• Journal of Korean Neurosurgical Society
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• 제62권2호
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• pp.153-165
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• 2019

Objective : Spinal cord injury (SCI) is a very serious health problem, usually caused by a trauma and accompanied by elevated levels of inflammation indicators. Stem cell-based therapy is promising some valuable strategies for its functional recovery. Nestin-positive progenitor and/or stem cells (SC) isolated from pancreatic islets (PI) show mesenchymal stem cell (MSC) characteristics. For this reason, we aimed to analyze the effects of rat pancreatic islet derived stem cell (rPI-SC) delivery on functional recovery, as well as the levels of inflammation factors following SCI. Methods : rPI-SCs were isolated, cultured and their MSC characteristics were determined through flow cytometry and immunofluorescence analysis. The experimental rat population was divided into three groups : 1) laminectomy & trauma, 2) laminectomy & trauma & phosphate-buffered saline (PBS), and 3) laminectomy+trauma+SCs. Green fluorescent protein (GFP) labelled rPI-SCs were transplanted into the injured rat spinal cord. Their motilities were evaluated with Basso, Beattie and Bresnahan (BBB) Score. After 4-weeks, spinal cord sections were analyzed for GFP labeled SCs and stained for vimentin, $S100{\beta}$, brain derived neurotrophic factor (BDNF), 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase), vascular endothelial growth factor (VEGF) and proinflammatory (interleukin [IL]-6, transforming growth factor $[TGF]-{\beta}$, macrophage inflammatory protein [MIP]-2, myeloperoxidase [MPO]) and anti-inflammatory (IL-1 receptor antagonis) factors. Results : rPI-SCs were revealed to display MSC characteristics and express neural and glial cell markers including BDNF, glial fibrillary acidic protein (GFAP), fibronectin, microtubule associated protein-2a,b (MAP2a,b), ${\beta}3$-tubulin and nestin as well as anti-inflammatory prostaglandin E2 receptor, EP3. The BBB scores showed significant motor recovery in group 3. GFP-labelled cells were localized on the injury site. In addition, decreased proinflammatory factor levels and increased intensity of anti-inflammatory factors were determined. Conclusion : Transplantation of PI-SCs might be an effective strategy to improve functional recovery following spinal cord trauma.

• 대한의생명과학회지
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• 제24권4호
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• pp.372-379
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• 2018

Korean society is experiencing rapid growth due to industrialization and urbanization, and the aging of population is emerging. Degradation of the masticatory muscle due to aging and reduction of the number of mastications causes dry mouth syndrome with decreased saliva in the elderly. Changes in the amount and composition of saliva cause various oral diseases, especially, periodontal disease is closely related to the microorganisms that form the plaque. In the elderly education, stimulation saliva was collected at the first visit and the last visit to observe changes in microorganisms in the oral cavity. For the collection of the probes, the paraffin wax was chewed for 5 minutes. The samples were immediately refrigerated in a 50 cc plastic tube and then stored at $-20^{\circ}C$ until the next use. The subjects of this study were the elderly people aged 65 years or older, and the study was conducted on 16 persons, 3 males and 13 females. The distribution of saliva microorganisms according to rolling brushing method showed significant difference in all three groups (Aa & Red complex, Orange complex and Green complex) before and after the education. In the group who answered that they had dentures, it was confirmed that the amount of microorganisms before and after education was significantly reduced in all three groups. There was a significant decrease in the amount of microorganisms in the Aa & Red complex and Orange complex group in the case of hypertension related to systemic disease. In conclusion, the higher the interest of oral health and general health of the subjects, the more effective the education.

• 한국습지학회지
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• 제21권2호
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• pp.157-162
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• 2019

최근 세계적인 기상이변으로 이례적인 대설과 한파의 발생 빈도가 증가하고 있다. 이로 인해 대설피해 저감에 대한 연구가 진행되고 있으나, 우리나라는 시군구 별 과거 피해이력이 적고, 피해 발생지역과 관측소 간의 거리가 멀어 정확한 피해예측이 어려운 상황이다. 따라서 본 연구에서는 대설피해에 영향을 미친다고 생각되는 인자들의 데이터를 수집한 뒤 랜덤포레스트 모형의 설명변수로 설정하여 추정되는 대설피해액을 범주형태로 예측하고자 하였다. 또한 설명변수 중 취약성 분석을 통해 도출된 취약성 지수를 설명변수로 이용함으로써 지역적 특색과 특성을 반영하였다. 지금은 과거 피해 자료의 부족, 비닐하우스 설계 기준의 변화 등으로 인해 예측 정확도가 높지 않지만, 피해가 발생한 지역의 정확한 기상자료가 확보되고, 변수로 사용한 데이터의 업데이트가 진행된다면 본 연구 결과의 정확도 향상과 재난 발생 전 피해규모 및 범위에 대한 신속한 예측을 통해 대비차원의 재난관리 대처능력이 향상될 것으로 기대된다.

• 한국환경복원기술학회지
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• 제21권6호
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• pp.1-13
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• 2018

Mapping radiation heat flux of urban area is essential for urban design and landscape planning. Because controlling urban geometry and generating green space are important urban design strategies for reducing urban heat, urban planner and designer need to recognize the micro urban heat distribution for adequate urban planning. This study suggests a new methodology for mapping urban radiation heat flux in a micro scale considering buildings and trees' shade. For doing that, firstly, we calculate net radiation for each urban surfaces (building, road (not shaded, building shaded, tree shaded), ground (not shaded, building shaded, tree shaded), tree (not shaded, building shaded)). Then, by multiplying the area ratio of surfaces to the net radiation, we can obtain the radiation heat flux in micro-scale. The estimated net radiation results were found to be robust with a $R^2$ of 90%, which indicates a strong explanatory power of the model. The radiation heat flux map for 12h $17^{th}$ August explains that areas under the building and tree have lower net radiation heat flux, indicating that shading is a good strategy for reducing incident radiation. This method can be used for developing thermal friendly urban plan.

• 대한건축학회논문집:계획계
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• 제35권6호
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• pp.27-37
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• 2019

This study focused on the possibility of reducing the cooling load through the change of micro climate in the outdoor space during summer season. This study proposes an efficient planning model by comparing the effects of urban heat island mitigation through wind path planning, outdoor space vegetation, and exterior material change by using the basic model of the street-oriented block housing proposed in the previous research by the same author. As a result, the most effective wind path planning strategy in the street-oriented block housing was the change of the air flow through the mass height adjustment. When the tall building masses were staggered and arranged in a balanced manner, the overall wind environment could be improved. The greater the height difference between low and high masses, the better the air flow was shown. It was also important to arrange the building masses so that the inlet of the main wind was open and to allow the external space to connect to the adjacent block to create a continuous flow. The change of outdoor space vegetation and flooring, and the formation of wind paths through the opening of lower part also showed the effect of heat island reduction. In addition, the change of PMV in summer was the biggest influence of shadow by tall building mass. Attention should be paid to the fact that high-albedo exterior materials are adversely affected by multiple reflections in dense street-oriented block housing. The use of albedo of the exterior material showed that it is necessary to pay attention to apply in the high density block housing. This is attributed to the rise of the temperature due to the absorption of energy into the low-albedo flooring, where the high-albedo exterior causes multiple reflections.

• 교육녹색환경연구
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• 제20권1호
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• pp.19-28
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• 2021

국토교통부는 신(新)기후체제 출범에 따라 건물부분의 에너지절약 및 국가 온실가스 감축목표 달성을 앞당기기 위해 제로에너지건축물 인증제를 시행하고 있다. 2014년 ZEB 조기활성화 방안을 발표 하였으며, 2016년 1월 "녹색건축물 조성 지원법"을 개정하고 제도적 기반을 마련하여 2020년부터 공공부문을 시작으로 2025년 까지 민간부문 까지 단계적 제로에너건축물을 확산시키기 위한 계획을 수립 시행중에 있다. 2020년부터 공공부분에 속하는 학교시설은 제로에너지건축물 의무대상에 포함됨에 따라 본 연구에서는 학교시설 제로에너지건축물 인증시행에 따른 에너지요소별 자립률을 분석하고자 한다.

• 한국분말재료학회지
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• 제28권3호
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• pp.216-220
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• 2021

The effect of tert-butyl alcohol (TBA) as a freezing solvent on the pore structure of a porous tungsten body prepared by freeze-drying is analyzed. TBA slurries with a WO3 content of 10 vol% are prepared by mixing with a small amount of dispersant and binder at 30℃. The slurries are frozen at -25℃, and pores are formed in the frozen specimens by the sublimation of TBA during drying in air. After hydrogen reduction at 800℃ and sintering at 1000℃, the green body of WO₃ is completely converted to porous W with various pore structures. Directional pores from the center of the specimen to the outside are observed in the sintered bodies because of the columnar growth of TBA. A decrease in pore directionality and porosity is observed in the specimens prepared by long-duration drying and sintering. The change in pore structure is explained by the growth of the freezing solvent and densification.

• 한국분말재료학회지
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• 제28권4호
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• pp.331-335
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• 2021

The effects of drying temperature on the microstructure of porous W fabricated by the freeze-casting process of tert-butyl alcohol slurry with WO₃ powder was investigated. Green bodies were hydrogen-reduced at 800℃ for 1 h and sintered at 1000℃ for 6 h. X-ray diffraction analysis revealed that WO₃ powders were completely converted to W without any reaction phases by hydrogen reduction. The sintered body showed pores aligned in the direction of tert-butyl alcohol growth, and the porosity and pore size decreased as the amount of WO₃ increased from 5 to 10vol%. As the drying temperature of the frozen body increased from -25℃ to -10℃, the pore size and thickness of the struts increased. The change in microstructural characteristics based on the amount of powder added and the drying temperature was explained by the growth behavior of the freezing agent and the degree of rearrangement of the solid powder during the solidification of the slurry.

• Journal of Microbiology and Biotechnology
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• 제31권12호
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• pp.1656-1666
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• 2021

Dental pathogens lead to chronic diseases like periodontitis, which causes loss of teeth. Here, we examined the plausible antibacterial efficacy of copper nanoparticles (CuNPs) synthesized using Cupressus macrocarpa extract (CME) against periodontitis-causing bacteria. The antimicrobial properties of CME-CuNPs were then assessed against oral microbes (M. luteus. B. subtilis, P. aerioginosa) that cause periodontal disease and were identified using morphological/ biochemical analysis, and 16S-rRNA techniques. The CME-CuNPs were characterized, and accordingly, the peak found at 577 nm using UV-Vis spectrometer showed the formation of stable CME-CuNPs. Also, the results revealed the formation of spherical and oblong monodispersed CME-CuNPs with sizes ranged from 11.3 to 22.4 nm. The FTIR analysis suggested that the CME contains reducing agents that consequently had a role in Cu reduction and CME-CuNP formation. Furthermore, the CME-CuNPs exhibited potent antimicrobial efficacy against different isolates which was superior to the reported values in literature. The antibacterial efficacy of CME-CuNPs on oral bacteria was compared to the synergistic solution of clindamycin with CME-CuNPs. The solution exhibited a superior capacity to prevent bacterial growth. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and fractional inhibitory concentration (FIC) of CME-CuNPs with clindamycin recorded against the selected periodontal disease-causing microorganisms were observed between the range of 2.6-3.6 ㎍/ml, 4-5 ㎍/ml and 0.312-0.5, respectively. Finally, the synergistic antimicrobial efficacy exhibited by CME-CuNPs with clindamycin against the tested strains could be useful for the future development of more effective treatments to control dental diseases.

• Journal of Ginseng Research
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• 제46권4호
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• pp.505-514
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• 2022

Background: The roots of Panax ginseng contain two types of tetracyclic triterpenoid saponins, namely, protopanaxadiol (PPD)-type saponins and protopanaxatiol (PPT)-type saponins. In P. ginseng, the protopanaxadiol 6-hydroxylase (PPT synthase) enzyme catalyses protopanaxatriol (PPT) production from protopanaxadiol (PPD). In this study, we constructed homozygous mutant lines of ginseng by CRISPR/Cas9-mediated mutagenesis of the PPT synthase gene and obtained the mutant ginseng root lines having complete depletion of the PPT-type ginsenosides. Methods: Two sgRNAs (single guide RNAs) were designed for target mutations in the exon sequences of the two PPT synthase genes (both PPTa and PPTg sequences) with the CRISPR/Cas9 system. Transgenic ginseng roots were generated through Agrobacterium-mediated transformation. The mutant lines were screened by ginsenoside analysis and DNA sequencing. Result: Ginsenoside analysis revealed the complete depletion of PPT-type ginsenosides in three putative mutant lines (Cr4, Cr7, and Cr14). The reduction of PPT-type ginsenosides in mutant lines led to increased accumulation of PPD-type ginsenosides. The gene editing in the selected mutant lines was confirmed by targeted deep sequencing. Conclusion: We have established the genome editing protocol by CRISPR/Cas9 system in P. ginseng and demonstrated the mutated roots producing only PPD-type ginsenosides by depleting PPT-type ginsenosides. Because the pharmacological activity of PPD-group ginsenosides is significantly different from that of PPT-group ginsenosides, the new type of ginseng mutant producing only PPD-group ginsenosides may have new pharmacological characteristics compared to wild-type ginseng. This is the first report to generate target-induced mutations for the modification of saponin biosynthesis in Panax species using CRISPR-Cas9 system.