakness of acid and base sites. Excitations of nonzwitterionic species such as deprotonated species also give prevailing zwitterionic fluorescence, indicating that excited and ground proton transfer cycles of protropic species can be triggered by photons in organized zeolite media as well as in water.

• Journal of Korea Soil Environment Society
• /
• v.3 no.3
• /
• pp.3-10
• /
• 1998

Acid/Base buffer capacity of soil is very important in prediction of contaminant transport for its direct impact on pH change of the system composed of soil-contaminant-water, In this research, diffuse double layer theory as well as two layer electrostatic adsorption model are applied to develop a theoretical model of buffer capacity of soil. Model application procedures are presented as well. Buffer capacity of Georgia kaolinite and Milwhite kaolinite was measured by acid-base titration. Model prediction and experimental results are compared.

• Neonatal Medicine
• /
• v.17 no.2
• /
• pp.155-160
• /
• 2010

Metabolic acidosis is commonly encountered issues in the management of critically ill neonates and especially of preterm infants during early neonatal days. In extremely premature infants, low glomerular filtration rate and immaturity of renal tubules to produce new bicarbonate causes renal bicarbonate loss. Higher intake of amino acids, relatively greater contribution of protein to the energy metabolism and mineralization process in growing bones are also responsible for higher acid load in premature infant than in adult. Despite widespread use of sodium bicarbonate in the management of severe metabolic acidosis, use of sodium bicarbonate in premature infants should be restricted to a reasonable but unproven exception such as ongoing renal loss. Despite concern about the low pH value (<7.2) which can compromise cellular metabolic function, no treatment guideline has been established regarding the management of metabolic acidosis in premature infants. Appropriately powered randomized controlled trials of base therapy to treat metabolic acidosis in critically ill newborn infants are demanding.

• Journal of Environmental Science International
• /
• v.17 no.8
• /
• pp.919-924
• /
• 2008

The surface properties and adsorption rates of activated carbon modified with acid and base were compared. The distribution ratio of C and C-H on the surface of activated carbon were decreased by modification with acid and base, but the distribution ratio of C-O, C=O, and O=C-O were increased. Base modification damaged the surface of activated carbon more than acid modification, it caused the effect of 6 percent increments of surface area. Adsorption rate model was more suitable to second order equation than first order equation. Adsorption rate was controlled by adsorption in pore better than in surface.

• Journal of Nutrition and Health
• /
• v.11 no.3
• /
• pp.13-20
• /
• 1978

Changes of free amino acids, nucleotides and their related compounds as taste compounds during sun drying of ascidian Cynthia roretzi, were analyzed by amino acid autoanalyzer and high speed liquid chromatography. In fresh ascidian, the results showed that 5'-UMP $(12.1\;{\mu}mole/g)$ was dominant and the content of cytosine, 2', 3'-CMP, 2', 3'-GMP, hypoxanhtine, 5'-AMP,5'-IMP were 5.8, 3.4, 3.1, 2,3, 1.7 and $1.3\;{\mu}mole/g$ ondry base respectively. 5'-IMP, 2', 3'-CMP and 2', 3'-GMP tended to degrade slowly and 5'-AMP, cytosine and 5'-UMP were decreased rapidly while hypoxanthine were increased remarkably during the sun drying. In dried ascidian, the content of hypoxanthine was the highest, 7.2 mole/g on dry base, whereas that of 5'-AMP $(0.5\;{\mu}mole/g)$) and 5'-IMP $(0.9\;{\mu}mole/g)$ were lower. Glutamic acid, alanine and serine were dominant amino acid in the fresh extracts, having 22.4% (611.3mg%, on dry qase), 19.8% (540.5mg%) and 14.8% (402.8mg%) of the total amino acid content respectively. The content of tyrosine, histidine, lysine, methionine, isoleucine and valine were low, and proline, phenylalanine were detected in trace amount. The free amino acid were not changed in composition but the increase of total free amino acid was approximately 116.8mg% during sun drying. In sun dried ascidian, glutamic acid (691.0mg, on dry base), alanine (641.3mg%), serine (469.5mg%), threonine (234.8mg%) and glycine (206.3mg%) were dominant amino acid. It is believed that glutamic acid, serine, alanine, threonine, glycine and hypoxanthine play an important role as taste compounds in sun dried ascidian.

• Mycobiology
• /
• v.38 no.4
• /
• pp.302-309
• /
• 2010

Formic acid is a representative carboxylic acid that inhibits bacterial cell growth, and thus it is generally considered to constitute an obstacle to the reuse of renewable biomass. In this study, Saccharomyces cerevisiae was used to elucidate changes in protein levels in response to formic acid. Fifty-seven differentially expressed proteins in response to formic acid toxicity in S. cerevisiae were identified by 1D-PAGE and nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) analyses. Among the 28 proteins increased in expression, four were involved in the MAP kinase signal transduction pathway and one in the oxidative stress-induced pathway. A dramatic increase was observed in the number of ion transporters related to maintenance of acid-base balance. Regarding the 29 proteins decreased in expression, they were found to participate in transcription during cell division. Heat shock protein 70, glutathione reductase, and cytochrome c oxidase were measured by LC-MS/MS analysis. Taken together, the inhibitory action of formic acid on S. cerevisiae cells might disrupt the acidbase balance across the cell membrane and generate oxidative stress, leading to repressed cell division and death. S. cerevisiae also induced expression of ion transporters, which may be required to maintain the acid-base balance when yeast cells are exposed to high concentrations of formic acid in growth medium.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.09a
• /
• pp.390-393
• /
• 2004

This study was carried out to evaluate the acid producing potential of geological materials such as pit wall, waste rock and stream sediments near the abandoned Imgi mine. The 17 samples used in this study were collected and then treated by static test such as Acid Base Accounting and etc. Samples of pit wall and waste rocks with high S content display a NAGpH values below 4.5 and net acid potential. Therefore some cost effective measures such as capping and groudwater flow barriers, will be required to reduce the impacts of ARD from the waste rock impoundment and the pit wall on near the stream.

• Archives of Pharmacal Research
• /
• v.23 no.2
• /
• pp.99-103
• /
• 2000

Acid and base catalyzed intramolecular cyclizations of N-benzoylthioureidoacetal, contain-ing four functional groups adjacent to thiourea such as benzocarbamoyl, acetal, thioure and amide, were investigated. The condensation reaction of N-benzoyl thiocarbamoylgly-cine amide in the presence of 10% aqueous NaOH provided 1-(2,2-dimethoxy)ethyl-imi- dazolidine-2-thione exclusively. In the presence of pyridine, it was transformed to 2- thiohydantoin. N-Benzoyl thiocarbamoyl glycine amide was completely transformed to an iminothiazolidine exclusively in the presence of Lewis acid such as borontrifluoride ether-ate or trimethylsilyl iodide. 1-(2,2-Dimethoxy)ethyl-imidazolidine-2-thione was transformed to imidazole[2,1-b]thiazole and pyrazino[5,1-a]imidazole in the presence of $BF_3$.$ET_2$O and formic acid, respectively.

• Journal of Korean Society of Forest Science
• /
• v.90 no.1
• /
• pp.133-138
• /
• 2001

Increased base cation loss and Al mobilization, a consequence of soil acid neutralization responses, are common in air polluted areas showing forest decline. The prediction models of acid neutralization responses were developed by using indicators of soil acidification level(pH, and base saturation) in order to assess the forest soil sensitivity to acidification. The soil acidification level was greatest in Namsan followed by Kanghwa, Ulsan, and Hongcheon, being contrary to regional total $ANC_H$ pattern through soil columns leached with additional acid ($16.7mmol_c\;H^+/kg$), Both base exchange and Al dissolution were main acid neutralization processes in all study regions. There were low base exchange and high Al dissolution in the regions of the low total $ANC_H$. The $ANC_M$ by sulfate adsorption was greatest in Hongcheon compared with other regions even though the AN rate was very low as 6.4%. Coefficients of adjusted determination of simple and multiple regression models between soil acidification level indicators and the acid neutralization responses were more than 0.52(p<0.04) and 0.89(p<0.01), respectively. The result suggests that soil pH and base saturation are available indicators for predicting the acid neutralization responses. These prediction models could be used as an useful method to measure forest soil sensitivity to acidification.

• Korean Journal of Microbiology
• /
• v.31 no.1
• /
• pp.44-47
• /
• 1993

A replication initiation gene was identified and its nucleotide sequence has been determined from a 3.8 kb, chloramphenicol acethyltransferase conferring R-plasmid pSBK203 of Staphylococcus aures. Location of the replication related region of pSBK 203 was determined by interuption with pUC 119 at XBaI and MspI sites which resulted in inactivation of replication in Bacilius subtilis. Base sequence of this region revealed on open reading frame of 942 base pairs, which encoded a 314 amino acid protein. Base sequence homology with other rep of pT181 family plasmids such as pT181, pC221, pC223, pS194, pU112, and pCW7 was ranged from 78% to 97% and the predicted amino acid sequence homology was from 72% to 95%.