• Applied Biological Chemistry
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• v.24 no.2
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• pp.112-119
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• 1981

The persistence of preemergence herbicides, butachlor [2-chloro-2,6-diethyl-N(butoxymethyl) acetanilide] and nitrofen(2,4-dichlorophenyl-4-nitrophenyl ether), at 10 ppm level in different soil conditions amended with organic matter and lime was studied under flooded and field moisture capacity. The microbial breakdown played a major role in the dissipation of the herbicides in soil. Nitrofen degradation in flooded soil was greatly accelerated, while it was slowed down in field moisture capacity as compared with butachlor. Increased amendment of rice straw to the soil shortened the half-life of butachlor under flooded condition, however it prolonged that of butachlor when the amendment was exceeded over 1% on dry weight basis. Liming the soil stimulated decomposition of the herbicides in the soil systems, which ap pears to be pH independent.

• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.29-35
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• 2007

Recently, due to narrow margin on design factor of flue gas desulfurization (FGD) systems or aging of systems, some problems such as decrease of $SO_2$ removal efficiency and difficulty on coping with unstable state are arising on FGD systems. On this study, to cope with these problems several methods such as adjustment of reagent pH, inlet $SO_2$ concentration, variation of units of operation pump, installation of liquid distribution ring (LDR) were attempted to increase the $SO_2$ removal using spray type simulated FGD system. Also, sulfite and Al/Fx ion effects on limestone blinding were experimented. When three absorber recirculation pumps were operated, $SO_2$ removal was increased by 12% in comparison with that of two pumps operation. $SO_2$ removal was increased by 2~7% after installation of LDR. Dissolved oxygen increased up to 0.5 ppm and limestone binding effect was alleviated after injection of dibasic acid (DBA) with the concentration of 500 and 1,000 ppm. When $Al^{3+}$ and $F^-$ ions were coexisting, the dissolution rate of limestone was decreased by 20%.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.349-355
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• 2022

In this study, we sought to identify a soil stabilizer that can be applied to paddy fields vulnerable to arsenic (As) pollution. To this end, we conducted a pot experiment in which we evaluated the effects of different stabilizers on the bioavailability of As in paddy soil. As candidate stabilizers, we assessed calcium superphosphate (CSP), sulfur, and steel slag, which were applied at the rates of 0.7 and 1.4, 0.1 and 0.2, and 7.0 and 14.0 Ma ha^-1, respectively. On day 67 after rice transplantation, we detected significantly lower concentrations of As in the solutions of paddy soil treated with 1.4 Ma ha^-1 CSP (96.9 ㎍ L^-1) and 0.2 Ma ha^-1 sulfur (207.2 ㎍ L^-1) compared with the As concentrations in control (314.5 ㎍ L^-1) and steel slag-treated (268.6-342.4 ㎍ L^-1) soil. Compared with the As concentrations in control brown rice (0.16 mg kg^-1), concentrations in brown rice were lowest in the pots treated with 1.4 Ma ha^-1 CSP (0.09 mg kg^-1). Furthermore, in response to CSP treatments, we detected increases in the weight of rice grains (50.0-50.4 g/pot) compared with the control (40.4 g/pot) and other treatments (26.9-48.1 g/pot), which we speculate could be attributed to the reduction in As toxicity to rice owing to a decline in soil solution As contents and the fertilization effect of the CSP treatment. Collectively, our findings indicate a high-level application of CSP (1.4 Ma ha^-1) to paddy soil has a comparatively beneficial effect in mitigating the bioavailability of As.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.576-587
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• 2010

Background: Effective decellularization and fixation process is critical, in order to use xenogenic valves clinically. In the present study, we decellularized bovine pericardium using sodium dodecyl sulfate (SDS) and N-lauroyl sarcosinate, treated with $\alpha$-galactosidase, and then fixed in various manners, to find out the most effective tissue preservation & fixation procedure. Material and Method: Bovine pericardium was decellularized with SDS and N-lauroyl sarcosinate, and treated with $\alpha$-galactosidase. Both groups were fixed differently, by varying glutaraldehyde (GA) or EDC (1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide)/N-hydroxysuccinamide (NHS) treatment conditions. Thereafter, physical examination, tensile strength test, thermal stability test, cytotoxicity test, pronase test, pronase-ninhydrin test, purpald test, permeability test, compliance test, H&E staining, DNA quantification, and $\alpha$-galactose staining were carried out to each groups. Result: GA fixed groups showed better physical properties and thermal stability than EDC/NHS fixed groups, EDC/NHS-GA dual fixed groups showed better physical properties and thermal stability than EDC/NHS fixed groups, and showed better thermal stability than GA fixed groups. In pronase test and pronase-ninhydrin test, GA fixed groups and EDC/NHS-GA dual fixed groups showed stronger crosslinks than EDC/NHS groups. Permeability and compliance tended to increase in EDC/NHS-GA dual fixed groups, compared to GA fixed groups. But, EDC/NHS-GA dual fixed groups had stronger tensile strength and lower cytotoxicity than GA fixed groups. Conclusion: We have verified that EDC/NHS-GA dual fixation can make effective crosslinks and lower the toxicity of GA fixation. Henceforth, we will verify if EDC/NHS-GA dual fixation can lower calcifications & tissue failure in vivo experiment.

• Applied Biological Chemistry
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• v.21 no.1
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• pp.58-62
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• 1978

Dry weight, and mineral content in leaves, stems, and roots of the ginseng plant (Panax ginseng C.A. Meyer) were investigated. The highest T/R ratio, 0.52, was observed in a four year old plant due to a vigorous growth of the plant at this age. Also the dry weight increase was rather higher in the younger root than the older one. Mineral content of the plant was rather higher in the younger root than the older one. Potassium content in leaves and stems was higher than those of nitrogen and phosphorus. Generally, the leaves contained more iron and manganese than any other micronutrients. The iron content amounted to $1,000{\sim}2,000ppm$ in leaves. Zinc content was higher in stems and leaves than roots especially in stems of the younger roots. Total amount of the up-taken N, $P_2O_5$, and $K_2O$ per 10a in six years was 10.2kg, 2.3kg and 14.9kg respectively, indicating the considerable abounts of $K_2O$ was absorbed.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.2
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• pp.144-150
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• 2015

Early treatment is recommended for class III malocclusion in the primary dentition, though it is difficult to diagnose correctly. It was recommended dental maturation can possibly be used to make a differential diagnosis of skeletal class III malocclusion. This study aimed to compare dental maturation of first molars in children with skeletal or non-skeletal class III malocclusion in the primary dentition and to determine if dental maturation could be used to make a differential diagnosis of class III malocclusion. Among the children visiting the department of pediatric dentistry in Pusan National University Dental Hospital for anterior crossbite in the primary dentition, 18 were categorized into the non-skeletal class III malocclusion and 34 into the skeletal class III malocclusion. Panoramic radiographs were used to make comparative analysis of dental age and the eruption rate of the first molars. The following results were obtained. No difference was found between chronologic and dental age by the skeletal features or gender, with the latter being older than the former (p < 0.05). The discrepancies in eruption rate of first molars were significantly different between skeletal (18.91%) and non-skeletal groups (16.53%) (p < 0.05). This result implies that maturation of the first molars might be used to make a differential diagnosis of class III malocclusion.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.7
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• pp.813-820
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• 2010

The vertical roller mill is important for machine grinding and mixing various crude materials in the process of producing Portland cement. A vertical roller mill is subjected to cyclic bending stress because of the roller load. Because of the cyclic bending stress, only $4{\times}10^6-8{\times}10^6$ cycles are achieved instead of $4{\times}10^7$ cycles. The stress also causes fractures at the edge of grinding path of the outer roller. The expenses incurred in repairing the grinding path amounts to 30% of the total maintenance cost. Therefore, it is desirable to redesign the vertical roller mill in order to reduce the expenses incurred in repairing the roller. In this study, artificial neural networks (ANNs) were applied in order to solve the multiobjective optimization problem for vertical roller mills by using the function approximation ability of ANNs. To learn and generalize ANNs, the maximum and minimum stresses were estimated from the results of the finite-element analysis of a vertical roller mill. Thus, ANNs could be applied to solve the multiobjective optimization problem.

• Journal of Chest Surgery
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• v.30 no.8
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• pp.819-822
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• 1997

Aortic valve replacement with aortic allograft has been considered a treatment of choice for aortic valve disease secondary to bacterial endocarditis because of its good homodynamic performance and higher resistance to infection. The aortic root replacement technique might be superior to the subcoronary allograft implantation technique with regard to aortic regurgitation. A 46 yea,rs old male patient had acute aortic regurgitation with progressing heart failure secondary to acute bacterial endocarditis. The patient underwent emergent aortic root replacement using 20 mm aortic allograft. At operation, right coronary cusp perforation and heavy calcification of commissure between right and left coronary cusp were observed. The patient recovered well and postoperative echocardiography demonstrated no aortic regurgitation. Inflammatory signs were subsided after 8 weeks of antibiotics therapy. Medically uncontrolled acute bacterial endocarditis was treated successfully by aortic root replacement using aortic homograft.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.555-561
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• 1998

Hypophosphatasia is a rare metabolic disorder which manifests characteristics such as abnormal mineralization of bone and dental tissues, diminished serum and tissue alkaline phosphatase, and increased urinary secretion of PEA. It inherited as an autosomal recessive or dominant trait and occurs in all races. In general, hypophosphatasia can be classified in 4 subtypes which are the perinatal, infantile, childhood, adult type depending upon the age at presentation and severity. In young children with Hypophosphatasia the long bones show irregular defects, and the skull showes poor calcification. In older children with premature closure of the skull sutures there may be multiple lucent area called gyral or convolutional markings, described as resembling beaten copper, presumably resulting from increased intracranial pressure. Examination of the jaws reveals a generalized lucency of the maxilla and mandible. the cortical bone and lamina dura are thin, and the alveolar bone may be deficient. Clinical features of Hypophosphatasia include premature loss of deciduous teeth, especially incisors, hypoplasia or aplasia of root cementum, enamel hypoplasia, irregular calcification of dentin, large pulp chamber, and resorption of marginal alveolar bone and roots. Our report involves a patient with a chief complaint of early loss of both Mx. and Mn. deciduous incisors. After conducting a through clinical and radiographic examination this patient was referred to pediatrics under the suspicion of hypophosphatasia, the diagnosis proved to be correct and successful results were accomplished through a denture made to improve esthetics and function.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1146-1151
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• 2023

Medullary thyroid carcinoma (MTC) is a rare malignancy that originates from the parafollicular cells of the thyroid gland. Hashimoto's thyroiditis (HT) is an autoimmune thyroid disease and is the most common cause of hypothyroidism. Previous studies have frequently discussed the association among HT, papillary thyroid carcinoma, and thyroid lymphoma. However, there have been few reports on the ultrasonographic findings of concomitant HT and MTC. In the present case, a heterogeneous hypoechoic background parenchymal echogenicity, with intraglandular echogenic strands, and increased vascularity were observed. A concurrent, ill-defined, parallel-oriented, heterogeneous hypoechoic mass with central microcalcifications was located at the left thyroid gland, consistent with reported US findings of medullary thyroid carcinoma except for an ill-defined margin in our case.