• Journal of Periodontal and Implant Science
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• v.42 no.2
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• pp.50-58
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• 2012

Purpose: This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. Methods: A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral $4{\times}{\times}4{\times}5$ mm (buccolingual width${\times}$mesiodistal width${\times}$depth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. Results: Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. Conclusions: In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation.

• Restorative Dentistry and Endodontics
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• v.45 no.2
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• pp.4.1-4.6
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• 2020

Although numerous studies have been conducted on apexification using mineral trioxide aggregate (MTA), direct observation of extracted human teeth after the procedure has been rarely reported. This case report describes a mandibular premolar treated 2.5 years ago and extracted recently for orthodontic treatment. The tubercle of the right mandibular premolar of a 12-year-old boy with dens evaginatus was fractured and the pulp was exposed. The tooth was diagnosed with pulp necrosis and asymptomatic periapical abscess. During the first visit, copious irrigation was performed with 2.5% sodium hypochlorite. Calcium hydroxide paste was placed as an intracanal medicament. The sinus tract had disappeared at the second visit after 3 weeks. MTA was applied on to the bleeding point as a 4-mm-thick layer, followed by a 3-mm-thick gutta-percha filling and resin core build-up. After 2.5 years, the tooth and three other premolars were extracted for orthodontic treatment. The right and left mandibular premolars were scanned with micro-computed tomography to determine the root shape and canal anatomy. Irregular root growth was observed and the root outline of the right mandibular premolar differed from that of the contralateral tooth. Apexification with MTA leads to the formation of roots with irregular morphology, without any pulpal space.

• The Korean Journal of Pain
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• v.20 no.1
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• pp.54-59
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• 2007

Background: Selective transforaminal epidural block (STEB) has showen effectiveness as a diagnostic and therapeutic option for the management of patients with low back pain or sciatica. This study was carried out in order to determine the short-term effects and prognostic factors associated with STEB in patients with low back pain or sciatica. Methods: Ninety-seven patients were selectedfor participation in this study. Their diagnosis were based werewason the clinical symptoms and MRI findings. We performed STEB under fluoroscopic guidance and injected 3 ml of radio opaque dye in order to confirm the technical success of the procedure. We then injected 20 mg of triamcinolone mixed into 3 ml of 0.5% mepivacaine. One month later, we classified the patient outcomes as excellent, good, moderate or poor, according to the degree of reduction in VAS score from baseline. The independent variables assessed included symptom duration, block level, number of blocks, primary diagnosis, prior caudal block, anterior epidural space filling of dye, medication history, demographic data, radiating pain, back surgery and spondylolisthesis. Results: At a mean follow-up period of 1 month after STEB, excellent results were noted in the patients diagnosed with herniated lumbar disc (70%), non-specific spondylosis (54%), spinal stenosis (44%), and failed back syndrome (28%). The patients with epidural adhesion and combined spondylolisthesis were associated with poorer outcomes. Combined caudal block, symptom duration and the extent of epidural spread of the drug were not related to the effectiveness of the treatment. Conclusions: Selective transforaminal epidural block is effective in treating patients with radiculopathy, such as herniated lumbar disc, but it isrelatively ineffective in treating patients with structural deformities, such as failed back syndrome and spondylolisthesis.

• Journal of the Korean Geosynthetics Society
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• v.13 no.4
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• pp.45-56
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• 2014

Frozen ground in cold region consists of an upper active layer and lower permafrost which is permanently frozen land. During the summer season, the air temperature is high enough to make the frozen ground melt, which causes the reduction of soil strength and thaw settlement. These phenomena result in structural instability, so it is necessary to apply frozen ground stability techniques. Thermosyphon is a closed natural two-phase convection device to maintain the ground temperature below $0^{\circ}C$ by extracting heat from the ground and discharges it into the atmosphere. Experimental and numerical investigation has been performed to estimate the effect of the refrigerant filling ratio in thermosyphon using R-134a refrigerant and the thermal conductance of the thermosyphon.

• Bulletin of the Korean Chemical Society
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• v.2 no.2
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• pp.60-66
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• 1981

The hypothesis that three classes of water exist in hydrogels, namely X water (free water-like), Z-water (bound water-like), and Y water (interfacial water-like), has been verified and generally accepted. To further check the validity of this hypothesis and to study the nature of X, Y, and Z water as conformation changes, several experiments have been done using Tactic Poly(2-hydroxyethyl methacrylate) (P-HEMA) gels. Thermal expansively data for tactic P-HEMA gel was obtained. In each case of isotactic and syndiotactic P-HEMA, the higher water content gels showed an extremely sharp volume change at $0^{\circ}C$, indicating the presence of normal free water-like. Lower water content gels showed no anomalous change in thermal expansion, indicating that the water is bound water-like. The medium water content gels exhibited intermediate behavior. These results were also confirmed by bulk gel conductivity measurments. The differential scanning calorimeter(DSC) experiment was simply introduced to further verify the bound water-like quantities which was obtained by the method of dilatometry and specific conductivity. Observing the amounts of X, Y, and Z water with the change of tacticity, the similar content of bound water-like may be due to the same primary structure of isotactic and syndiotactic polymer and the difference in free and interfacial water-like content may be due to the difference in secondary and tertiary structure of tactic polymer. Therefore, as the polymer conformation varies, the free and interfacial water-like content will be varied. In order to demonstrate these concepts, Russel et al.'s CPK space-filling molecular models of isotactic and syndiotactic P-HEMA was utilized.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.95-103
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• 2021

I began to produce a series of works based upon the plastic element as a visual transmission -such as points, lines, sides, volumes and cubics, movements with in time, and space- which appeared in the optical art, that emerged in the 1950s and the early 1960. My works, which portray the natural scenes such as mountains, trees, and flowers that are commonly seen around us, are completed by drawing, erasing, filling with many points and overlapping. My works also ignore the scenography. All artistic activities must be based upon humanistic values and ultimately need to work for human being. The work with application of opt art did not use the perspective, but diverse colors. The work with application of opt art did not use the perspective, but diverse colors. The work tried to express more diverse impression rather than the emotion from the familiar perspective. We hope, therefore, my works give pleasure and satisfaction to these who come to see them.

• The Journal of the Acoustical Society of Korea
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• v.42 no.3
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• pp.181-188
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• 2023

In a typical living space, windows are directly exposed to the external noise environment. The best way to reduce outside noise is to block it from the outside, not the inside. Exterior blinds for blocking sunlight are commercialized in various ways. However, it has not yet been actively utilized in Korea. In the previous study, an experiment was conducted in an accredited laboratory to verify the sound insulation performance of an external motorized blind manufactured for shading. And it was verified that there is a sound insulation performance of 6 dBA compared to the reduction performance of a general window. In this study, we tried to confirm the reduction performance by applying the sound insulation performance of external electric blinds to windows in actual living spaces. In addition, an improvement plan was sought to increase the effective noise reduction performance. As a result of the measurement, the reduction performance of the external motorized blind itself was insufficient at the level of 1 dBA to 3 dBA. However, additional reduction performance of the 2 dBA level was confirmed by filling the gap between the blind slits.

• Korean Journal of Social Welfare Studies
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• v.41 no.4
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• pp.107-133
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• 2010

This research identified the normal structures of separated families, "wild-geese families"(husbands living in Korea apart from their wives and children who are studying abroad) as we called, in Korea. In particular, this study conducted in-depth interview, using qualitative research method, with 7 wild-geese fathers (fathers who are in order to understand their experiences of separated families. The research findings classified the wild-geese father's experiences into three phases which as "decision-making," "initial," and "maintenance." These phases can be described by five higher factors. First of all, in the phase of decision-making "internal or external needs of children studying abroad at early age" was found to be a crucial factor. Liberation and deficiency as results of separation" mainly described the initial phase. In the phase of maintenance, families experience "exhausted solitary lives," "filling up the families' empty space," and "double jeopardy-worry about both reunifying the family or separating the family, as the longer they are separated."

• Journal of Korean Academy of Nursing
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• v.53 no.5
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• pp.538-555
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• 2023

Purpose: This qualitative study used interpretative phenomenological analysis and photovoice methods to explore the meaning of non-suicidal self-injury experienced by adolescents. Methods: Participants were adolescents enrolled in middle and high schools in Gyeonggi-do and Jeollabuk-do who were selected through snowball sampling. Six participants had repeatedly engaged in self-injurious behavior for over a year. Data were collected through in-depth interviews and the photovoice method between November 2020 and July 2021. The collected data were analyzed using six steps of interpretative phenomenological analysis. Results: The results yielded 5 main themes and 18 subthemes. The main themes were 'a silent cry to an indifferent world', 'a heartache that one endures with scars', 'an inescapable cycle', 'filling the space in one's heart', and 'healing the wounds'. The study findings revealed that the self-injurious behavior of adolescents began as a consequence of feeling lost and struggling with conflicts at home and school, which helped them relieve tension and pain. Nonetheless, inflicting self-injury only left signs of regret and remorse, which became a trace that the participants wanted to hide. However, the wounds healed after receiving attention and support from others. They were determined to stop engaging in repeated self-injurious behaviors and made efforts to do so. Conclusion: This study can be used as a basis for the development of educational programs to prevent non-suicidal self-injury in adolescents. Additionally, it can inform nursing interventions that focus on building support systems to help adolescents who attempt self-injury.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.376-383
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• 2021

Objective: To assess the safety and efficacy of lymphopseudoaneurysm (LPA) glue (n-butyl cyanoacrylate [NBCA]) embolization in the management of chylous ascites after retroperitoneal surgery. Materials and Methods: A retrospective analysis from January 2014 to October 2018 was performed in six patients (4 females and 2 males; mean age, 45.3 ± 14.2 years; range, 26-61 years) who underwent LPA embolization for chylous ascites developing after retroperitoneal surgery involving the perirenal space (four donor nephrectomies, one partial nephrectomy, and one retroperitoneal lymphadenectomy). After placing a percutaneous drainage catheter into the LPA or adjacent lymphocele, embolization was performed by filling the LPA itself with a mixture of glue and Lipiodol (Guerbet). Results: Daily drainage from percutaneously placed drains exceeded 300 mL/day despite medical and surgical treatment (volume: mean, 1173 ± 1098 mL; range, 305-2800 mL). Intranodal lymphangiography was performed in four of the six patients and revealed leakage in 2 patients. Percutaneous embolization of the LPA was successful in all patients using an NBCA and Lipiodol mixture in a ratio of 1:1-1:2 (volume: mean, 4.3 ± 1.1 mL; range, 3-6 mL). Chylous ascites was resolved and the drainage catheter was removed in all patients within 4 days after the procedure (mean, 2.0 ± 1.8 days; range, 0-4 days). No procedure-related complications or recurrence of chylous ascites occurred during a mean follow-up period of 37.3 months (range, 21.1-48.4 months). Conclusion: Glue embolization of LPA has the potential to be a feasible and effective treatment method for the management of chylous ascites after retroperitoneal surgery.