• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.291-299
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• 1997

In order to establish optimal dosage schedules and withdrawal times for sulfamethazine(SMZ) in pigs, pharmacokinetic and tissue distribution experiments were conducted in pigs. For comparative purposes, tissue depletion kinetics are also studied in rats. From three pigs administered with SMZ i.v., the pharmacokinetic profile of SMZ in two pigs was adequately described by a one-compartment open model whereas that in one pig was patterned after a two-compartment open model. Volume of distribution(Vd) was 0.48~0.57 L/kg and biological half-life($t_{1/2}$) was 11.8-16.8 h. From three pigs dosed with SMZ p.o., pharmacokinetic profile was explainable with a one-compartment open model. Time to reach maximum SMZ concentration in serum (Tmax) was 2.8 h, 3.2 h and 7.5 h. Elimination half-life was 2.8-7.5 h. The descending order in concentration of SMZ was plsama > kidney > liver > lung > heart > pancreas > spleen > duodenum > ileum > brain > adipsoe tissue from three pigs sacrificed at 5h, 29h and 54h after the administration of SMZ, p.o.. The protein binding of SMZ in pigs was 55.2%($2.5{\mu}g/ml$), 71.5% ($5{\mu}g/kg$) and 71.5%($10{\mu}g/ml$). The mean systemic bioavailability (F) of SMZ p.o. was 49.1 %. Meanwhile the pharmacokinetic profile of SMZ in rats was adequately described by a one-compartment open model. Absorption of SMZ p.o. in the rat was very rapid. In conclusion, the oral optimal dosage regimen of SMZ for pigs was the initial dose of 45.7 mg/kg followed by the maintenance dose of 30.2 mg/kg for high specific pathogens to SMZ. The time to reach below the stipulated residual allowable concentration (0.1 ppm) was calculated 93 h after oral administration of 200 mg/kg recommended by manufactureres.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.3
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• pp.1-7
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• 2015

The objective of this study was to compare fecal microbes survival in soil between compost surface application and soil incorporation. The survival experiment was conducted in six styrofoam beds ($510{\times}325{\times}305(mm)$ in size) filled with sandy loam soil. A half of six boxes were received by compost surface application, while the other half were treated with compost-soil mixture. Duplicated surface and surbsurface soil (20 cm depth) samples were collected at various interval up to 50 days and analyzed for the determination of fecal coliforms and E. coli numbers. As expected, surface applied beds demonstrated two to three magnitudes order greater in both the study microorganisms as compared to soil incorporated beds. Microbial inactivation rate of soil surface was twice as great as subsurface soil condition probably due to exposure to sun light and environmental conditions including moisture loss. When rainfall occurred, microbes on the surface were transported into soil along with water movement. It was concluded that surface compost application may be easier to apply but pose higher risk of human exposure to microbes. Winter compost application may be favorable in alleviating health risk by giving some time for inactivation compared to spring application.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1783-1789
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• 2017

Thermostability is an important property of xylanase because high temperature is required for its applications, such as wood pulp bleaching, baking, and animal feedstuff processing. In this study, XynB from Thermobacillus composti, a moderately thermophilic gram-negative bacterium, was modified via site-directed mutagenesis (based on its 3D structure) to obtain thermostable xylanase, and the properties of this enzyme were analyzed. Results revealed that the half-life of xylanase at $65^{\circ}C$ increased from 10 to 50 min after a disulfide bridge was introduced between the ${\alpha}$-helix and its adjacent ${\beta}$-sheet at S98 and N145. Further mutation at the side of A153E named XynB-CE in the C-terminal of this ${\alpha}$-helix enhanced the half-life of xylanase for 60 min at $65^{\circ}C$. Therefore, the mutant may be utilized for industrial applications.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.2
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• pp.103-112
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• 2017

The combination of nanoparticle with radioisotope could give the in vivo information with high sensitivity and specificity. However, radioisotope labeling of nanoparticle is very difficult and radioisotopes have different physicochemical properties, so the radioisotope selection of nanoparticle should be carefully considered. $^{18}F$ was first option to be considered for labeling of nanoparticle. For the labeling of $^{18}F$ with nanoparticle, Prosthetic group is widely used. Iodine, another radioactive halogen, is often used. Since radioiodine isotopes are various, they can be used for different imaging technique or therapy in the same labeling procedures. $^{99m}Tc$ can easily be obtained as pertechnatate ($^{99m}{TcO_4}^-$) by commercial generator. Ionic $^{68}Ga$ (III) in dilute HCl solution is also obtained by generator system, but $^{68}Ga$ can be substituted for $^{67}Ga$ because of the short half-life (67.8 min). $^{64}Cu$ emits not only positron but also ${\beta}-particle$. Therefore $^{64}Cu$ can be used for imaging and therapy at the same time. These radioactive metals can be labeled with nanoparticle using the bifunctional chelator. $^{89}Zr$ has longer half-life (78.4 h) and is used for the longer imaging time. Unlike different metals, $^{89}Zr$ should use the other chelate such as DFO, 3,4,3-(LI-1,2-HOPO) or DFOB.

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.3-15
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• 2001

The ozone kinetics including ozone auto-decomposition. effect of pH, and solubility were investigated. Diesel decomposition process including TCE & PCE decomposition. effect of hydroxyl radical scavenger, effect of pH, and ozone/$H_2O$$_2$by ozonation process were also examined using deionized water, simulated groundwater. and actual groundwater. Reactions with deionized water and groundwater both stowed the second-order reaction rates, and the reaction rate was much higher in groundwater (half-life of 14.7 min) than in deionized water (hal(half-life of 37.5 min). The reaction rate was accelerated at high pH values in both waters. The use of ozone showed high oxidation rates of TCE. PCE and diesel. Though hydroxyl radical scavengers existing in groundwater were inhibitors for treating diesel, high pH condition and addition of hydrogen peroxide could accelerate to degrade diesel in groundwater, indicating ozone oxidation process could be applied to treating diesel contaminated-groundwater.

• Tuberculosis and Respiratory Diseases
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• v.38 no.4
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• pp.372-378
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• 1991

Some kinds of newer fluoroquinolone antibiotics are known to interact with theophylline, which is widely used as a potent bronchodilator in asthma or chronic obstructive lung disease. To evaluate the effect of enoxacin and ciprofloxacin on the metabolism of theophylline, aminophylline was administered intravenously in bolus (6 mg/kg) over 30 minutes to 6 healthy volunteers (age: $23.3{\pm}4.2$ year, body weight: $63.2{\pm}9.0\;kg$, height: $169.0{\pm}6.5\;cm$, female 3, male 3) before and after per oral 5-day medication of enoxacin and ciprofloxacin, respectively and we measured the level of theophylline in serum. The results were as follows: 1) Enoxacin and ciprofloxacin did not influence the volume of distribution significantly. 2) Enoxacin decreased the clearance of theophylline significantly (from $42.9{\pm}14.6\;ml/min$ to $30.1{\pm}6.3\;ml/min$: p<0.05), but ciprofloxacin did not cause significant decrease (to $32.8{\pm}6.2\;ml/min$: p>0.005). 3) Enoxacin increased the elimination half life of theophylline significantly (from $496{\pm}83\;min$ to $693{\pm}32\;min$: p<0.001), but ciprofloxacin did not cause significant increase (to $687{\pm}222\;min$: p>0.05). These results suggested that enoxacin influenced clearance and elimination half life significantly and thorough monitoring of the level of theophylline in patients with coadminstration of enoxacin and theophylline was necessary. In case of ciprofloxacin, the influence on the metabolism of theophylline was not statistically significant, but one exceptionally large decrease of the clearance and increase of the elimination halflife of theophylline suggested the necessity of monitoring of theophylline level during coadministration of ciprofloxacin and theophylline.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.488-493
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• 2011

Callus culture initiation of strawberry (Fragaria${\times}$ananassa Duch.) was investigated at different Murashige and Skoog (MS) medium strengths, types and concentrations of plant growth regulators, and incorporating a cold pretreatment period to determine the optimal nutritional and environmental conditions. No high quality callus was induced on MS media without auxin regardless of medium strength. When 6-benzylaminopurine (BA) was combined with indole acetic acid (IAA), naphthalene acetic acid (NAA), and 2,4-dichlorophenoxyacetic acid (2,4-D), high quality callus were highly induced compared to medium supplemented with auxin alone. When $0.5mg{\cdot}L^{-1}$ BA was combined with IAA, NAA, and 2,4-D, high quality callus induction was more effective than the medium supplemented with the other BA concentrations. The best combination of auxin and cytokinin for high quality callus induction was $1.0mg{\cdot}L^{-1}$ NAA and $0.5mg{\cdot}L^{-1}$ BA. Although the differences in callus induction were not significant, high quality callus induction at half strength MS medium was more effective than at full strength medium. When $30g{\cdot}L^{-1}$ sucrose was added to the half strength MS medium, the rate of high quality callus induction increased. The optimum cold pretreatment temperature and period for high quality callus induction were $4^{\circ}C$ and 72 h, respectively. Regeneration rate of high quality callus increased in MS medium supplemented with thidiazuron.

• Korean Journal of Environmental Agriculture
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• v.1 no.2
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• pp.89-92
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• 1982

Persistence of cyanofenphos on Chinese cabbage under the different climate conditions was studied by spraying the insecticide at the rate of 0.5 and 0.75 ㎏ AI/ha at 22 and 36 days after transplanting and monitoring its residues upto 35 days after the final spray. At both spraying rates the degradation patterns of the insecticide, regardless of climate condition, showed similar trends; cyanofenphos residues on Chinese cabbage declined rapidly upto 14 days after the final spray but more slowly thereafter. Half-life for cyanofenphos on Chinese cabbage was $6{\sim}7$ days. The half-life was little affected by the spraying rate and time. Based on the FAO/WHO maximum residue limit of cyanofenphos on common cabbage (2 ppm), it is recommended that the pre-harvest intervels of the insecticide on Chinese cabbage could be 16 and 19 days for 0.5 and 0.75 ㎏ AI/ha, respectively.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.71-78
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• 2019

Nuclear imaging is one of the most powerful measures for non-invasive diagnosis of myocardial vascular disease. Radionuclide such as ¹³N, ¹⁵O, ²⁰¹Tl and ⁸²Rb is used for the measurement of cardiac blood flow. ¹³N, ¹⁵O and ²⁰¹Tl are produced in cyclotrons while ⁸²Rb is obtained from generator. Rubidium (Rb), an alkali ion, behaves biologically like potassium, and accumulates in myocardial tissue. Rb has rapid blood clearance profile which allows the use of ⁸²Rb with a short physical half-life of 75 s for non-invasive evaluation of regional myocardial perfusion. There are several advantages of ⁸²Rb over other radioisotopes. An ultra-short half-life significantly reduces the exposure of patients to radiation and allows to repeat injections for studying the effects of medical intervention. As a positron emitter, ⁸²Rb allows positron emission tomography (PET) imaging which have shown superior diagnostic performances. ⁸²Rb can be produced from generator by decay of its parent ⁸²Sr. However, the preparation of ⁸²Sr is difficult, because appropriate purity is required to meet the specification of the product. Recently reported procedure from ARRONAX research institute showed that a Chelex-100 resin is sufficient for this purpose and additional column is not necessary. Whereas Brookhaven National Laboratory (BNL) procedure contains three ion exchange resin separation, including Chelex-100 resin. Currently, since ⁸²Sr production site is non-existent in Korea, Korea Atomic Energy Research Institute (KAERI) has plan to produce ⁸²Sr within specifications. We compared ⁸²Sr purification procedures reported from ARRONAX and BNL to investigate the most suitable procedure for our conditions.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.215-218
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• 2008

To investigate the possible interaction between rutaecarpine and phenobarbital in rats, phenobarbital in saline at 80 mg/kg was given ip to male SD rats for 3 consecutive days. Saline was given to control animals. One day after phenobarbital pre-treatment, rutaecarpine at 16 mg/kg was administered through penile vein. Blood was collected and analyzed by using HPLC. The pharmacokinetic parameters were determined with the non-compartmental model. Pre-treatment with phenobarbital significantly altered the pharmacokinetic profiles of rutaecarpine and its metabolite, 10-hydroxyrutaecarpine. The AUC of rutaecarpine was reduced to approximately 50% of control and the plasma half-life of rutaecarpine was significantly shortened when compared with control. In addition, the Cmax of 10-hydroxyrutaecarpine was increased approximately 160% of control. The AUC and the plasma half-life of 10-hydroxyrutaecarpine were decreased to 76.9% of control and to 82.7 min from 175.9 min, respectively. The results suggested that phenobarbital might accelerate the metabolism of rutaecarpine, thereby changing the pharmacokinetic parameters of rutaecarpine in male SD rats.