• Analytical Science and Technology
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• v.18 no.4
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• pp.271-277
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• 2005

Urea in blood has been measured as an effective marker for diagnosis of renal function. Urea which is e end-product of nitrogen containing metabolites such as proteins is filtered through glomeruli of kidneys and then excreted as urine. If the renal function is deteriorated, the urea concentration in blood will be increased, from which the healthiness of renal function is judged. In order to improve the confidence of diagnosis results, the results must keep traceability chain to certified reference materials, which was certified by primary reference method. In this study, we proposed isotope dilution-liquid chromatography/mass spectrometry (ID-LC/MS) as a candidate primary method, in which $15^N_2$-urea is used as an internal reference material. The developed method is highly accurate in principle and is convenient as it does not require cumbersome derivatization. 0.1 mmol/L ammonium chloride was selected as a mobile phase for HPLC because it provided low interference in MS analysis of relatively low molecular weighted urea. HPLC and MS were connected with an electrospray ionization (ESI) interface of positive mode, which provided high sensitivity and reproducibility. The developed method was validated with internationally recognized reference materials, and we have obtained satisfactory results in an international ring trial. The expanded uncertainty calculated according to ISO guide was 1.8% at 95% confidence interval. The developed method is being used as a primary reference measurement method such as for certification of serum certified reference materials (CRMs).

• Korean Journal of Clinical Laboratory Science
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• v.37 no.3
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• pp.178-184
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• 2005

Carry over contamination has been reduced in some systems by flushing the internal and external surfaces of the sample probe with copious amount of diluent. It between specimens should be kept as small as possible. A built-in, continuous-flow wash reservoir, which allows the simultaneous washing of the interior and exterior of the syringe needles, addresses this issue. In addition, residual contamination can further be prevented through the use of efficient needle rinsing procedures. In discrete systems with disposable reaction vessels and measuring cuvets, any carry over is entirely caused by the pipetting system. In analyzers with reuseable cuvets or flow cells, carry over may arise at every point through which high samples pass sequentially. Therefore, disposable sample probe tips can eliminate both the contamination of one sample by another inside the probe and the carry over of in specimen into the specimen in the cup. The results of the applicative carry over experiment studied on 21 items for total protein (TP), albumin (ALB), total bilirubin (TB), alkaline phosphatase (ALP), aspratate aminotranferase (AST), alanine aminotranferase (ALT), gamma glutamyl transferase (GGT), creatinine kinase (CK), lactic dehydrogenase (LD), creatnine (CRE), blood urea nitrogen (BUN), uric acid (UA), total cholesterol (TC), triglyceride (TG), glucose (GLU), amylase (AMY), calcium (CA), inorganic phosphorus (IP), sodium (Na), potassium (K), chloride (CL) tests in chematology were as follows. Evaluation of process performance less than 1% in all tests was very good, but a percentage of ALB, TP, TB, ALP, CRE, UA, TC, GLU, AMY, IP, K, Na, and CL was 0%, implying no carry over. Other tests were ALT(-0.08%), GGT(-0.09%), CK(0.08%), LD(0.06%), BUN(0.12%), TG (-0.06%), and CA(0.89%).

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.475-483
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• 2019

Special chemical warfare agents are lethal gases that attack the human respiratory system. One of such gases are blood agents that react with the irons present in the electron transfer system of the human body. This reaction stops internal respiration and eventually causes death. The molecular sizes of these agents are smaller than the pores of an activated carbon, making chemical adsorption the only alternative method for removing them. In this study, we carried out a Computational Fluid Dynamics simulation by passing a blood agent: cyanogen chloride gas through an SG-1 gas mask canister developed by SG Safety Corporation. The adsorption bed consisted of a Silver-Zinc-Molybdenum-Triethylenediamine activated carbon impregnated with copper, silver, zinc and molybdenum ions. The kinetic analysis of the chemical adsorption was performed in accordance with the test procedure for the gas mask canister and was validated by the kinetic data obtained from experimental results. We predicted the dynamic behaviors of the main variables such as the pressure drop inside the canister and the amount of gas adsorbed by chemisorption. By using a granular packed bed instead of the Ergun equation that is used to model porous materials in Computational Fluid Dynamics, applicable results of the activated carbon were obtained. Dynamic simulations and flow analyses of the chemical adsorption with varying gas flow rates were also executed.

• The Korea Journal of Herbology
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• v.36 no.6
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• pp.27-37
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• 2021

Objectives : In the current study, we performed the 13-week repeated oral dose toxicity test and a 4-week recovery test of standardized Cornus officinalis Sieb. et Zucc. and Psoralea corylifolia L. 30 % ethanol extract (SCP) in Sprague-Dawley (SD) rats owing to aims for verifying no observed adverse effect level (NOAEL). Methods : The animal study was performed according to OECD guidelines for the testing of chemicals section 4 health effects test No.408 repeated dose 90-day oral toxicity study in rodents (03 October 2008). In the repeated dose toxicity study, SCP was orally administered to female and male rats at dose levels of 1,000, 2,000, and 4,000 mg/kg/day for 13-week. The control group and high dose (4,000 mg/kg/day) group were then monitored for 4 extra weeks to determine recovery time after the study period. 1) Results : Compared with the control group, there were no treatment-related adverse effects in clinical signs, body weight, hematology, serum biochemistry (Aspartate aminotransferase, Alanine aminotransferase, Alkaline phosphatase, 𝛾-Glutamyl transpeptidase, Blood urea nitrogen, Creatinine, Glucose, Total cholesterol, Total protein, Creatine phosphokinase, Albumin, Total bilirubin, Triglyceride, Inorganic phosphorus, Albumin/Globulin ratio, Calcium ion, Sodium ion, Potassium ion, Chloride ion), necropsy findings and organ weight (Ovary, Adrenal gland, Pituitary, Thymus, Prostate, Testis, Epididymis, Spleen, Kidney, Heart, Lung, Brain, Liver) at any dose tested. Conclusions : Taken together, these results suggest that the NOAEL of SCP in both genders was considered as over 4,000 mg/kg. Results from this study provide scientific evidence for the safety of SCP.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1308-1314
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• 1999

The effects of modified atmosphere(MA) packaging and coating on the quality of mushroom (Agaricus bisporus) were investigated. Whole mushrooms(100 g) were packed with polyvinyl chloride(PVC) film wrap, PD941 and PD961 film bags and were stored in a chamber at $12^{\circ}C$ and 80% RH for 6 days. Gas composition of packages, respiration rate, weight loss, color and maturity index of MA packaged mushrooms were examined. The wrap packaged mushrooms showed different level of internal $CO_2$ concentrations among water washed, chitosan coated and $CaCl_2$ coated subgroups significantly at 5% level. The maximum $CO_2$ concentration of PD941 and PD961 packages for all coated showed $4.1{\sim}4.7%$ and $10.4{\sim}11.7%$, respectively, for the first day. PD961 package showed the lowest $O_2$ concentration compared to other groups. There were no significant respiration rate differences between wrap packed and PD941 packaged. Respiration rate of water washed. chitosan coated and $CaCl_2$ coated in PD961 packaged was 192 mg, 226 mg and 245 mg, respectively. Maturity index of PD961 packaged were not significantly different among the water washed, chitosan and $CaCl_2$ coated packages. Chitosan coating showed a negative effect on color change of mushrooms. The weight loss of 961 packaged was lower $(7.0{\sim}8.0%)$ that those of wrap packaged and PD941 packaged.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.3
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• pp.153-161
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• 2002

The installation of subsurface drainage equipment is required for generalized use of paddy field and to improve soil productivity. The internal drainage of paddy field has improved root condition from the increasing of oxygen supply and removing noxious elements. This experiment was carried out to determine the effects of fertilization and drainage system on soil characteristic, growth and lodging trait of rice in paddy soil. A subsurface drainage system was installed a depth of 0.8m. Three fertilizer treatments were applied : 1) Conventional fertilized plot, 2) Controlled-release fertilized plot, 3) No-fertilized plot. In conventional plot, 110 kg N (as urea 46%), 45 kg P (as fused phosphate 20%) and 57 kg K (as potassium chloride 60%) per hectare fertilizers were applied. Controlled-release fertilizer was applied by 70% of N compared to the conventional plot. During the rice cropping, the water depth decrease was two times higher in subsurface drainage(SD) plot than non-drained(ND) plot. After harvesting of rice, the bulk density of sub-soil(10-20cm depth) was lower in SD plot than ND plot. After the experiment, the surface soil pH was high at SD plot but sub-soil was high at ND plot. Organic matter content was higher in all soil layer for SD plot than fro ND plot. Available $P_2O_5$ was not different between SD and ND plot for surface soil, but was high for SD plot for sub soil. The $NH_4{^+}-N$ content of soil, shoot dry matter, total nitrogen and $K_2O$ of rice plant were greater after panicle formation stage in SD plot. Total nitrogen content, $P_2O_5$ and $K_2O$ of rice root were high in SD plot after heading. Though the gravity center and 3rd internode length were greater, pulling force of rice root was higher in SD plot than ND plot. Rice yield in SD plot were low at conventional and controlled-release fertilized plot because of the greater field lodging, but yield in SD plot was high at no-fertilized plot. This study indicates that the fertilization level should be decrease on subsurface drainage system for rice cropping.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.98-105
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• 1994

The search for tumor-avid agents for use in nuclear medicine imaging or therapy is a field of ongoing importance. Metallothionein (MT) is an intracellular protein that binds many metals with isotopes having imaging or radiotherapeutic potential. The purpose of the study was to determine whether uptake of radioisotopes that bind to MT is increased in tumor. We measured the uptake of Cd-109 and Ga-67 in tumor and normal tissues of sarcoma-bearing mice. Tumors were grown subcutaneously in female Balb/C mice from cultured Balb/3T3 cells transformed by the Moloney murine sarcoma virus (MMSV). When the tumors reached about 1 cm in diameter, mice were injected subcutaneously with Cd-109 and Ga-67. Eighteen and seventy-two hours later, the mice were sacrified. Organs and tissues were removed, weighed, and activity per mg tissue determined by gamma well-counting. Uptake of Cd-109 by MMSV tumors exceeded that by normal tissues examined, with the exception of liver and kidney (the organs known to be richest in MT). The tumor-to-tissue ratios of uptake for Cd-109 were far greater than those for Ga-67 for many normal tissues of great importance in terms of background activity (bone, intestine, fat, muscle, and blood). We concluded that metals that bind to MT may be useful for oncologic imaging or rediotherapy of cancer.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.8-13
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• 2010

Bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) were obtained by a polymerization reaction of epichlorohydrin (ECH) with bisphenol A (BPA) or bisphenol F (BPF). These compounds are commonly used as monomers or additives such as a polymerization stabilizer and a hydrochloric acid scavenger of epoxy resin, polyvinyl chloride (PVC)-containing organosols and polyester lacquers, that are applied to the internal surface of most canned foods to impart chemical resistance. The unreacted BADGE, BFDGE and their reaction products migrating from epoxy resin, PVC-containing organosol and/or polyester lacquer-based food packaging materials into the foods have recently become an issue of great concern because of increased customer demand for safety. This study was conducted to develop a rapid and sensitive simultaneous analysis method based on HPLC/FLD and HPLC/APCI-mass and to evaluate the concentration of BADGE, BFDGE and their metabolites, BADGE $H_2O$, BADGE $2H_2O$, BADGE HCl, BADGE 2HCl, BADGE HCl $H_2O$, BFDGE $H_2O$, BFDGE $2H_2O$, BFDGE HCl, BFDGE 2HCl and BFDGE HCl $H_2O$ for 133 canned food samples. The method provided a linearity of 0.9997-0.9999, a limit of detection of $0.01-0.13\;{\mu}g/mL$, a limit of quantitation of $0.03-0.44\;{\mu}g/mL$ and a recovery (%) of 85.64-118.18. The number of samples containing BADGE, BFDGE or their metabolites were: 28/133 (21.1%), with levels of 0.400-0.888 mg/kg being observed for aqueous foods (19/133) and 0.093-0.506 mg/kg being observed for oily foods (9/133).

• Applied Microscopy
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• v.38 no.4
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• pp.293-306
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• 2008

The essential factor of acute respiratory distress syndrome (ARDS), an acute lung injury accompanied commonly by sepsis syndrome is accumulation of neutrophils in lung tissue. The study attempted to confirm whether a lung injury would be decreased with the anti-inflammatory effect of germanium by the treated germanium prior to the development of ARDS and whether nitric oxide influence in suppressing a lung injury. Test groups were divided in the following structure for experiment; CON that has been administered with sodium chloride to airway, LPS administered with endotoxin for 5 hours in the same amount and 5 hours of endotoxin administered Ge+LPS following 1 hours of pre-treated germanium. The result of a test using experimental animals, infilteration of neutrophils (p<0.001) in bronchoalveolar lavage fluid (BALF) was significantly decreased, the structure of lung tissue was preserved relatively well, and much neutrophils with distinct positive were observed on tunel staining which showed increase of apoptotic neutrophils in the pre-treated germanium group compare to the endotoxin administrated group. In observation of ultrastructural changes of cell in BALF, phagocytic alveolar macrophage was increased in alveolar space, the nucleus of most engulfed neutrophils were condensed, and some apoptosis neutrophils appears to be DNA fragmentation and effacement of cellular organelles were found in intercellular matrix in the pre-treated germanium group. However, the nitric oxide showed increase in all the groups excluding CON, and the nitric oxide effect such as degranulation diminishing of mast cells and apoptosis increase of neutrophils in the pre-treated group only. The situation appears that there was change in internal environment of the experimental animal by the pre-treated germanium before the nitric oxide is produced and the anti-inflammatory effect activated the pre-processed germanium by nitric oxide which activated following the change. Therefore, the nitric oxide created from macrophage in accordance with the pre-treated germanium appears to influence in alleviating a lung injury. Accordingly, acute lung injury is alleviated by the anti-inflammatory effect of germanium such as inhibition of neutrophils migration, induction of neutrophil apoptosis and increase of phagocytic function of phagocyte, and the nitric oxide produced from activated macrophage by germanium would influence in suppressing a lung injury.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.4
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• pp.361-368
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• 2021

The objective of this study was to establish technology for removing bacteria with human- and eco-friendly material. Staphylococcus aureus as an important component for balanced equilibrium among microbiomes, was cultured under various concentrations of phosphate. Experimental observation relating to physical properties was performed in an addition of phosphate buffer. Statistically minimum value of size and hardness using atomic force microscope was observed on the matured biofilm at 5 mM concentration of phosphate. As a result of absorbance for the biofilm tagged with dye, concentration of biofilm was reduced with phophate, too. To identify whether this reduction by phosphate at the 5 mM is caused by counter ion or not, sodium chloride was treated to the biofilm under the same condition. To elucidate components of the biofilm counting analysis of the biofilm using time-of-flight secondary ion mass spectrometry was employed. The secondary ions from the biofilm revealed that alteration of physical properties is consistent to the change of extracellular polymeric substrate (EPS) for the biofilm. Viscoelastic characterization of the biofilm using a controlled shear stress rheometer, where internal change of physical properties could be detected, exhibited a static viscosity and a reduction of elastic modulus at the 5 mM concentration of phosphate. Accordingly, bacteria at the 5 mM concentration of phosphate are attributed to removing the EPS through a reduction of elastic modulus for bacteria. We suggest that the reduction of concentration of biofilm induces dispersion which assists to easily spread its dormitory. In conclusion, it is elucidated that an addition of phosphate causes removal of EPS, and that causes a function of antibiotic.