• Archives of Pharmacal Research
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• v.19 no.6
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• pp.475-479
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• 1996

Diethylcarbamazine (DEC, 1-diethylcarbamyl-4-methylpiperazine) is an antiparasitic piperazine derivative used in the treatment of lymphatic filariasis caused by Wuchereria bancrofti, Brugia malayi or grugia timori. DEC-N-oxide is a major metabolite in humans and has antifilarial activity. In carrying out pharmacokinetic studies, gas chromatographic analysis of DEC in plasma can be complicated by the presence of the metabolite, since the thermally unstable DEC-N-oxide is converted back to a material which coelutes with DEC under the conditions of the analysis. We now report a method to separate DEC-N-oxide from DEC in plasma using solid phase extraction with subsequent gas chromatographic analysis using a nitrogen specific detector. One-diethylcarbamyl-4-ethylpiperazine (E-DEC) was the internal standard. The standard curve of DEC was linear in the range of 10 to 200 ng/ml as described by Y=0.0350+0.0128X, $R^2=0.999$. The limit of quantitation was 4 ng/mL. Reproducibility at 10, 100 and 200 ng/mL concentration points of the standard curve gave coefficient variations of 6.1%, 7.8% and 1.6%, respectively. The recovery following solid phase extraction was 99.3% for DEC and 94.8% for the internal standard. This sensitive and specific analytical method is suitable for pharmacokinetic studies of DEC.

• Journal of Korean Society of Forest Science
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• v.95 no.5
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• pp.585-590
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• 2006

In vitro-grown axillary shot-tip meristems of Lycium chinense Mill. from cold-acclimated plant were successfully cryopreserved using a vitrification technique. After loading for 15 minutes with a mixture of 2.0 M glycerol and 0.4 M sucrose ($20^{\circ}C$), small segments (1-2 mm, 3-4 mm, and 5-6 mm) were cut from axilary buds and exposed to the cryoprotectant solution containing 30% glycerol, 15% ethylen glycol,15% dimethyl sulfoxide (DMSO), and 0.4 M sucrose at $0^{\circ}C$ for 30-120 minutes prior to direct plunge into liquid nitrogen (LN). After rapid thawing ($40^{\circ}C$), the segments were washed with MS medium containing 1.2 M sucrose for 0-35 minutes, and then transferred onto recovery-growth medium. The highest survival rate (about 90%) was obtained with cold-hardening treatment, and cryopreserved explants were successfully recovered to plantlets. No abnormal morphological changes were observed with the recovered plants after cryopreservation.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.19-24
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• 2001

A solvent sublation has been studied for the determination of trace Au(III), Pt(IV) and Pd(II) in waste water with their complexes of 2-mercaptobenzothiazole (MBT). Experimental conditions such as the concentration of HCl, the amount of MBT as a ligand, the type and amount of surfactants, bubbling rate and time, and the type of organic solvent were optimized for the solvent sublation, i.e., 25.0 mL of 2.0 M HCl solution and 30mL of 0.4%(w/v) MBT ethanolic solution were added to a 1.0 L sample to form stable complexes. The addition of 4.0 mL of 1 ${\times}$$10^{-3}$ M CTAB (cetyltrimehtylammonium bromide) solution was needed for the effective flotation accomplished by bubbling nitrogen gas at the rate of 40.0 mL/min for 35 minutes. As a solvent, 20.0 mL of MIBK (methylisobuthylketone) was used to extract the floated complexes. The procedure was applied to three kinds of waste waters. Au(III) was determined as 0.68 ng/mL and 0.98 ng/mL respectively for final washed water of two plating industries in Banwol. Pd(II) and Pt(IV) were not detected in any of the three samples. The recovery, which was obtained with analyte-spiked samples, were 95-120%.

• International Journal of Industrial Entomology and Biomaterials
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• v.39 no.1
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• pp.34-38
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• 2019

In this study, we investigated the effect of silkworm, and its by-products on exercise endurance, muscle mass, and fatigue recovery using ICR mice model. Powders of silkworm, pupae, dongchunghacho, and silk powder were suspended in water and feed to mice for 2 weeks. The forced swimming time was increased by 4.3, 4.1 and 2.8 seconds after silkworm, pupae, and dongchughacho administration compared to DW fed group. Increases in exercise ability were achieved by difference mechanism according to feeding materials. Pupae increased muscle mass by 129% compared with the control group which may effect on elongation of swimming time. Dongchunghacho improved the plasma concentrations of fatigue markers such as creatinine, blood urea nitrogen (BUN), and D-lactate. Silkworm administration showed dual effect, the muscle mass induction (114% vs. control) and anti-fatigue (plasma creatinine, BUN, and D-lactate were 63, 75, and 78% vs. con) effect which contributed most elongated swimming time. In conclusion, silkworm and its by-products including pupae and dongchunghacho with the predominant protein and bioactive components improved muscle mass and showed anti-fatigue effect which could promote exercise performance ability.

• Nutrition Research and Practice
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• v.17 no.4
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• pp.660-669
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• 2023

BACKGROUND/OBJECTIVES: To investigate the effect and regulatory mechanism of resveratrol supplementation on the mitochondrial energy metabolism of rats with exercise-induced fatigue. MATERIALS/METHODS: Forty-eight Sprague-Dawley male rats were divided randomly into a blank control group (C), resveratrol group (R), exercise group (E), and exercise and resveratrol group (ER), with 12 rats in each group. Group ER and group E performed 6-wk swimming training with 5% wt-bearing, 60 min each time, 6 days a wk. Group ER was given resveratrol 50 mg/kg by gavage one hour after exercise; group R was only given resveratrol 50 mg/kg by gavage; group C and group E were fed normally. The same volume of solvent was given by gavage every day. RESULTS: Resveratrol supplementation could reduce the plasma blood urea nitrogen content, creatine kinase activity, and malondialdehyde content in the skeletal muscle, increase the total superoxide dismutase activity in the skeletal muscle, and improve the fatigue state. Resveratrol supplementation could improve the activities of Ca²⁺-Mg²⁺-ATPase, Na⁺-K⁺-ATPase, succinate dehydrogenase, and citrate synthase in the skeletal muscle. Furthermore, resveratrol supplementation could up-regulate the sirtuin 1 (SIRT1)-proliferator-activated receptor gamma coactivator-1α (PGC-1α)-nuclear respiratory factor 1 pathway. CONCLUSIONS: Resveratrol supplementation could promote mitochondrial biosynthesis via the SIRT1/PGC-1α pathway, increase the activity of the mitochondrial energy metabolism-related enzymes, improve the antioxidant capacity of the body, and promote recovery from exercise-induced fatigue.

• Journal of Korean Society of Water and Wastewater
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• v.38 no.2
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• pp.95-107
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• 2024

This study proposes the use of a cobalt-based Prussian blue analogue (Co-PBA; potassium cobalt hexacyanoferrate), as an adsorbent for the cost-effective recovery of aqueous ammonium ions. The characterization of Co-PBA involved various techniques, including Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, nitrogen adsorption-desorption analysis, and zeta potential. The prepared Co-PBA reached an adsorption equilibrium for ammonium ions within approximately 480 min, which involved both surface adsorption and subsequent diffusion into the interior. The isotherm experiment revealed a maximum adsorption capacity of 37.29 mg/g, with the Langmuir model indicating a predominance of chemical monolayer adsorption. Furthermore, the material consistently demonstrated adsorption efficiency across a range of pH conditions. Notably, adsorption was observed even when competing cations were present. Co-PBA emerges as a readily synthesized adsorbent, underscoring its efficacy in ammonium removal and selectivity toward ammonium.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.109-114
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• 1999

This study was carried out to obtain some information on the sustainability of paddy rice through the long-term variation of nitrogen use efficiency. The experiment was conducted during 30-year with the same amount of N, P, K and compost at Milyang, southern part of Korea. The results were as follows. Grain yield was increased significantly in the plots of compost incorporation only. However, yield productivity was decreased slightly in the plots with nil and unbalanced fertilization. The effects of rice straw compost on grain yield was not clear at the early crop years but was shown slightly at the late period of the experimental. The grain yield in the plots of compost incorporation at 30th crop year was come to about 80% of NPK plots. The amount of nitrogen uptaken by rice plant was the highest as $167kg\;ha^{-1}$ in NPK plus compost incorporation. Recovery efficiency)($RE_N$) was higher as 0.48~0.74 in compost incorporation plots than in other plots of balanced and unbalanced application. Average agronomic efficiency($AE-N$) and partial factor productivity from N fertilizer applied($PFP_N$) during 30 crop years in NPK plots was 12.8 kg/kg N and 37.7 kg/kg N, respectively, and difference of $AE-N$ and $PFP_N$ shown as indigenous soil nitrogen supply(INS) was higher as 28.4 kg/kg N in NPK + compost plot than NPK plot and was widened at the late period of experiment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.4
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• pp.385-393
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• 2011

Soybean is the most promising crop for substituting rice on the paddy field. Excessive water stress is a common limiting factor in soybean yield under paddy soil condition. This study was carried out to identify changes in leaf total nitrogen and petiole ureide content under excess water conditions for establishing a screening system related to waterlogging tolerance. Waterlogging treatment was conducted by maintaining the water level on the soil surface for 10 days at the early vegetative growth stage ($V_5$) and the flowering stage ($R_2$). Leaf total nitrogen content, SPAD value and ureide content in petiole decreased in all soybean varieties in response to waterlogging, but the degree of decrease was much lesser in Pungsannamulkong and Muhankong than in Jangyeobkong and Myungjunamulkong, at 21 days after waterlogging treatment. This result means that root and nodule recovery rates were much higher in Pungsannamulkong and Muhankong than in Jangyeobkong and Myungjunamulkong after waterlogging treatment. The ureide and leaf nitrogen content showed high positive correlation with SPAD value, regardless of waterlogged stages. In conclusion, leaf nitrogen content, ureide content in petiole and leaf greenness were identified as promising indicator for screening soybeans which are tolerant of excess water.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.123-131
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• 1986

This study was conducted to evaluate the effect of annual application of silicate fertilizer on rice yield and soil physico-chemical properties. Field experiment was done on the condition of fertilization of silicate fert. 150 and 250kg/10a to the clay loam paddy field for ten years from 1975 to 1984. Data for rice growth and nutrient uptake was analyzed for ten years base. The results obtained are as follows. 1. Average unhulled rice yield for 10 years increased at 16% in the treat of silicate fert. 150kg/10a annually applied in comparison with the N.P.K treated plot, but silicate fert. 250kg/10a treated plot was decreasing tendency somewhat in yield. 2. Amount of potassium uptake of rice straw at the harvesting stage was positively significant recognized with unhulled rice yield and straw yield of rice plant. 3. The amounts of N, $P_2O_5$ and $K_2O$ uptake in the treat of silicate fert. 150kg/10a were much more than those of silicate fert. 250kg/10a treated plot. However the treat of silicate fert. 250kg/10a increased the amounts of CaO, MgO and Silica uptake than other treats markedly. Especially the treat of silicate fert. 150kg/10a was higher in nitrogen recovery rate than other nutrients recovery rate, but the recovery of silica was low. 4. The treat of silicate fert. 250kg/10a annually applied markedly decreased the translocation rate of nitrogen, potassium and silica from straw to the unhulled rice grain. 5. Ten years' average value of soil O.M. content was much more in the treat of silicate fert. 150kg/10a which show higher yield increase than other treats, but in the treat of silicate fert. 250kg/10a, soil O.M. content was lower, however silicate content in soil was the most among other treats.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.829-846
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• 2015

This study was conducted to determine the effects of organic fertilization rates on the nutrient accumulation and recovery in radish (Raphanus sativus L.) as well as growth and yield of radish in Jeju island. An understanding the relationships between organic fertilization rate, crop nutrient recovery and crop yield can assist in making organic fertilizer recommendation which balances crop value and environmental risk in organic cultivation. Nitrogen (T-N), phosphate ($P_2O_5$) and potassium ($K_2O$) were applied at 0, 115-35-40, 230-70-80 (standard application rate), 460-140-160, 230-200-100 (recommended application rate) and 158-53-35 kg/ha (customary application rate), respectively as the broadcast application of mixed organic fertilizer (N 4.5% - $P_2O_5$ 1.5% - $K_2O$ 1%) in combination with langbeinite ($K_2O$ 22%), 100% at sowing period. The organic fertilizer was made of organic materials like oil cakes. Total yield of radish, as fresh weight of roots, increased with increasing organic fertilizer doses to a maximum at rate of standard or soil-testing application. Nitrogen, phosphate and potassium accumulations of radish increased curvilinearly with increasing organic fertilization rate to a maximum at rate of N 460 - $P_2O_5$ 140 - $K_2O$ 160 kg/ha. However, nitrogen, phosphate and potassium use efficiency of applied organic fertilizer decreased curvilinearly or linearly with increasing organic fertilization rate. Application of organic fertilizer in combination with langbeinite (as a potassium source) had significant effect on the yield of radish. Organic fertilization on a basis of standard or soil-testing application rate is recommended for maximun radish yield in organic cultivation.