• 한국화재소방학회논문지
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• 제30권5호
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• pp.100-107
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• 2016

오늘날 인간의 삶의 질 향상과 다양한 욕구를 충족시키기 위한 건축물은 대형화, 고층화, 다양화되는 추세이며, 이에 따른 화재의 발생빈도 및 잠재적인 위험요소가 증가되고 있다. 특히, 화재발생 시 수직으로의 연소확대 위험성이 증가되어 재실자의 피난시간이 지연되는 문제점이 있다. 이러한 문제점을 극복하기 위해서는 화재를 조기에 감지하고 건축물의 구조 등을 감안하여 위험순위에 따른 화재 경보방식을 적용할 필요가 있다. 따라서, 본 논문에서는 수직 연소확대의 위험성을 많이 내포하고 있는 2가지 구조인 전면형 이중외피 구조와 계단 구조에 대해 수직 연소확대 특성을 설명하고, 국내 외 화재경보방식을 비교 검토한 후 FDS 이용하여 연기밀도, 가시거리, CO 농도를 비교 분석하여 각 구조에 적합한 화재경보방식을 제안하였다.

• Bulletin of the Korean Chemical Society
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• 제12권5호
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• pp.554-559
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• 1991

The photophysical and photochemical properties of khellin were compared with those of 8-methoxypsoralen (8-MOP). Quantum yields of fluorescence and triplet formation decreases as solvent polarity increases, which is opposite to 8-MOP, and photocycloadditivity of khellin to olefins is much lower than that of 8-MOP. Electron ejection from khellin by laser flash was not observed, but observed from 8-MOP. As models of 4',5'-monoadducts of khellin or 8-MOP with thymine base, khellin<>dimethylfumarate 4',5'-monoadduct (KDF) was also compared with 8-MOP<>thymidine 4',5'-monoadduct (F-2) in those properties to give some insight on the second-step biadduct formation resulting in cross-links of DNA duplex. KDF and F-2 were very similar to khellin and 8-MOP in photophysical properties, respectively. However, KDF did not form adducts with various olefins, and thus it is thought that 2,3-double bond of chromone moiety in khellin is hardly reactive in contrast with 3,4-double bond of coumarin moiety in 8-MOP. These results indicate that khellin is fairly photostable compound, a poor type Ⅰ photodynamic sensitizer and producer of ${O_2}^{-}$ which is some cause of phototoxic erythemal reactions and undesirable side effects. Therefore khellin is safer to use than 8-MOP in photochemotherapy of some skin diseases. Although khellin is much less reactive than 8-MOP, khellin must be also a monofunctional drug. Since khellin is, however, as effective as 8-MOP in photochemotherapy of some skin diseases, it is suggested that khellin may be different from 8-MOP in the action mechanism.

• Journal of Ginseng Research
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• 제45권5호
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• pp.610-616
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• 2021

Background: Thymic stromal lymphopoietin (TSLP) acts as a master switch for inflammatory responses. Ginsenoside Rg3 (Rg3) which is an active ingredient of Panax ginseng Meyer (Araliaceae) is known to possess various therapeutic effects. However, a modulatory effect of Rg3 on TSLP expression in the inflammatory responses remains poorly understood. Methods: We investigated antiinflammatory effects of Rg3 on an in vitro model using HMC-1 cells stimulated by PMA plus calcium ionophore (PMACI), as well as an in vivo model using PMA-induced mouse ear edema. TSLP and vascular endothelial growth factor (VEGF) levels were detected using enzyme-linked immunosorbent assay or real-time PCR analysis. Murine double minute 2 (MDM2) and hypoxia-inducible factor 1α (HIF1α) expression levels were detected using Western blot analysis. Results: Rg3 treatment restrained the production and mRNA expression levels of TSLP and VEGF in activated HMC-1 cells. Rg3 down-regulated the MDM2 expression level increased by PMACI stimulation. The HIF1α expression level was also reduced by Rg3 in activated HMC-1 cells. In addition, Rg3-administered mice showed the decreased redness and ear thickness in PMA-irritated ear edema. Rg3 inhibited the TSLP and VEGF levels in the serum and ear tissue homogenate. Moreover, the MDM2 and HIF1α expression levels in the ear tissue homogenate were suppressed by Rg3. Conclusion: Taken together, the current study identifies new mechanistic evidence about MDM2/HIF1α pathway in the antiinflammatory effect of Rg3, providing a new effective therapeutic strategy for the treatment of skin inflammatory diseases.

• Steel and Composite Structures
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• 제31권1호
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• pp.1-12
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• 2019

Steel-concrete composite walls have been proposed and developed for applications in various types of structures. The double-skin profiled composite walls, as a natural development of composite flooring, provide structural and architectural merits. However, adequate intermediate fasteners between profiled steel plates and concrete core are required to fully mobilize the composite action and to improve the structural behavior of the wall. In this research, two new types of fasteners (i.e., threaded rods and vertical plates) were proposed and three specimens with different fastener types or fastener arrangements were tested under axial compression. The experimental results were evaluated in terms of failure modes, axial load versus axial displacement response, strength index, ductility index, and load-strain relationship. It was found that specimen with symmetrically arranged thread rods sustained more stable axial strain than that with staggered arranged threaded rods. Meanwhile, vertical plates are more suitable for practical use since they provide stronger confinement to profiled steel plate and effectively prevent the steel plate from early local buckling, which eventually enhance the composite action and increase the axial compressive capacity of the wall. The calculation methods were then proposed and good agreement was observed between the test results and the predicted results.

• Advances in Computational Design
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• 제7권4호
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• pp.321-343
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• 2022

Museum buildings display artefacts for public education and enjoyment, ensuring their long-term safety and the comfort of visitors by following strict indoor environment control protocols using mechanical Heating, Ventilation and Air Conditioning (HVAC) systems to keep the (environmental) variables at a fixed comfort level. Maintaining this requires constant supply of energy currently mostly sourced from the combustion of fossil fuels which exacerbates climate change. However, a review on the effects of the indoor environmental variables on museum artefacts as well as museum visitors revealed that there is no specific point at which artefact deterioration occurs, and that there are wide ranges of conditions that guarantee the long-term safety of artefacts and human comfort. Visits to museum buildings in hot-humid tropical climate of Nigeria revealed that strict indoor environmental practices were adopted. Even when appropriate micro-climatic conditions are provided for artefacts, mechanical HVAC systems remain necessary for visitor comfort because almost no consideration is given to natural ventilation. With the current global push towards energy management, this paper reviewed passive environmental control practices, architectural design strategies, and discusses the adaptation of double skin façade with jali screens, and the notion of smart materials, which can satisfy the range of requirements for the long-term safety of artefacts and levels of human comfort in buildings in hot-humid tropical climate, without mechanical HVAC systems. This review would inspire more discussions on passive, energy efficient, smart and climate responsible popular architecture, challenging current thinking on the impact of the more accepted representative architecture.

• Steel and Composite Structures
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• 제49권4호
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• pp.441-456
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• 2023

Aiming at the development trend of light weight and high strength of engineering structures, this paper experimentally investigated the seismic performance of circular-in-square high-strength concrete-filled double skin steel tubular (HCFDST) stub columns with out-of-code width-to-thickness (B/t) ratios. Typical failure mode of HCFDST stub columns appeared with the infill material crushing, steel fracture and local buckling of outer tubes as well as the inner buckling of inner tubes. Subsequently, the detailed analysis on hysteretic curves, skeleton curves and ductility, energy dissipation, stiffness degradation and lateral force reduction was conducted to reflect the influences of hollow ratios, axial compression ratios and infill types, e.g., increasing hollow ratio from 0.54 to 0.68 and 0.82 made a slight effect on bearing capacity compared to the ductility coefficients; the higher axial compression ratio (e.g., 0.3 versus 0.1) significantly reduced the average bearing capacity and ductility; the HCFDST column SCFST-6 filled with concrete obviously displayed the larger initial secant stiffness with a percentage 34.20% than the column SCFST-2 using engineered cementitious composite (ECC); increasing hollow ratios, axial compression ratios could accelerate the drop speed of stiffness degradation. The out-of-code HCFDST stub columns with reasonable design could behave favorable hysteretic performance. A theoretical model considering the tensile strength effect of ECC was thereafter established and verified to predict the moment-resisting capacity of HCFDST columns using ECC. The reported research on circular-in-square HCFDST stub columns can provide significant references to the structural application and design.

• 한국식품과학회지
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• 제44권4호
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• pp.434-440
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• 2012

쌀 유래 세라마이드를 함유한 미용보조제의 섭취에 관한 위약 대조, 이중 맹검 연구가 건조함으로 인해 항상 피부가 거친 경향이 있었던 33명의 피험자들에게 실시되어 다음과 같은 결과가 얻어졌다. 섭취 6주 후 피부과적 진단에 따르면 건조함, 홍조, 화장 유지력, 가려움 등의 관찰항목에서 플라시보 군 및 세라마이드군 모두에서 개선효과가 있었으나 플라시보 군 에서는 개선율이 43.8%인 반면, 세라마이드 군의 개선율은 64.7%로 높았다. 수분량, 유분량, pH 측정결과를 보면, 플라시보 군과 세라마이드 군 모두에서 유분량 및 pH 관련하여 유의한 변화는 없었다. 그러나 수분량에서는 플라시보 군에서 유의한 변화가 없었던 반면, 세라마이드 군에서는 6주 후 유의한 수분량 증가가 있었다. 3차원 현미경 경피분석시스템에 의한 분석결과에 따르면, 세라마이드 군에서는 Kurtosis, 유연성지수(SEsm), 거�s지수(SEr), 각질 및 인설 지수(SEsc), 주름지수(SEw)가 유의하게 개선되었으나 플라시보 군에서는 어떠한 유의한 변화도 관찰되지 않았다. 이는 이중맹검법으로 실시된 이번 연구에서 피부과적 진단이 명백한 플라시보 효과를 보인 점과 대비된다. 이로써 의사들에 의한 관찰과 더불어 과학적이고 객관적인 측정에 의해 세라마이드는 피부건조함과 거�s을 개선하는 데 효과가 있음이 입증되었고 경구섭취로 그 효과가 나타났다. 상기 결과는 쌀 유래 세라마이드 보조제의 장기간에 걸친 섭취가 보습, 피부의 유연성 유지에 효과적이고 따라서 효과적인 피부미용식품임을 보여준다.

• Archives of Plastic Surgery
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• 제32권2호
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• pp.245-249
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• 2005

Various surgical procedures have been described for treating osmidrosis axillare. Elimination of the apocrine glands is prime goal. Optimal operative procedure is characterized as follows: minimal axillary scar(which has cosmetic merits), less complications such as hematoma and seroma, short and less painful recuperating period, minimal damage to the skin and low recurrence rate. Three types of incision technique in subdermal shaving method have beeb commoly used. First, single incision method has an advantage of minimal scarring but more recurrence due to incomplete removal of apocrine glands may occur. Second, double incision technique(Bipedicled flap) has advantages of complete excision, low recurrence rate and relatively minimal scarring, but it could cause frequent necrosis of skin and folding of skin flap. Skoog's method is the third method, which makes four flaps by offset cruciate incisions. It is a better technique in aspect of complete excision of apocrine glands and low recurrence rate but has disadvantages such as development of hypertrophic scar or scar contracture in the line that lies perpendicular to natural axillary skin crease. We used a modified procedure which has shorter length in vertical and transverse incision compared with the classic Skoog's method. We dissected further subcutaneous tissue through the diamond-shaped incision and utilize wide operation field that provide adequate excision of subdermal tissue and proper hemostasis. Between 1999 and 2004, we operated 160 osmidrosis axillare in 80 patients in this technique. Most patients obtained satisfactory result with very low complications. Hematoma or seroma 3.1% Infection 0.6% Partial wound disruption 10% Recurrence 1.2%. Modified Skoog's method for treating osmidrosis axillae could be a optimal technique providing wide operation field for adequate excision of apocrine glands and proper hemostasis and leaving relatively inconspicuous scar and low incidence of scar contracture.

• Animal cells and systems
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• 제16권3호
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• pp.207-214
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• 2012

Burns are one of the most devastating forms of trauma and wound healing is a complex and multicellular process, which is executed and regulated by signaling networks involving numerous growth factors, cytokines, and chemokines. Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) was specifically produced from rice cell culture through use of a recombinant technique in our laboratory. The effect of rhGM-CSF on promotion of deep second-degree burn wound healing on the back skin of a hamster model was evaluated through a randomized and double-blind trial. As macroscopic results, hamster skins of the experimental groups showed earlier recovery by new epidermis than the control groups. Immunohistochemical reactions of proliferating cell nuclear antigen and transforming growth factor-b1, which are indicators of cell proliferation, were more active in the experimental group, compared with the control group. On electron microscopy, basal cells in the epidermis of the experimental group showed oval nuclei, prominent nucleoli, numerous mitochondria and abundant free ribosomes. In addition, fibroblasts contained well-developed rough endoplasmic reticulum with dilated cisternae. Bundles of collagen fibrils filled the extracellular spaces. Particularly, ultrastructural features indicating active metabolism for regeneration of injured skin at 15 days after burn injury, including abundant euchromatin, plentiful free ribosomes, and numerous mitochondria, were observed. These findings suggest that use of rhGM-CSF could result in accelerated deep second-degree burn wound healing in animal models.

• Composites Research
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• 제26권4호
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• pp.259-264
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• 2013

본 연구에서는 기계적 전기적 기능을 모두 만족하는 다중대역 스킨구조물에서의 복사 소자를 2중 사출으로 제작하였다. 추후 외부 스킨 구조 변형에 따른 복사 소자의 안정성을 검증하기 위하여 충격 및 좌굴에 대한 시험과 축 하중과 전단 하중에 대한 강도 해석을 실시하였다. 그리고 다중 대역 안테나 스킨 구조의 복사 소자에 대한 실험적 방법과 해석적 방법을 통한 강도 분석 결과, 구조의 허용 하중을 예측하고 충격과 좌굴에 대한 안정성을 평가할 수 있었다.