• Journal of Biosystems Engineering
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• v.31 no.6 s.119
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• pp.463-473
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• 2006

Automated sensing of soil macronutrients would allow more efficient mapping of soil nutrient spatial variability for variable-rate nutrient management. The capabilities of ion-selective electrodes for sensing macronutrients in soil extracts can be affected by the presence of other ions in the soil itself as well as by high concentrations of ions in soil extractants. Adoption of automated, on-the-go sensing of soil nutrients would be enhanced if a single extracting solution could be used for the concurrent extraction of multiple soil macronutrients. This paper reports on the ability of the Kelowna extractant to extract macronutrients (N, P, and K) from US Corn Belt soils and whether previously developed PVC-based nitrate and potassium ion-selective electrodes could determine the nitrate and potassium concentrations in soil extracts obtained using the Kelowna extractant. The extraction efficiencies of nitrate-N and phosphorus obtained with the Kelowna solution for seven US Corn Belt soils were comparable to those obtained with IM KCI and Mehlich III solutions when measured with automated ion and ICP analyzers, respectively. However, the potassium levels extracted with the Kelowna extractant were, on average, 42% less than those obtained with the Mehlich III solution. Nevertheless, it was expected that Kelowna could extract proportional amounts of potassium ion due to a strong linear relationship ($r^2$ = 0.96). Use of the PVC-based nitrate and potassium ion-selective electrodes proved to be feasible in measuring nitrate-N and potassium ions in Kelowna - soil extracts with almost 1 : 1 relationships and high coefficients of determination ($r^2$ > 0.9) between the levels of nitrate-N and potassium obtained with the ion-selective electrodes and standard analytical instruments.

• Preventive Nutrition and Food Science
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• v.15 no.1
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• pp.24-29
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• 2010

This study was conducted to investigate sodium and potassium balances, as well as correlations among the relating factors in adult males and females. We collected blood, urine and feces samples as well as a dietary intake survey from 50 subjects. Then, we analyzed the sodium and potassium contents in blood, urine and feces, and evaluated their state of balance. The average ages of the study targets were 24.7 years old for males and 22.8 years old for females. The daily energy intake by the males was 1733.4 kcal and by the females was 1570.3 kcal. Sodium intakes were 138.3 mEq and 127.5 mEq for males and females, respectively. Potassium intakes were 43.1 mEq and 49.3 mEq, respectively. The daily excretions of sodium through urine were 136.6 mEq by males and 97.0 mEq by females and the excretions through feces were 2.2 mEq and 2.0 mEq, respectively. The daily excretions of potassium through urine were 20.2 mEq and 16.5 mEq by males and females respectively, and the excretions through feces were 7.7 mEq and 7.5 mEq male to female. The retention rates of sodium were 11.7% and 14.1% male to female, respectively, and the apparent absorption rates were 98.5% and 97.8%. Additionally, the retention rates of potassium were 32.9% and 39.8% and the apparent absorptions were 81.9% and 81.3%, both male and female. It was noted that, overall, the sodium intake of adult males and females is still higher than the recommended daily sodium intake, while the potassium intakes and excretions were found to be lower. Based on the results of this study, nutritional guidance and education is recommended to encourage decreased sodium intake and increased potassium intake, according to recommended standards.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.2
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• pp.73-77
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• 2003

The effects of nitric oxide on the vestibular function recovery following unilateral labyrinthectomy (UL) were studied. Sprague-Dawley male rats, treated with nitric oxide liberating agent sodium nitroprusside (SNP) and NOS inhibitor $N^G$-nitro-L-arginine methyl ester (L-NAME), were subjected to destruction of the unilateral vestibular apparatus, and then spontaneous nystagmus was observed in the rat. To explore the effects of nitric oxide on the neuronal excitability, whole cell patch clamp technique was applied on isolated medial vestibular nuclear neurons. The frequency of spontaneous nystagmus in SNP treated rats was lesser than that of spontaneous nystagmus in control animals. In contrast, pre-UL treatment with L-NAME resulted in a significant increase in spontaneous nystagmus frequency. In addition, SNP increased the frequency of spontaneous action potential in isolated medial vestibular nuclear neurons. Potassium currents of the vestibular nuclear neurons were inhibited by SNP. After blockade of calcium dependent potassium currents by high EGTA (11 mM) in a pipette solution, SNP did not inhibit outward potassium currents. 1H-[1,2,4] oxadiazolo [4,3-a] quinozalin-1-one (ODQ), a specific inhibitor of soluble guanylyl cyclase, inhibited the effects of SNP on the spontaneous firing and the potassium current. These results suggest that nitric oxide after unilateral labyrinthectomy would help to facilitate vestibular compensation by inhibiting calcium-dependent potassium currents through increasing intracellular cGMP, and consequently would increase excitability in ipsilateral vestibular nuclear neurons.

• KSBB Journal
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• v.30 no.3
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• pp.97-102
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• 2015

This study aimed to evaluate the potential plantgrowth promoting effects of potassium polyacrylate, a superabsorbent polymer, and Bacillus sp. SH1RP8, a family of plant-growth-promoting bacteria. Potassium polyacrylate was selected as the polymer for use due to its high molecular weight and its ability to retain and continuously supply moisture. Plant-growth-promoting rhizobacteria (PGPR) were isolated from the soil and applied to plants growing in dry environments, such as saline conditions. The moisture absorption and retention abilities of potassium polyacrylate were evaluated at a high temperature ($50^{\circ}C$) and in a dry condition, during which time the polymer showed a water retention potential of 19606.07% after 29 days. To overcome the reaming problem in the soil environment, natural polymers (such as cellulose) were mixed with the potassium acrylate. The shoot growths of Peucedanum japonicum Thunb and Arundo donax were significantly enhanced when treated with the mixture of the isolated rhizosphere bacterium SH1RP8 and potassium polyacrylate (63.5 and 124.3%, respectively).

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.216-225
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• 1991

The purpose of this study was to evaluate the desensitizing effect of potassium oxalate(Group I), sodium fluoride (Group II), and control group (Group III). The 120 teeth of 26 patients who had been complained dentinal hypersensitivity were divided into three groups by applicating agent. The observation was done before and immediately after treatment. The data were statistically analyzed and the results were as followed. 1. Potassium oxalate showed the best desensitizing effect to the stimuli, followed by sodium fluoride, control group, and there was a significant difference (p<0.05) in desensitizing effect among the groups. 2. Potassium oxalate showed the best desensitizing effect to the stimuli, followed by sodium fluride, control group on both cervical abrasion and gingival recession, and there was a significant difference (p<0.05) in desensitizing effect among the groups on both cervical abrasion and gingival recession. 3. There was no significant difference (p<0.05) in effect of the desensitization between cervical abrasion and gingival recession. 4. The scratch and air blast I were more effective in desensitiziation than other stimuli with significant difference (p<0.05). In view of the results mentioned above, it can be conceived that potassium oxalate is more effective than sodium fluoride on the reduction of dentinal hypersensitivity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.493-501
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• 1995

To investigate an effect of dietary sodium and potassium on blood pressure, 418 adolescents living in Kangwha area were studied. Two measurements were taken on each blood pressure(diastolic, systolic) and the average of the two readings was used in the analysis. Sodium and potassium intake were estimated by the determination of those electrolytes in 24hr urine. Not only dietary factors but also physical growth factors such as weight, height, arm-circumference and skinfold-thickness were induced in the stepwise multiple regression analysis to indentify the relative importance between the factors. The variation of blood pressure both in systolic and diastolic in both sexes was inconsistent with the levels of sodium and potassium intake. The results of multiple regression analysis showed that the physical growth were more influential than nutrient factor. It suggested that hypertension risk factors observed form the adults, may not be identical with that of the growing aged population. After control of the physical growth, there was no significant variation observed by the level of sodium and potassium intake on blood pressure. In summary, the results indicate that growth has been more influential than dietary factor on blood pressure for growing aged population.

• Journal of the Korean institute of surface engineering
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• v.48 no.5
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• pp.233-237
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• 2015

In order to investigate the potassium (K) gettering, Al-1%Si/$SiO_2$/PSG multilevel thin films were fabricated. Al-1%Si thin films and $SiO_2$/PSG passivations were deposited by using DC magnetron sputter techniques and APCVD (atmosphere pressure chemical vapor deposition), respectively. Heat treatment was carried out at $300^{\circ}C$ for 5 h in air. SIMS (secondary ion mass spectrometry) depth profiling analysis was used to determine the distribution of K, Al, Si, P, and other elements throughout the $SiO_2$/PSG passivated Al-1%Si thin film interconnections. Potassium peaks were observed throughout the $SiO_2$/PSG passivation layers, and especially the interface gettering at the $SiO_2$/PSG and at the Al-1%Si/$SiO_2$ interfaces was observed. Potassium gettering in Al-1%Si/$SiO_2$/PSG multilevel thin films is considered to be caused by a segregation type of gettering.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.131-135
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• 2004

Oral supplementation with potassium permanganate (30, 50 and 100 $\mu\textrm{g}$) to fifth instar larvae of the ${CSR_2}{\times}{CSR_4}$ race of the silkworm, B. mori resulted in a significant increase in the glycogen content of the fat body and haemolymph trehalose. The protein content of the fat body is also significantly increased in all the potassium permanganate treated groups where as that of the haemolymph is significantly increased only in the 30 ${\mu}g4 fed group. The total lipids content of the fat body increased significantly in all the potassium permanganate treated groups. This indicates that the potassium permanganate may stimulate metabolic activity, there by influencing the biochemical contents in the fat body and haemolymph of the silkworm, B. mori.

• Journal of Nutrition and Health
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• v.34 no.1
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• pp.23-29
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• 2001

This study was conducted to investigate the concentrations and infants intake of sodium and potassium from human milk during the first 5 months of lactation. The sodium concentrations of the milk during the lactation appeared 21.1, 18.1, 15.9, 12.4, 10.6 and 11.4 mg/100g at 0.5, 1, 2, 3, 4, and 5 months of lactation respectively. The potassium concentrations of the milk 48.5, 43.3, 40.8, 39.9, 40.5 and 38.5 respectively, Na/K ratio of the milk were 0.76, 0.75, 0.70, 0.56, 0.46 and 0.53(mEqu\\mEq). Sodium intakes of breast-fed infants were 106.9, 108.4, 90.6, 82.5 and 95.6mg/day during the lactation. Potassium intakes of the infants were 255.7, 276.0, 289.7, 294.6, 320.3 and 318.3mg/day. Sodium and potassium concentrations in infant formula averaged 23.62 and 67.61 mg/100g which was 1.90 and 1.69 times as those of breast milk at 3 month of lactation. Commercial whole milks had 39.53 and 135.22mg/100g of sodium and potassium respectively which was 3.19 and 3.39 times as those of the milk. From this study, reevaluation of sodium and potassium intakes if breast-fel infants was merited and the regulation of that minerals in infant formula is need to lower the renal solute load of formula-fed infants.(Korean J Nutrition 34(1):23-29, 2001)

• Journal of Nutrition and Health
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• v.18 no.3
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• pp.201-208
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• 1985

The purpose of this study was to estimate the sodium and potassium intakes of university students in Korea and to evaluate the relationship between blood pressure and related variables. Two hundred and eighty five subjects were selected from among healthy university students aged 17 to 28. The urinary (sodium, potassium urea nitrogen and creatinine) excretions in 24 hrs. were evaluated from the analysis of urine samples gathered for 12hrs. At the same time, dietary intakes of sodium and potassium were assessed by the modified convenient method with the same subjects. The results were as follows : 1) The urinary sodium excretions of male and female students in 24hrs. were estimated at 199.1mEq and 174.5mEq respectively. Daily sodium intakes by the questionnaire were calculated to be 218.5mEq for male students and 218.1mEq for female students. 2) The urinary potassium excretions in male and female students were 48.3mEq/24hr and 43.9mEq/24hr. respectively, and the potassium intakes 48.6mEq/24hr. and 47.4mEq/24h. each 3) No correlations were found between blood pressure and the urinary excretions of sodium potassium or urinary Na/K ratio in college students.