• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.72-72
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• 2000

ITO(Indium-Tin-Oxide)는 n-type 전도 특성을 갖는 산화물 반도체로서 가시광 영역에서의 높은 광투과율 및 낮은 전기 비저항을 나타내기 때문에 태양전지, 액정디스플레이(liquid crystal display), 터치스크린(touch screen) 등의 투명전극 재료, 전계 발광(electroluminescent) 소자, 표면발열체, 열반사 재료 등 다양한 분야에 응용되고 있다. 본 연구에서는 타겟 제작에 드는 비용을 줄이고, 타겟 이용의 효율성을 높이기 위해 기존의 세라믹 타겟 대신 분말 타겟을 사용하여 유리 기판 상에 ITO 박막을 DC magnetron sputtering법에 의해 제조하고, 열처리 온도 및 열처리 분위기에 따른 ITO 박막의 전기적 광학적 특성을 조사하였다. 열처리 온도가 10$0^{\circ}C$이하인 경우 열처리하지 않은 시편과 동일하게 In2O3의 (411)면에 해당하는 peak가 관찰되었다. 그러나 20$0^{\circ}C$의 온도로 열처리 할 경우 (411)면 peak의 세기는 상대적으로 감소하고 대신 이전에 나타나지 않았던 (222)면에 대응하는 peak 세기가 현저하게 증가함을 알 수 잇다. 이것은 ITO 박막의 경정성장이 열처리 전 (411)면 방향으로 이루어지나 20$0^{\circ}C$의 온도로 열처리 후 재결정화에 의해 (222)면 방향으로의 우선방위를 갖고 성장함을 의미한다. 또한 주로 높은 기판온도에서 관찰되었던 (211), (400), (411), (440), (622)면 등에 해당하는 peak가 나타남을 볼 수 있었다. 열처리 온도를 더욱 증가시킴에 따라 결정구조에는 큰 변화 없이 (222)면 peak 세기가 증가하였다. 한편 열처리 온도를 더욱 증가시킴에 따라 (222)면 peak 세기가 상대적으로 조금 감소할뿐 XRD회절 결과에는 큰 변화를 관찰할 수 없었다. 이러한 결과로부터 기판을 가열하지 않고 증착한 ITO 박막의 재결정화에 필요한 최소의 열처리 온도는 20$0^{\circ}C$이며, 그 이상의 열처리 온도는 ITO박막의 결정구조에 큰 영향을 미치지 않음을 알 수 있었다. 열처리 전 비저항은 1.1$\times$10-1 $\Omega$-cm 의 값을 가지거나 10$0^{\circ}C$의 온도로 열처리함에 따라 9.8$\times$102$\Omega$-cm 로 약간 감소하였다. 열처리 온도를 20$0^{\circ}C$로 높임에 따라 비저항은 급격히 감소하여 1.7$\times$10-3$\Omega$-cm의 최소값을 나타내었다. 열처리 온도가 10$0^{\circ}C$인 경우 가시광 영역에서의 광투과율은 열처리하지 않은 시편과 비교해 볼 때 약간 증가하였다. 열처리 온도는 20$0^{\circ}C$로 증가시킴에 따라 투과율은 크게 향상되어 흡수단 이상의 파장영역에서 90% 이상의 투과율을 나타내었다. 이러한 광투과율의 향상은 앞서 증착된 ITO 박막이 열처리 중 재결합에 의해 우선 성장 방위가 (411)면 방향에서 (222)면 방향으로 변화되었기 때문으로 생각된다. 그러나 열처리 온도를 20$0^{\circ}C$이상으로 증가시켜도 광투과율은 큰 변화를 나타내지 않았다.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.37-40
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• 2002

Sweet potato is a crop vegetatively propagated by vine cuttings, an ineffective method for maintaining pathogene-free stock plants. As an alternative method, single-node cultures of virus-free plantlets derived from apical meristem in sweet potato (cv. Yulmi) was examined. Effective pH range, sugar concentration and nodal order were investigated to establish an in vitro mass propagation system with high quality virus-free stock plantlets to farmhouse. Although the plantlets grew at wide range of pH, the most effective pH of the medium was 4.8 in single-node cultures. High sugar concentration of 60∼80 g/L resulted in increased growth response in shoot length, root length, number of node, leaf area and fresh and dry weight of shoot and root, whereas reducing sugar contents below 6% was showed reduced growth response. The first node including meristem tip was the best for the rapid growth of plantlets and the other nodes also showed a very similar growth response. Uniform plantlet can be obtained massively at the same time by culture of single node except for the first node including meristem tip. In conclusion, the most effective pH range and sugar concentration of medium for the growth of plantlets via single-node cultures was 4.8, 60∼80 g/L respectively. The first node was the best for the rapid propagation of plantlets in nodal order.

• Journal of Convergence for Information Technology
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• v.11 no.8
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• pp.129-136
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• 2021

This study aims to verify the influence of married men in their 30s and 40s on smartphone addiction, the mediating effect of depression, and the moderating effect according to age. To this end, samples were set up as a convenient sampling for married men in their 30s and 40s living in the Seoul, Gyeonggi, Incheon metropolitan. To verify the influence relationship, mediating effect, and moderation effect of the main variables, we compare the differences in influence by dividing age groups through spss win 25 program Baron & Kenny's analysis, Sobel test, and multi-regression analysis. The analysis results are as follows. First, stress has a positive effect on depression and smartphone addiction, and depression has a positive effect on smartphone addiction. Second, depression has been shown to have a partial mediating effect in the relationship between stress and smartphone addiction. Third, there was a difference in influence between stress and smartphone addiction depending on age groups. Based on the above results, we present policy implications and follow-up research suggestions.

• Journal of Plant Biotechnology
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• v.46 no.1
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• pp.32-36
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• 2019

Calla lilies (Zantedeschia spp.) are monocotyledonous ornamental plants which belongs to the Araceae family. After the release of elite calla cultivar, an efficient propagation system is needed for commercial use. Despite the use of conventional propagation methods such as splitting of tubers and rhizomes of calla, rapid and efficient propagation system should be developed. In order to achieve this goal, stem segments contained apical meristems derived from calla lily cultivar (cv. Gag-si) were cultured on Murashige and Skoog (MS) medium supplemented with various concentrations of cytokinin and auxin. This was aimed at inducing embryogenic calluses, shoots and multiple shoots. As a result, about 25% of induction rates of yellow embryogenic calluses were observed with MS medium containing both $0.5mg{\cdot}L^{-1}\;NAA$ and $1.5mg{\cdot}L^{-1}\;BA$ as growth regulators. In the experiments involving the regeneration from embryogenic calluses through shoot formation, MS medium supplemented with $0.5mg{\cdot}L^{-1}\;IAA$ and $2.0mg{\cdot}L^{-1}\;BA$ showed the highest rates at approximately 85 ~ 90% with regard to the formation of shoots in calla. Moreover, multiple shoots needed for rapid propagation were generated when explants were cultured on MS medium supplemented with $0.5mg{\cdot}L^{-1}\;IAA$ and $2.0mg{\cdot}L^{-1}\;BA$ with 40% of formation rate. In this study, the combination of auxin and cytokinin showed positive effects on both the induction of embryogenic calluses, the formation of shoots as well as multiple shoots in calla. The regeneration system described here can contribute to the development of breeding programs of calla in the future.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.658-668
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• 2022

Purpose To evaluate the effectiveness of the transradial artery approach (TRA) for treating malfunctioning arteriovenous fistulas (AVFs) in patients on hemodialysis. Materials and Methods A retrospective analysis was conducted in this single-center study of TRA endovascular procedures in 73 patients (43 male and 30 female; mean age of 67.4 years (range, 42-92 years) with malfunctioning AVFs, between January 2008 and April 2019. Patients' baseline and lesion characteristics, technical and clinical success, and complications were evaluated, and functional patency was analyzed using the Kaplan-Meier method. Results Radial artery approaches were successful in all patients. Angioplasty performed using the TRA achieved technical and clinical success rates of 98.6%(72/73) and 91.7%(67/73), respectively. The median primary patency time was 18.8 ± 15.9 months. The primary functional patency rates at 3, 6, and 12 months were 82.1%, 68.6%, and 63.9%, respectively. There were no major complications or adverse events, such as hand ischemia, related to the radial artery approach. Conclusion In selected cases, the TRA can be used complementary to the transvenous approach to treat malfunctioning AVFs.

• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.153-171
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• 2018

This study focuses on the investigation of geologic distribution and stratigraphy in the eastern part of Yeongdeok-gun, based on Lidar imaging, detailed field survey, microscopic observations, SHRIMP and LA-MC-ICPMS U-Pb age dating, and a new geological map has been created. The stratigraphy of the study area is composed of the Paleoproterozoic metamorphic rocks consisting of banded gneisses of sedimentary origin and schists ($1841.5{\pm}9.6Ma$) of volcanic origin, Triassic Yeongdeok plutonic rocks ($249.1{\pm}2.3Ma$) and Pinkish granites ($242.4{\pm}2.4Ma$), Jurassic Changpo plutonic rocks ($193.2{\pm}1.9Ma{\sim}188.8{\pm}2.0Ma$) and Fine-grained granites ($192.9{\pm}1.7Ma$), Formations [Gyeongjeongdong Fm, Ullyeonsan Fm. (~108 Ma), Donghwachi Fm.] of the Early Cretaceous Gyeongsang Supergroup and acidic volcanic rocks and dykes erupted and intruded in the Late Cretaceous, Miocene intrusive rhyolitic tuffs ($23.1{\pm}0.2Ma{\sim}22.97{\pm}0.13Ma$) and sedimentary rocks of the Yeonghae basin, and the Quaternary sediments. The Triassic Pinkish granites, Jurassic Changpo plutonic rocks and Fine-grained granites are newly defined plutonic rocks in this study. Miocene intrusive rhyolitic tuffs bounded by the Yangsan Fault, which was first discovered in the north of Pohang city, are believed to play an important role in the understanding of the Miocene volcanic activity and the crustal deformation history on the Korean Peninsula. It is confirmed that The NNE-SSW-striking Yangsan Fault penetrating the central part of the study area and branch faults are predominant in the dextral movement and cutting all strata except the Quaternary sediments.

• Childhood Kidney Diseases
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• v.2 no.1
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• pp.60-68
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• 1998

Purpose: To determine the various prenatal factors related to the prenatal hydronephrosis diagnosed on prenatal ultrasonography. We also attempted to correlate the prenatal and neonatal renal pelvic anteroposterior diameter with the outcome in infancy Methods: Between 1985 and 1997. We retrospectively reviewed 105 renal unit (75 patient) with fetal hydronphrosis persisting postnatally. Investigation consisted of renal ultrasonography, voiding cystourethrography, diurectic renogram, and DMSA scan. Results: The 75 patient assesed had the following underlying cause: UPJ(Ureteropelvic juction) obstruction(52%). multicystic dysplastic kidney(10%). UVJ (Ureterovesicai juction) obstruction (10%) and no underlying cause (25%). Of theses cases 36 cases (40 renal unit) underwent operation, while 28 cases (50 renal unit) resoled spontaneously. 12% of mild hydornephrosis deteriorated. whereas 50% of modrate hydrophrosis and 81% of severe hydronephrosis required surgical correction. Attempting to find the renal unit that were at risk for deterioration. our study showed that urinary tract infection group and calyceal blunting group had a predictive role. Conclusion: It is necessary to follow up after birth dilatation of caylx or urinary tract infection are present. Early operation is considered when prenatal pelvic AP diameter greater is than 22 mm and postnatal diameter greater than 17 mm. This may make it possible to prevent further progression of renal damage and prompt treatment of asymptomatic hydronephrosis before complications occur.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.468-476
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• 2020

This study was performed to establish light intensity conditions for producing stem cuttings for aeroponic systems suitable for seed potato production using a closed-type plant production system. Shoot tip cultured plantlets of 'Sumi' and 'Chubaek' potato (Solanum tuberosum L.) were acclimatized, cuttings were collected, and stem cuttings were planted. The seedlings were raised for 40 days at different LED light intensities (60, 120, 180, and 240 μmol·m^-2·s^-1), and were cultivated in an aeroponic system for 80 days. When stem cuttings were raised at 60 μmol·m^-2·s^-1 LED light intensity, the plant height was the longest, at 17.3 cm for 'Sumi' and 16.1 cm for 'Chubaek', and the number of nodes was the highest in both cultivars. The higher light intensities, produced smaller plants with fewer nodes. The leaf areas, SPAD values, and Fv/Fm values differed slightly between cultivars. The fresh weight of stem cuttings, and the production rate of healthy stem cuttings were the highest at 60 μmol·m^-2·s^-1. In the aeroponic system, seedlings raised at 60 μmol·m^-2·s^-1 with LED light intensity showed a difference between the cultivars, but the fresh weight of stems and leaves above the planting plate was the heaviest. In addition, below the planting plate the stem cuttings were longest and the root weight was heaviest at 60 μmol·m^-2·s^-1 LED light intensity. The number of stolons also differed between cultivars, but was greatest for seedlings raised at 60 μmol·m^-2·s^-1 LED light intensity, at 4.2/plant for 'Sumi' and 7.7/plant for 'Chubaek'. At 60 μmol·m^-2·s^-1 LED light intensity, the tuber number and total tuber weight were the best, but the higher the light intensity, the smaller the total tuber number and total tuber weight for both cultivars. In conclusion, when producing potato stem cuttings for aeroponic systems using a closed-type plant production system, the most suitable LED light intensity for raising seedlings was found to be 60 μmol·m^-2·s^-1.

• Journal of Embryo Transfer
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• v.21 no.4
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• pp.315-322
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• 2006

This study was performed to investigate the physiological effects of bovine follicular fluid (bFF) or anti-inhibin serum (AI) on follicular development in Hanwoo. Saline (0.95%), bFF or AI (total of 40 ml) were administered into the jugular vein in 9 Hanwoo cows. The plasma inhibin, estradiol-17 $\beta$ (E2), and progesterone (P4) levels were measured using RIA or ELISA kit and the number of ovarian follicles was observed by ultrasonography at 72 hr after ovulation. The plasma inhibin level in bFF treatment group was significantly increased and maintained higher level from 102 hr after ovulation compared to that of saline and AI groups (p<0.05). In plasma E2 level, AI treatment group showed significantly higher level from 36 hr to 108 hr after ovulation than that of saline and bFF groups (p<0.05). After that it showed decreasing tendency. The plasma P4 level was increased in control and AI treatment groups at 68 hr after ovulation. However, it was maintained significantly lower level in bFF group from 84 hr to 180 hr compared to that of saline and AI group (p<0.05). As a result of ultrasonography at 72 hr after ovulation, higher number of follicles was shown in AI treatment group compared to bFF groups, although the difference was not statistically significant. Taken together, it can be postulated that a treatment of synthesized AI inhibits the secretion of inhibin, stimulates FSH secretion inhibited by inhibin, and induces follicular development and estrogen secretion. According to these results, a development of ovarian follicle immediately after ovulation is associated closely with inhibin in Hanwoo heifers.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.297-306
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• 2004

Current artificial heart valves have several disadvantages, such as thromboembolism, limited durability, infection, and inability to grow. The solution to these problems would be to develop a tissue-engineered heart valves containing autologous cells. The aim of this study was to optimize the protocol to obtain a porcine acellular matrix and seed goat autologous endothelial cells on it, and to evaluate the biological responses of xenograft and xeno-autograft heart valves in goats. Material and Method: Fresh porcine pulmonic valves were treated with one method among 3 representative decellularization protocols (Triton-X, freeze-thawing, and NaCl-SDS). Goat venous endothelial cells were isolated and seeded onto the acellularized xenograft leaflets. Microscopic examinations were done to select the most effective method of decellularizing xenogeneic cells and seeding autologous endothelial cells. Two pulmonic valve leaflets of. 6 goats were replaced by acellularized porcine leaflets with or without seeding autologous endothelial cells while on cardiopulmonary bypass. Goats were sacrificed electively at 6 hours, 1 day, 1 week, 1 month, 3 months, and 6. months after operation. Morphologic examinations were done to see the biological responses of replaced valve leaflets. Result: The microscopic examinations showed that porcine cells were almost completely removed in the leaflets treated with NaCl-SDS. The seeded endothelial cells were more evenly preserved in NaCl-SDS treatment. All 6 goats survived the operation without complications. The xeno- autografts and xenografts showed the appearance, the remodeling process, and the cellular functions of myofibroblasts, 1 day, 1 month, and 3 months after operation, respectively. They were compatible with the native pulmonary leaflet (control group) except for the increased cellularity at 6 months. The xenografts revealed the new endothelial cell lining at that time. Conclusion: Treatment with NaCl-SDS was most effective in obtaining decellularized xenografts and facilitate seeding autologous endothelial cells. The xenografts and xeno-autografts were repopulated with myofibroblasts and endothelial cells in situ serially. Both of grafts served as a matrix for a tissue engineered heart valve and developed into autologous tissue for 6 months.