• Investigative Magnetic Resonance Imaging
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• v.18 no.1
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• pp.52-58
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• 2014

Purpose : To establish a pH measurement system for a mouse tumor study using a clinical scanner, to develop the $^1H$ and 31P radio frequency (RF) coil system and to test pH accuracy with phantoms. Materials and Methods: The $^1H$ and the $^{31}P$ surface coils were designed to acquire signals from mouse tumors. Two coils were positioned orthogonally for geometric decoupling. The pH values of various pH phantoms were calculated using the $^1H$ decoupled $^{31}P$ MR spectrum with the Henderson-Hasselbalch equation. The calculated pH value was compared to that of a pH meter. Results: The mutual coil coupling was shown in a standard $S_{12}$. Coil coupling ($S_{12}$) were -73.0 and -62.3 dB respectively. The signal-to-noise ratio (SNR) obtained from the homogeneous phantom $^1H$ image was greater than 300. The high resolution in vivo mice images were acquired using a $^{31}P$-decoupled $^1H$ coil. The pH values calculated from the $^1H$-decoupled $^{31}P$ spectrum correlated well with the values measured by pH meter ($R^2$=0.97). Conclusion: Accurate pH values can be acquired using a $^1H$-decoupled $^{31}P$ RF coil with a clinical scanner. This two-surface coil system could be applied to other nuclear MRS or MRI.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1381-1388
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• 2012

An in vitro experiment was conducted to examine the effects of defaunation (removal of protozoa) on ruminal fermentation characteristics, $CH_4$ production and degradation by rumen microbes when incubated with cereal grains (corn, wheat and rye). Sodium lauryl sulfate as a defaunation reagent was added into the culture solution at a concentration of 0.000375 g/ml, and incubated anaerobically for up to 12 h at $39^{\circ}C$. Following defaunation, live protozoa in the culture solution were rarely observed by microscopic examination. A difference in pH was found among grains regardless of defaunation at all incubation times (p<0.01 to 0.001). Defaunation significantly decreased pH at 12 h (p<0.05) when rumen fluid was incubated with grains. Ammonia-N concentration was increased by defaunation for all grains at 6 h (p<0.05) and 12 h (p<0.05) incubation times. Total VFA concentration was increased by defaunation at 6 h (p<0.05) and 12 h (p<0.01) for all grains. Meanwhile, defaunation decreased acetate and butyrate proportions at 6 h (p<0.05, p<0.01) and 12 h (p<0.01, p<0.001), but increased the propionate proportion at 3 h, 6 h and 12 h incubation (p<0.01 to 0.001) for all grains. Defaunation increased in vitro effective degradability of DM (p<0.05). Production of total gas and $CO_2$ was decreased by defaunation for all grains at 1 h (p<0.05, p<0.05) and then increased at 6 h (p<0.05, p<0.05) and 12 h (p<0.05, p<0.05). $CH_4$ production was higher from faunation than from defaunation at all incubation times (p<0.05).

• Polymer(Korea)
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• v.33 no.5
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• pp.441-445
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• 2009

In order to develop an intelligent delivery system for cosmetic active agents (e.g., arbutin, ascorbic acid, and adenosine), pH-responsive P(MAA-co-PEGMA) hydrogel particles having an average size of approx. $2{\mu}m$ and spherical shape were synthesized via dispersion photopolymerization. There was a drastic change in the swelling ratio of P (MAA-co-PEGMA) hydro gels at a pH 5, which is the $pK_a$ of the hydrogel. To determine the factors that have an effect on the loading of cosmetic active agents into the hydrogel, the loading efficiency of the active agents was investigated at various MAA and EG compositions of the hydrogel and the loading pH conditions. When the MAA contents in the hydrogel decreased, the loading efficiency of the active agents increased. In loading experiments with different pH conditions, the active agents showed higher loading efficiency into the hydrogel at the pH where the hydrogel was at the swollen state than at the pH where the electrostatic repulsion was minimized.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.851-856
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• 2005

The aim of this experiment was to evaluate the stability of anti-Helicobacter pylori IgY in water soluble fraction(WSF) of egg yolk according to the heat, pH and digestive enzyme treatment. Anti-H. pylori IgY content of WSF remained 76% after pasteurization(63$^{\circ}C$ for 30 min). The stability of anti-H. pylori IgY at different pH showed a tendency to diminish according to decreasing pH from 7.0 to 1.5(p＜0.05). Anti-H. pylori IgY content was 84.4% after treatment for 1 hour at 37$^{\circ}C$ in pH 5.0. There were significantly differences in IgY content between 1 hour and 2 hours at pH 2.0 in 200 units of pepsin treatment(p＜0.05). However, IgY was relatively stable at pH 4.0 regardless of the reaction time and the concentration of pepsin. The stability of IgY of egg yolk after the treatment of trypsin was significantly higher than that of water soluble fraction (p＜0.05). This results indicated that anti-H. pylori IgY showed relatively a good stability on heat, pH and digestive enzyme.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.30-35
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• 1999

The purpose of this study was to evaluate the effect of temporary pH reductions on tuberization of ‘Dejima’potato in aeroponics. The pH and EC of nutrient solution were adjusted to 6.0∼6.5 and 1.2mS/cm, respectively. On 35th day after planting, plants were subjected to pH 3.0, 4.0, 5.0 and 6.5 for 10hrs. After 5 days mini-tuberization was shown in pH 3.0 treatment and was significantly increased up to 20 days. Temporary low pH treatment resulted in the increase of stolen formation and of tuber dry weight. Number of mini-tubers per plant on 90th-day after planting was 72.1, 69.8, 65.2, and 60.3 in pH 3.0, 4.0, 5.0 and 6.5 respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.3
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• pp.237-243
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• 1992

To determine effects of simulated acid rain on the growth and yield of rice, soybean and sesame, and on the soil acidity, two cultivars of rice, soybean and sesame were exposed twice a week to one of four simulated rain acidities[pH 2. 6, 3. 6, 4. 6 and 5. 6(control)]. The plants were protected from ambient rain by a polyethylene film cover. No visible damage due to the simulated acid rain was observed at any stage of growth for either of the crops. In rice, heading date, plant height and yield components except ripening ratio were not significantly affected by the pH ofsimulated rain, but the ripening ratio and rough rice yield linearly decreased as the pH of simulated rain was decreased. In soybean, maturing date and yield components except 100 seed weight were not significantly influenced by the pH of simulated rain, but the 100 seed weight and yield linearly decreased as the pH of simulated rain was decreased. Seed yield and the other agronomic characteristics of sesame were not significantly affected by the pH of simulated rain. Soil pH after cropping rice, soybean and sesame decreased as pH of simulated rain was decreased.

• Korean journal of food and cookery science
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• v.6 no.3 s.12
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• pp.9-15
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• 1990

Peanut prptein isolate was tested for the purpose of finding out the effect of pH, Sodium Chloride concentration and heat treatment on the solubility, surface hydrophobicity, foam expansion and foam stability. The solubility of peanut protein isolate was affected by pH and showed the lowest value at pH 4.5. When the peanut protein isolate was heated, the solubility decreased at pH 3 and pH 7 but at pH 9 solubility increased. At all pH range, solubility decreased as NaCl was added. The surface hydrophobicity of peanut protein isolate showed the highest value at pH 1.5. Generally, at acidic pH range the surface hydrophobicity was high, but at alkaline region, the surface hydrophobicity increased as the temperature increased. And when NaCl was added, the surface hydrophobicity was also increased. Foam expansion of peanut protein isolate was no significant difference among the values about pH. When the peanut protein was heated and NaCl was added, foam expansion was increased at pH 7. Foam stability was significantly low at pH 4.5 and foam stability was increased at acidic pH region below pH 4.5. At pH 7 and pH 9, heat treatment above $60^{\circ}C$ increased foam stability. When NaCl was added, foam stability was significantly increased at pH 3 and pH 7.

• Korean Journal of Food Science and Technology
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• v.23 no.3
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• pp.355-359
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• 1991

Effects of temperature and pH on thermal degradation of monosodium glutamate(MSG) were investigated during heating of 2% MSG solution at $100{\sim}200^{\circ}C\;and\;pH\;4{\sim}9$. The results showed that the degradation of MSG was very significantly affected by heating temperature and pH. Three hours of heating at $pH\;4\;and\;120^{\circ}C$ resulted appr. 73% MSG degradation while 3 hours at $100^{\circ}C$ decreased only 12%. The comparison study of initial rate of MSG degradation and degradation rate constants showed the highest degradation rate and rate constant and low values in the range of $pH\;6{\sim}8{\sim}$. The values of activation energy calculated from linear relationship of rate constants and 1/T were 18.3 and 9.2 kcal/mole for pH 4 and 5, respectively.

• Polymer(Korea)
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• v.35 no.6
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• pp.520-525
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• 2011

Superporous hydrogels (SPHs) with fast swelling and superabsorbent properties are useful materials in various biomedical fields, by improving the swelling properties of conventional hydrogels based on their unique porous structure. In this study, Eudragit polymers were used as coating materials to control the swelling properties of poly(acrylic acid-co-acrylamide) based SPHs by environmental pH. The SPHs were coated with Eudragit L100 and S100 that have different pH characteristics as enteric coating materials by a dip coating method, and their pH dependent swelling behaviors were observed in various pH environments. The swelling of SPHs was inhibited at a low pH range, but significantly enhanced above a characteristic pH of Eudragit polymers. This pH dependent swelling behavior of hydrogels could be modulated by the characteristics of the enteric coating polymers.

• Journal of Korean Society on Water Environment
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• v.39 no.6
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• pp.433-438
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• 2023

This study investigated the growth and metabolic characteristics of Arthrospira platensis (A. platensis) according to pH, which has an alkaline optimal pH. The intake of inorganic carbon was expected to be the highest at the optimum pH 9, but it was different from the expectation, so the cause of the excessive intake of inorganic carbon at pH 7 was investigated. We tried to verify the triacylglycerol (TAG) synthesis metabolic mechanism because it was assumedthat the inorganic carbon intake of A. platensis according to pH is closely related to lipid production inside the cell. To verify this, the effects of pH on inorganic carbon intake were examined through lipid analysis inthe cell of A. platensis according to pH. As a result, in the case of the effect of inorganic carbon intake of A. platensis according to pH on TAG content, pH 9 and pH 11 showed no significant difference in TAG content, but at pH 7, it was two times higher compared to pH 9 and pH 11. It was assumed that the reason why A. platensis excessively consumed inorganic carbon at pH 7 was because itincreased the TAG content in proportion to the intake of inorganic carbon to protect cells from external pH stress. In addition, it is considered that the TAG content produced in proportion to the intake of inorganic carbon is because acetyl-CoA produced in the Calvin cycle is required for the synthesis of TAG.