• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.236-241
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• 1988

The responses of GA$_3$ treatment on the culm length, internode elongation, number of internodes elongated and on the panicle length of 115 Japonica rice cultivars were studied. One spray with 50 ppm GA$_3$ was made at about 30 days before heading. Generally short culm cultivars showed better elongation responses than taller ones and a few taller cultivars showed reduced culm length. The internode length of 1st, 5th, 6th and 7th were increased, but, 2nd, 3rd and 4th internodes were reduced. Especially the reduction of 3rd internode elongation and the increase of 5th internode length was prominent. Most of the tested cultivars showed no changes in the number of internodes elongated, but, in some cultivars it was increased and in a few ones it was reduced. The effect on the panicle length was variable depending cultivars. No significant correlation was found between the culm length elongation and the elongation of panicle length, implying that the response of GA$_3$ on the culm and on the panicle is independent of each other. According the response of culm length elongation tested cultivars were grouped into 6 ; Significantly reducing, slightly reducing, less sensitive, slightly elongating, largely elongating and extremely elongating.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.318-332
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• 2000

The purpose of this study was to investigate the effects of demineralized freeze-dried bone (DFDB) on mechanically exposed pulp of dog by evaluating the pulpal inflammation and healing process, formation of dental hard tissue, and structural changes of fibroblasts of the remaining pulp tissue. Teeth of 4 dogs, weighing 10kg, were used in this study. Class V cavities were prepared followed by exposed the pulp tissue mechanically by sterilized round bur. In control group, exposed pulps were capped with calcium hydroxide paste followed by sealed with IRM. In experimental groups, the exposed pulps of one group were capped with the collagen and those of the other group were capped with DFDB. All cavities were sealed with same manor as control group. The animals were sacrificed at the intervals of 3, 7, 14, and 28 days for histopathlogic evaluation. The specimens were observed by the light microscope and trans-electron microscope. The results were as follows: 1. Pulp necrosis was not observed in all groups. Inflammatory response was disappeared from 1 week in control group and group 2. But it was not disappeared until 2 weeks and also irregular arrangement of odontoblasts was showed at the lateral walls of root canal just beneath the amputated site of the pulp in group 1. 2. Dentinal bridge was formed incompletely at 2 weeks but it was formed completely at 4 weeks in control group. Odontoid tissue was also found in control group at 4 weeks from treatment. Amputated site of pulp was encapsulated with fibrous tissue and odontoblast and dentinal bridge was not found in group 1. Preodontoid tissue and reparative dentin which were formed by odontoblast differentiated around DFDB were found, but dentinal bridge was not found in group 2. 3. Cell with large basophillic-stained nuclei infiltrated to amputated site and DFDB at 1 week from treatment in control group and group 2. They were found more in group 2 than in control group. Odontoblasts arranged more regularly and reparative dentin was found more as time elapsed. 4. Dentin-formative odontoblasts which showed ultramicrostructure of cytoplasm with polarized nucleus, rEM, Golgi complex, secretory granules, secretion of organic matrix in control of group and group 2. In regards to above results, the demineralized freeze-dried bone(DFDB) induce odontoblastic differentiation and further come up to the dentin formation in amputated pulp.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.4
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• pp.273-278
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• 2022

This study evaluates the improved effect of photodynamic therapy (PDT) by subjecting pathogenic bacteria to a combination of 630 nm light-emitting diode (LED) and 5-aminolevulinic acid (ALA). Bacterial suspensions of 1.5×10⁴ cells/mL were diluted and exposed to ALA concentrations of 10, 5, 2.5, 1.25, and 0.625 mg/mL, incubated for 30 minutes, followed by irradiation with 630 nm LED (18 J/cm² ). The non-irradiated P. aeruginosa group and the group administered only LED light averaged 415 and 245 colonies, respectively. Conversely, the PDT group showed an average of 109, 225, 297, and 285 colonies at concentrations of 10, 5, 2.5, and 1.25 mg/mL of ALA. Evaluating the effect on E. faecalis revealed an average of 8,750 and 8,000 colonies in the group that did not receive the control photosensitizer and the group exposed to light alone, respectively. However, an average of 0, 2350, 4825, and 7475 colonies at concentrations of 5, 2.5, 1.25, and 0.625 mg/mL ALA were determined for the PDT groups. In conclusion, better inhibitory effects were observed for E. faecalis than for P. aeruginosa. Moreover, our results validate the possibility of improved PDT efficacy using a combination of ALA and 630 nm LED.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.177-185
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• 1997

Twenty-four major ecological and physiolosical characters of the 54 accessions of taro(Colocasia antiquorum) were observed in the growing seasons of 1995 and 1996 in $Ch{\breve{o}}nju$, Korea. The average days to emergence of the 54 accessions were 21.7 and the accession which had the shortest days to emergence was Kurye #2. Petiole color of most accessions was green, except $Ich{\breve{o}}n$ #1, Iri #1, Puan #1 and Taiwan #1 which had purple petioles. All the accessions had cormels except Taiwan #1 which had long runners without cormels. Average yield of the accessions was 3,719 kg/10a and total carmel weight, average carmel number, average carmel and average corm weight were 787g/plant, 39.2/plant, 20.3g/cormel, and 263.6g/plant, respectively. Accessions $Ch{\breve{o}}ngju$ #1 and Wanju #1 showed superiority in the three important characters, total carmel weight/plant, average carmel weight, and corm weight. Multivariate analysis for the 24 characters indicated that petiole color and carmel type had relatively higher coefficient of variation, 56.8 and 44.4 %, respectively. Fifty four taro accessions could be classified into 11 groups with D(${\sqrt{D^{2}}$) value of 110 on the basis of phenotypical characteristics. Most accessions were inclued in Group II. The Group I in which Taiwan #1 was included was genetically the most distant from the other groups. Accessions with purple petioles were grouped into the three different subgroups in which green petiole accessions were not included, indicating high dissimilarity between the different petiole color accessions. All the accessions grouped into the Group VIII, $Ch{\breve{o}}ngju$ #1, Wanju #1, Wanju #3, and $Taech{\breve{o}}n$ #2, had higher bioogical yield. Some accessions collected from the same district showed a high dissimilarity by being classified into the different subgroups.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.636-644
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• 1999

Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. The mechanisms of TNF cytotoxicity are not clearly understood and some has reported that reactive oxygen species(ROS) might be associated with them, but there is controversy about antioxidant effect on TNF cytotoxicity. This study was designed to compare the TNF cytotoxicity after antioxidant pretreatment with that of control to evaluate the role of ROS in the mechanism of TNF cytotoxicity. Method : We compared the TNF cytotoxicies to WEHI164(murine fibrosarcoma cell line) and ME180(human cervix cancer cell line) after antioxidant pretreatment with those of control by MIT(dimethylthiazolyl-diphenyltetrazolium bromide) assay. Results : In the control group, the TNF cytotoxicities were $92.2{\pm}2.8%$(WEHI164) and $59.9{\pm}7.0%$(MEl80). In the TMTU(tetramethyl thiourea) pretreatment group, those were $91.4{\pm}3.7%$ and $74.6{\pm}7.0%$. In the PMZ(promethazine) pretreatment group, those were $90.2{\pm}2.5%$ and $62.5{\pm}5.7%$. In the BHT(butylated hydroxytoluene) pretreatment group, those were $93.2{\pm}1.3%$ and $66.3{\pm}6.1%$. So there was no reduction in TNF cytotoxicity after antioxidants pretreatment. Conclusion : The ROS may not have major role in the mechanisms of TNF cytotoxicity.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.201-209
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• 2004

Extracorporeal life support (ECLS) system is a device for respiratory and/or heart failure treatment, and there have been many trials for development and clinical application in the world. Currently, a non-pulsatile blood pump is a standard for ECLS system. Although a pulsatile blood pump is advantageous in physiologic aspects, high pressure generated in the circuits and resultant blood cell trauma remain major concerns which make one reluctant to use a pulsatile blood pump in artificial lung circuits containing a membrane oxygenator. The study was designed to evaluate the hypothesis that placement of a pressure-relieving compliance chamber between a pulsatile pump and a membrane oxygenator might reduce the above mentioned side effects while providing physiologic pulsatile blood flow. The study was performed in a canine model of oleic acid induced acute lung injury (N=16). The animals were divided into three groups according to the type of pump used and the presence of the compliance chamber, In group 1, a non-pulsatile centrifugal pump was used as a control (n=6). In group 2 (n=4), a single-pulsatile pump was used. In group 3 (n=6), a single-pulsatile pump equipped with a compliance chamber was used. The experimental model was a partial bypass between the right atrium and the aorta at a pump flow of 1.8∼2 L/min for 2 hours. The observed parameters were focused on hemodynamic changes, intra-circuit pressure, laboratory studies for blood profile, and the effect on blood cell trauma. In hemodynamics, the pulsatile group II & III generated higher arterial pulse pressure (47$\pm$ 10 and 41 $\pm$ 9 mmHg) than the nonpulsatile group 1 (17 $\pm$ 7 mmHg, p<0.001). The intra-circuit pressure at membrane oxygenator were 222 $\pm$ 8 mmHg in group 1, 739 $\pm$ 35 mmHg in group 2, and 470 $\pm$ 17 mmHg in group 3 (p<0.001). At 2 hour bypass, arterial oxygen partial pressures were significantly higher in the pulsatile group 2 & 3 than in the non-pulsatile group 1 (77 $\pm$ 41 mmHg in group 1, 96 $\pm$ 48 mmHg in group 2, and 97 $\pm$ 25 mmHg in group 3: p<0.05). The levels of plasma free hemoglobin which was an indicator of blood cell trauma were lowest in group 1, highest in group 2, and significantly decreased in group 3 (55.7 $\pm$ 43.3, 162.8 $\pm$ 113.6, 82.5 $\pm$ 25.1 mg%, respectively; p<0.05). Other laboratory findings for blood profile were not different. The above results imply that the pulsatile blood pump is beneficial in oxygenation while deleterious in the aspects to high pressure generation in the circuits and blood cell trauma. However, when a pressure-relieving compliance chamber is applied between the pulsatile pump and a membrane oxygenator, it can significantly reduce the high circuit pressure and result in low blood cell trauma.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.165-174
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• 1998

The turnover of collagen is controlled by the balance between collagen synthesis and degradation. The production of collagenase (matrix metalloproteinase-1) and its inhibitor, tissue inhibitor of matrix metallopmteinase-1 (TIMP-1) are one of the substances which regulate this balance. The periodontal ligament fibroblast plays an important role in collagen metabolism during orthodontic treatment and is believed to be an origin of the osteoblast in the alveolar bone. The collagenase secreted by the periodontal ligament fibroblast and the osteoblast initiates the bone resorption by removing the osteoid layer in the alveloar bone. The interleukin-$1{\beta}$ is secreted by the macrophage during orthodontic treatment. The present study was undertaken to assess the effect of mechanical stress and interleukin-$1{\beta}$ on the expression of collagenase and TIMP-1 in the periodontal ligament fibroblasts using reverse transcription polymerase chain reaction and immunohistochemical staining. The periodontal ligament fibroblasts were stitched by placing the $Petriperm dish^{\circledR}$ dish on the top of spheroidal convex watch glass ($5\%$ surface increase) and tented with interleukin-$1{\beta}$ (1.0 ng/ml), or treated with both of them. Treatment with mechanical stress and/or interleukin-$1{\beta}$ resulted in increased collagenase mRNA expression. The mechanical stress treated group (1.61, 1.62, 1.37 fold increase), the interleukin-$1{\beta}$, tented group (1.68, 1.60, 3.78 fold increase), the mechanical stress and interleukin-$1{\beta}$ treated group (1.89, 1.72, 5.48 fold increase) induced increases in collagenase mRNA compared with the control group after 2, 4, 8 hours respectively. But TIMP-1 mRNA expressions at experimental groups were decreased after 2, 4 hours and increased after 8 hours. The mechanical stress treated group (0.16, 0.49 fold decrease and 3.77 fold increase), the interleukin-$1{\beta}$ treated group (0.15,0.44 fold decrease and 4.46 fold increase), the mechanical stress and interleukin-$1{\beta}$ tented group (0.15, 0.69 fold decrease and 4.81 fold increase) induced changes in TIMP-1 mRNA compared with the control group after 2, 4, 8 hours, respectively. Immunohistochemical stain showed that increased collagenase and TIMP-1 staining of the mechanical stress tented group, the interleukin-$1{\beta}$ treated group, and the mechanical stress and interleukin-$1{\beta}$ treated group compared with that of the control group after 8 hours. These findings suggest that mechanical stress and interleukin-$1{\beta}$ regulate expression of collagenase and TIMP-1.

• The Safety technology
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• no.203
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• pp.21-23
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• 2014

지난 1984년 개통된 88올림픽 고속도로는 '전라남도 담양군'과 '대구시 달성군'을 연결하는 고속도로로 동서교류를 확대하는 큰 역할을 하고 있다. 하지만 현재는 국내에서 유일한 왕복 2차선 고속도로인 것은 물론 중앙분리대가 없는 유일한 고속도로로 유명하다. 즉 늘어나는 교통량을 감당하지 못하고, 안전성에도 문제가 있는 것이다. 때문에 현재 88올림픽 고속도로가 포함된 제12호선 고속국도에서는 왕복 4차선으로의 확장공사가 한창 진행 중이다. 오늘의 주인공인 (주)포스코건설은 고속국도 제12호선의 담양~성산 간 확장공사 제3공구 현장을 책임지고 있다. 확장공사가 이뤄지는 목적이 고속도로 운전자들의 안전성 제고에 있는 만큼 이곳에서는 그 취지가 무색해지지 않게 근로자들의 안전을 최우선 가치로 여기고 있다. 이곳 현장에서 어떤 안전활동이 전개되고 있는 지 찾아가 봤다.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.29-34
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• 1993

Experiments have been carried out with C3H mouse fibrosarcoma (FSa II) to determine the effect of different sequence and time intervals between irradiation and administration of cis-diammihedichloroplatinum (cis-DDP) with gross tumors (6 mm in diameter), microscopic tumors (3 days after transplantation of $10^3$ cells) and cells in culture. The drug was administered either 24, 12, 8, 4, 2, 1, 0.5 hour before irradiation, immediately before irradiation, or 0.5, 1, 2, 4, 8, 12, 24 hours after irradiation. In case of in vivo studies, tumor growth delay was used as an end point. Clonogenic cell surviving fraction was used for in vitro studies. Tumor growth delay for gross tumor after 10 Gy radiation plus 10 mg/kg cis-DDP ranged from 6.3 to 10.66 days and the enhancement ratio ranged from 1.37 to 2.23. The most effective combination was when cis-DDP was given 4 hours before irradiation. Tumor growth delay for microscopic tumor after 5 Gy of radiation and 5 mg/kg of cis-DDP ranged from 3.55 to 11.98 days with enhancement ratio from 2.05 to 6.92. Microscopic tumors showed response significantly greater than additive in every time interval and the most effective treatments were when cis-DDP was given 2 and 1 hour before irradiation. In in vitro experiment, the surviving fraction after 6 Gy of radiation and 1 hour exposure to 4 ${\mu}M$ cis-DDP fluctuated as a function of time between treatments, but the difference between maximum and minimum surviving fractions was very small. According to the above results the sequence and time interval between irradiation and chemotherapy is very critical especially for the management of microscopic tumors as in the case of postoperative adjuvant treatment.

• Journal of Elementary Mathematics Education in Korea
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• v.13 no.2
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• pp.247-268
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• 2009

The purpose of this study was to examine the mathematical components of word problems and the structure of the components, to examine the characteristics of the understanding of mathematics high achievers about word problems, and ultimately to devise a teaching method geared toward facilitating learner understanding of the word problems. Given the findings of the study, the following conclusion was reached: First, word problems could be categorized according to their mathematical components, namely the mathematical structure of multiple variables provided to learners for their problem solving. And learner's reaction might hinge on the type of word problems. Second, the mathematics high achievers relied on diverse strategies to understand the mathematical components of word problems to solve the problems. The use of diverse strategies made it possible for them to succeed in problem solving. Third, identifying the characteristics of the understanding of the mathematics high achievers about word problems made it possible to layout successful lesson plans that stressed understanding of the mathematical structure of word problems. And the teaching plans enabled the learners to get a better understanding of the given word problems.