• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제30권4호
• /
• pp.308-315
• /
• 2004

Aim: The aim of this study was to investigate the mechanism of promoted skin wound healing in skin defects with primary cultured oral mucosal keratinocytes. Materials and methods: Thirty adult female nude mice weighing $20{\pm}2g$ were used for the experiment. Primary cultured and suspended oral mucosal keratinocytes, labeled with BrdU, were scattered onto $1.5cm{\times}1.5cm$ sized full thickness skin defects in the experimental group(N=15), and no grafts were placed the control group(N=15). They were sacrificed at 3 days, 1 week and 2 weeks after the treatment respectively. Histological examination of each wounds were performed to review the healing progress on measuring the length from the wound margin to regenerating epithelial front. The role of keratinocytes were assessed by double immunohistochemical staining with Anti-BrdU and Anti-cytokeratin AE1/3. Results: In the experimental group the wound was completely covered with regenerating epithelia in 2 weeks, but partially regenerated in the control group. The immunohistochemical studies unexpectedly reveal that most of regenerating epithelial cells were induced from marginal epithelium of the margin, not from the scattered keratinocytes. Conclusion: We could successfully confirm that graft of primary cultured oral mucosal keratinocytes promotes the regeneration of skin defects.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2003년도 하계학술대회 논문집
• /
• pp.176-176
• /
• 2003

• 한국응용과학기술학회지
• /
• 제38권4호
• /
• pp.915-921
• /
• 2021

본 연구에서는 피부 보습 및 진정효능을 갖는 비타민 B5인 Pantothenic acid (PA)의 피부 투과율을 개선시키기 위해 고형지질나노입자(SLN)를 설계하였다. SLN은 지질과 유화제의 종류를 변화하여 여러 조성으로 제조하였고, PA는 이중 에멀젼 가온 용융유화법으로 SLN 내에 봉입하였다. 제조 된 PA 봉입 SLN은 입자의 물리화학적 특성인 입자크기, 다분산 지수, 제타전위, 봉입율을 평가하였다. 피부 투과시험의 경우 인체 유래 인조 피부 조직을 사용하였다. 제조 된 PA 봉입 SLN의 입자크기는 192.15 - 369.87 nm이었고, 제타전위는 -21.39 - -40.55 mV이었다. SLN 내 PA의 평균 봉입효율은 44.36 - 57.16%이었고, 평균 봉입율은 12.60 - 16.36%이었다. PA 봉입 SLN의 피부 투과 결과는 SLN을 적용한 제형이 적용하지 않은 PA 용액 보다 약 3.8 - 8.8 배 PA의 피부 투과율이 개선되었다. 본 연구에서 제조 된 SLN은 PA의 피부 투과율을 개선하였음을 보여주었다. 특히, glyceryl behenate와 Span 60을 사용한 SLN이 PA의 피부 투과율이 가장 높은 결과를 보여 주었다.

• 대한화장품학회지
• /
• 제47권2호
• /
• pp.179-184
• /
• 2021

각질층은 피부의 가장 바깥쪽에 위치하여 피부 내 수분을 유지시킨다. 피부 보습은 각질층 내 천연보습인자(natural moisturizing factors, NMF)에 의존하는데, NMF 중 아미노산이 가장 많은 비율을 차지한다. 본 연구에서는 NMF 중 serine (Ser)의 피부 투과율을 개선시키기 위해 생체 적합한 고형지질인 stearic acid 기반 고형지질나노입자(solid lipid nanoparticles, SLNs)를 설계하였다. Ser 봉입 SLNs은 이중 가온용융유화법으로 제조하였다. 평균 입자 크기는 256.30 ~ 416.93 nm이었고 제타전위는 -17.60 ~ -35.27 mV이었다. 유화제의 지용성 또는 친수성의 정도가 각각 높아질수록 입자크기 작아지고 안정성 및 봉입율이 높아지는 경향을 보였다. Ser의 피부 투과 연구를 위해 인체 표피 유래 피부 조직(SkinEthic^TM RHE)을 사용하였다. Ser의 피부 투과결과 SLN을 적용한 제형이 대조군인 Ser 용액에 비해 약 4.1 ~ 6.2 배 투과율이 개선되었음을 확인하였다. 유화제의 지용성 또는 친수성의 정도가 각각 높아질수록 Ser의 피부 투과율이 높아지는 경향을 보였다. 따라서, Ser이 봉입된 SLN은 기능성화장품의 보습효과 처방을 위한 경피흡수 제형으로 사용될 수 있을 것으로 기대된다.

• 치과방사선
• /
• 제27권2호
• /
• pp.63-81
• /
• 1997

This study was performed in order to identify changes of the plasma membrane proteins in rat submandibular gland tumors induced by 7,12-dimethylbenz[a]anthracene [DMBA] and X-irradiation. Two kinds of tumor associated membrane proteins (protein A and B) were isolated with 3 M KCl extraction from rat submandibular gland tumors induced by DMBA and X-irradiation. To identify their antigenicities, immunoelectrophoresis and double immunodiffusion was carried out with various proteins extracted from liver, heart, skin and pancreas of adult rats and from embryonic liver, heart and skin. The rabbit antisera against the protein A did not cross-react with any of the proteins extracted from the above mentioned tissues, suggesting that protein A might be tumor specific antigen. However, the rabbit antisera against protein B was precipitated with proteins extracted from the liver of adult and embryonic rats. Polyacrylamide gel electrophoresis of these two proteins (A and B) showed that protein A was a dimer with molecular weights of 69,000 and 35,000 dalton, whereas protein B was a monomer with molecular weight of 50,000 dalton.

• Steel and Composite Structures
• /
• 제36권2호
• /
• pp.187-196
• /
• 2020

Double skin composite wall system owns several structural merits in terms of high load-carrying capacity, large axial stiffness, and favorable ductility. A recently proposed form of truss connector was used to bond the steel plates to the concrete core to achieve good composite action. The structural behavior of rectangular high walls under compression and T-shaped high walls under eccentric compression has been investigated by the authors. Furthermore, the influences of the truss spacings, the wall width, and the faceplate thickness have been previously studied by the authors on short walls under uniform compression. This paper experimentally investigated the effect of width-to-thickness ratio on the compressive behavior of short walls. Compressive tests were conducted on three short specimens with different width-to-thickness ratios. Based on the test results, it is found that the composite wall shows high compressive resistance and good ductility. The walls fail by local buckling of steel plates and crushing of concrete core. It is also observed that width-to-thickness ratio has great influence on the compressive resistance, initial stiffness, and strain distribution across the section. Finally, the test results are compared with the predictions by modern codes.

• Steel and Composite Structures
• /
• 제27권5호
• /
• pp.577-598
• /
• 2018

The imperfect steel-concrete interface bonding is an important deficiency of the concrete-filled double skin tubular (CFDST) columns that led to separating concrete and steel surfaces under lateral loads and triggering buckling failure of the columns. To improve this issue, it is proposed in this study to use longitudinal and transverse steel stiffeners in CFDST columns. CFDST columns with different patterns of stiffeners embedded in the interior or exterior surfaces of the inner or outer tubes were analyzed under constant axial force and reversed cyclic loading. In the finite element modeling, the confinement effects of both inner and outer tubes on the compressive strength of concrete as well as the effect of discrete crack for concrete fracture were incorporated which give a realistic prediction of the seismic behavior of CFDST columns. Lateral strength, stiffness, ductility and energy absorption are evaluated based on the hysteresis loops. The results indicated that the stiffeners had determinant role on improving pinching behavior resulting from the outer tube's local buckling and opening/closing of the major tensile crack of concrete. The lateral strength, initial stiffness and energy absorption capacity of longitudinally stiffened columns with fixed-free end condition were increased by as much as 17%, 20% and 70%, respectively. The energy dissipation was accentuated up to 107% for fixed-guided end condition. The use of transverse stiffeners at the base of columns increased energy dissipation up to 35%. Axial load ratio, hollow ratio and concrete strength affecting the initial stiffness and lateral strength, had negligible effect of the energy dissipation of the columns. It was also found that the longitudinal stiffeners and transverse stiffeners have, respectively, negative and positive effects on ductility of CFDST columns. The conclusions, drawn from this study, can in turn, lead to the suggestion of some guidelines for the design of CFDST columns.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1996년도 춘계 학술대회논문집
• /
• pp.58-67
• /
• 1996

This paper describes some computational results of various energy and environmental systems using Patankar's SIMPLE method. The specific topics handled in this study are jet bubbling reactor for flue gas desulfurization, cyclone-type afterburner for incineration, 200m tall stack for 500 MW electric power generation, double skin and heat storage systems of building energy saving for the utilization of solar heating, finally turbulent combustion systems with liquid droplet or pulverized coal particle. A control-volume based finite-difference method with the power-law scheme is employed for discretization. The pressure-velocity coupling is resolved by the use of the revised version of SIMPLE, that is, SIMPLEC. Reynolds stresses are closed using the standard $k-{\varepsilon}$ and RNG $k-{\varepsilon}$ models. Two-phase turbulent combustion of liquid drop or pulverized coal particle is modeled using locally-homogeneous, gas-phase, eddy breakup model. However simple approximate models are incorporated for the modeling of the second phase slip and retardation of ignition without consideration of any detailed particle behavior. Some important results are presented and discussed in a brief note. Especially, in order to make uniform exit flow for the jet bubbling reactor, a well-designed structure of distributor is needed. Further, the aspect ratio in the double skin system appears to be one of important factors to give rise to the visible change of the induced air flow rate. The computational tool employed in this study, in general, appears as a viable method for the design of various engineering system of interest.

• Steel and Composite Structures
• /
• 제36권5호
• /
• pp.507-519
• /
• 2020

Double skin composite walls are increasingly popular and have been applied to many safety-related facilities. They come from the concept of composite slabs. Conventional connectors such as shear studs and binding bars were used in previous studies to act as the internal mechanical connectors to lock the external steel faceplates to the concrete core. However, the restraint effects of these connectors were sometimes not strong enough. In this research, a recently proposed unique type of steel truss was employed along the wall height to enhance the composite action between the two materials. Concrete-filled tube columns were used as the boundary elements. Due to the existence of boundary columns, the restraints of steel faceplates to the concrete differ significantly for the walls with different widths. Therefore, there is a need to explore the effect of height-to-width ratio on the structural behavior of the wall. In the test program, three specimens were designed with the height of 3000 mm, the thickness of 150 mm, and different widths, to simulate the real walls in practice. Axial compression was applied by two actuators on the tested walls. The axial behavior of the walls was evaluated based on the analysis of test results. The influences of height-to-width ratio on structural performance were evaluated. Finally, discussion was made on code-based design.

• Archives of Plastic Surgery
• /
• 제41권4호
• /
• pp.398-402
• /
• 2014

Background Non-incisional blepharoplasty is a simple, less invasive method for creating a more natural-appearing double eyelid than classical incisional blepharoplasty. However, in aging patients, non-incisional blepharoplasty is not effective due to more severe blepharochalasis. Traditionally, incisional blepharoplasty is a common surgical method used for older patients, but blepharoplasty in elderly patients typically results in prolonged recovery times, and final blepharoplasty lines may be located in unintended or asymmetrical positions. Here, we introduce a new modified combination technique for geriatric blepharoplasty. Methods A total of ten patients were treated from July 2010 through July 2012 using the combination method. First, we performed non-incisional blepharoplasty using tarsodermal fixation. Then, incisional blepharoplasty with additional elliptical excision of the upper eyelid skin was performed. We removed pretarsal tissue, fat, the orbicularis oculi muscle, and orbital fat. Telephone surveys were administered to all patients for follow-up. The questionnaire was composed of eight questions that addressed recurrence and satisfaction with aesthetics and the procedure. Results A total of nine patients (90%) responded to the telephone survey. All cases of moderate to severe blepharochalasia were corrected and there were no major complications. Patients who underwent blepharoplasty had higher satisfaction scores. All patients were satisfied with the postoperative shapes of their eyelids. Conclusions The advantages of the proposed technique include: ease of obtaining a natural-looking fold with symmetry at the desired point; reproducible methods that require short operation times; fast postoperative recovery that results in a natural-appearing double-eyelid line; and high patient satisfaction.