Hydrogel Nanospike Patch as a Flexible Anti-Pathogenic Scaffold for Regulating Stem Cell Behavior

Park, Sunho,Park, Hyun-Ha,Sun, Kahyun,Gwon, Yonghyun,Seong, Minho,Kim, Sujin,Park, Tae-Eun,Hyun, Hoon,Choung, Yun-Hoon,Kim, Jangho,Jeong, Hoon Eui American Chemical Society 2019 ACS NANO Vol.13 No.10

<P>Vertically aligned nanomaterials, such as nanowires and nanoneedles, hold strong potential as efficient platforms onto which living cells or tissues can be interfaced for use in advanced biomedical applications. However, their rigid mechanical properties and complex fabrication processes hinder their integration onto flexible, tissue-adaptable, and large-area patch-type scaffolds, limiting their practical applications. In this study, we present a highly flexible patch that possesses a spiky hydrogel nanostructure array as a transplantable platform for enhancing the growth and differentiation of stem cells and efficiently suppressing biofilm formation. <I>In vitro</I> studies show that the hydrogel nanospike patch imposes a strong physical stimulus to the membranes of stem cells and enhances their osteogenic, chondrogenic, and adipogenic differentiation and the secretion of crucial soluble factors without altering cell viability. At the same time, the array exhibits effective bactericidal properties against Gram-positive and Gram-negative bacteria. <I>In vivo</I> studies further demonstrate that the flexible hydrogel patch with its spiky vertical nanostructures significantly promotes the regeneration of damaged cranial bone tissues while suppressing pathogenic bacterial infections in mouse models.</P> [FIG OMISSION]</BR>

공공임대주택과 민간임대주택의 주거 만족도 영향요인 및 차이 분석

박선호(Park, Sunho),김남정(Kim, Namjung),박환용(Park, Hwanyong) 한국주거환경학회 2021 주거환경(한국주거환경학회논문집) Vol.19 No.4

본 연구는 민간임대주택을 비교 대상으로 하여 공공임대주택의 주거 만족도 영향요인을 분석하고, 공공임대주택의 만족도를 높이기 위한 정책적 시사점을 도출하는데 연구의 목적을 갖고 있다. 연구의 공간적 범위는 전국이며, 공공임대주택과 민간임대주택의 주거 만족도 자료는 정부가 가장 최근에 실시한 2019년 ‘주거실태조사’의 결과를 활용하였다. 본 연구는 로지스틱 회귀모형을 활용하여 다음과 같은 분석결과를 도출하였다. 첫째, 공공임대주택과 민간임대주택에 있어서 전반적인 주택 만족도의 영향요인은 ‘안전·위생상태’요인, ‘방수·난방상태’요인, ‘소음상태’요인이 공통적으로 영향을 미치는 것으로 분석되었다. 먼저, 공공임대주택의 경우는 ‘방수·난방’요인이 1단위(1단계) 증가(상승)하면 전반적인 주택 만족도가 높아질 확률이 4.549배 증가하고, ‘안전·위생상태’요인은 전반적인 주택 만족도 수준을 높일 확률이 3.697배, ‘소음상태’요인은 2.191배인 것으로 나타났다. 다음으로 민간임대주택은 ‘방수·난방상태’요인의 수준이 1단위(1단계) 증가(상승)하면 전반적인 주택 만족도가 높아질 확률이 3.871배 증가하고, ‘안전·위생상태’요인은 전반적인 주택 만족도를 높일 확률이 3.587배, ‘소음상태’요인은 1.943배 증가하는 것으로 나타났다. 주택유형의 경우는 비아파트에서 아파트로 주택유형이 변화되면 전반적인 주택 만족도 수준이 불만족에서 만족 수준으로 개선될 확률이 1.328배 증가하고, 월소득은 소득이 증가할수록 만족도 수준도 증가하는 경향을 갖는 것으로 나타났다. 이 외에도 환기의 상태 수준이 ‘불량’에서 ‘양호’로 개선되면 전반적인 주택 만족도가 높아질 확률이 2.094배가 증가하고, 채광의 경우는 1.460배가 증가하는 것으로 분석되었다. 둘째, 전반적인 주거환경 만족도에 미치는 영향요인은 공공임대주택과 민간임대주택에서 공통적으로 ‘외부시설 접근환경’요인, ‘거주 환경성’요인, ‘주차·보행환경’요인 모두 영향을 미치는 것으로 분석되었다. 또한, 요인 구성에는 포함되지 않았으나 공원·녹지 접근성, 교육시설 이용성, 방범, 이웃관계에 대한 만족도가 영향을 미치는 것으로 분석되었다. 먼저, 공공임대주택의 경우는 ‘외부시설 접근환경’요인의 만족도 수준이 1단위(1단계) 증가(상승)하면 전반적인 주거환경 만족도 수준이 높아질 확률이 6.334배 증가하는 것으로 분석되었다. ‘거주 환경성’요인은 2.747배, ‘주차·보행환경’요인은 2.007배가 증가하는 것으로 나타났다. 월소득의 경우는 Exp(B)의 값이 0.998배로서 만족도 수준 변화에 미치는 확률은 매우 적지만 월소득이 높아질수록 전반적인 주거환경 만족도 수준이 낮아지며, 반대로 소득이 낮아질수록 만족도 수준이 높아지는 경향을 갖고 있는 것으로 나타났다. 지역1의 경우는 비수도권보다 수도권에 거주할 경우에 전반적인 주거환경 만족도가 높아질 확률이 1.684배로 나타났다. 다음으로 민간임대주택은 ‘외부시설 접근환경’요인의 만족도 수준이 1단위(1단계) 증가(상승)하면 전반적인 주거환경 만족도가 높아질 확률이 3.492배 증가하는 것으로 분석되었다. ‘거주 환경성’요인의 만족도 수준이 1단위 증가하면 전반적인 주거환경 만족도가 2.020배 증가하고, ‘주차·보행환경’요인은 1.906배 증가하는 것으로 나타났다. 지역1에 있어서 도에서 광역시·특별시로 거주지가 이전되면 전반적인 주거환경 만족도 수준이 개선될 확률이 1.229배 증가하고, 주택 노후도의 경우는 1.486배 증가하는 것으로 나타났다. 이러한 분석결과를 놓고 볼 때, 공공임대주택을 공급함에 있어서 방수, 균열, 난방·단열 등 ‘방수·난방상태’와 관련된 건축물의 물리적 환경의 질적 향상에 노력을 기울여야 할 필요가 있다. 건축물의 상태가 개선될 때 전반적인 주택 만족도가 높아질 확률이 가장 크기 때문이다. 또한, 공공임대주택의 건설·공급 입지와 단지내 위치에 대한 계획적 배려가 요구된다. 의료시설·상업시설·공공기관·문화시설·대중교통 접근성을 개선될 때 전반적인 주거환경 만족도가 높아질 확률이 가장 큰 것으로 분석되었기 때문이다. 이 같은 맥락에서 수요가 많은 도심 내에서 공공참여형 또는 공공주도형 정비사업 등을 통해 공공임대주택을 확보하고 기존 공공임대주택의 리모델링이나 재건축을 통해 양질의 임대주택 수요에 부응해 나갈 필요가 있다고 하겠다. There is growing demand for more emphasis to be placed on the quality of public rental housing rather than only expanding its supply. The Korean government plans to extend eligibility for public rental housing for middle income households. Quality of public housing is more likely to be enhanced when we accurately understand factors affecting residents’ level of satisfaction. This study examines the factors affecting residents’ satisfaction with public rental housing compared with private rental housing. We analyzed the micro data obtained from the 2019 Korean Housing Survey conducted by the Korean Ministry of Land, Infrastructure and Transport. Overall housing facility satisfaction levels with public and private rental housing are commonly affected by “water-proofing and heating” followed by, in order of importance, “security and sanitation” and “noise.” Apart from this, satisfaction with private rental housing is influenced by “income,” “types of building,” “ventilation,” and “sun lighting.” In addition, residential environment satisfaction levels with public and private rental housing are commonly affected by “accessibility of neighborhood facilities,” “environmental aspects for residents,” and “car-park and pedestrian-friendliness,” in order of importance. Other common variables explaining residents’ overall satisfaction with the residential environment are parks, green areas, and educational facilities. Although these factors are common determinants of satisfaction for both types of housing, in terms of how strongly each factor influences satisfaction, there is a significant difference between public and private rental housing.

해상 물류 효율성을 위한 선박의 전자적 처리 수단과의 항만 정보 연계 방안 연구

박순호(Park Sunho),박원재(Park Wonjae),박새롬(Park Saerom) 한국통신학회 2014 한국통신학회 학술대회논문집 Vol.2014 No.6

Nano-enabled Biosystems Engineering for Future Agriculture

( Sunho Park ),( Yonghyun Gwon ),( Woochan Kim ),( Hyoseong Kim ),( Jangho Kim ) 한국농업기계학회 2023 한국농업기계학회 학술발표논문집 Vol.28 No.1

Despite progress in agricultural prosperity, agriculture faces some problems such as the drop in profitability and the reduction in deforestation, necessitating development of an effective and productive agricultural system. To encourage a productive agricultural system, biosystems engineering have a important role in the impending agri-tech revolution to promote the proper regulatory arrangement. Recently, nanotechnology regards as emerged technology to support biosystems engineering for sustainable agriculture incorporating food security and human health. In this study, we proposed nano-enabled biosystems engineering for future advanced agriculture. Specifically, we reveal that nanomaterials (i.e., graphene) can promote the plant and crop growth, showing the enhanced florescence and the increased sugar content. In addition, biocompatible nanoparticles can improve the pesticide performance and plant growth without cytotoxicity. In addition, nanotopography inspired by extracellular matrix can induce the animal tissue regeneration. Using nano-enabled biosystems engineering, we can confirm their potential use for improving functions of biosystems in the near future.

Numerical analysis of the three-dimensional cloud cavitating flow around a twisted hydrofoil

Park, Sunho,Hyung Rhee, Shin IOP Publishing 2013 Fluid dynamics research Vol.45 No.1

Investigation on the wall function implementation for the prediction of ship resistance

Sunho Park,Se Wan Park,Shin Hyung Rhee,Sang Bong Lee,Jung-Eun Choi,Seon Hyung Kang 대한조선학회 2013 International Journal of Naval Architecture and Oc Vol.5 No.1

A computational fluid dynamics (CFD) code, dubbed SNUFOAM, was developed to predict the performance of ship resistance using a CFD tool kit with open source libraries. SNUFOAM is based on a pressure-based cellcentered finite volume method and includes a turbulence model with wall functions. The mesh sensitivity, such as the skewness and aspect ratio, was evaluated for the convergence. Two wall functions were tested to solve the turbulent flow around a ship, and the one without the assumption of the equilibrium state between turbulent production and dissipation in the log law layer was selected. The turbulent flow around a ship simulated using SNUFOAM was compared to that by a commercial CFD code, FLUENT. SNUFOAM showed the nearly same results as FLUENT and proved to be an alternative to commercial CFD codes for the prediction of ship resistance performance.

Virus in the Urine of Healthy People and Patients with Infectious Diseases

Sunho Park,Eui Tae Kim,Jung-Sik Huh 대한요로생식기감염학회 2021 Urogenital Tract Infection Vol.16 No.2

There has been a sustained effort to overcome the multiple infectious diseases that confront humankind. Urinary tract infections (UTIs) are most commonly caused by bacterial pathogens, primarily Escherichia coli. However, UTIs by viral pathogens have not been significantly reported. The human urinary tract, both in the healthy and diseased states, is home to many viruses despite the traditional belief that urine is sterile in healthy individuals. The most common viral pathogens found in the urinary tract are the human polyomavirus (BK virus), adenovirus, cytomegalovirus, and herpes simplex virus type-1 and type-2. Research should continue to investigate whether these viruses cause clinical infections or are mere colonizers of the urinary tract.

Influence of blade deformation and yawed inflow on performance of a horizontal axis tidal stream turbine

Park, Sewan,Park, Sunho,Rhee, Shin Hyung Elsevier 2016 RENEWABLE ENERGY Vol.92 No.-

<P><B>Abstract</B></P> <P>For a better design of tidal stream turbines operated in off-design conditions, analyses considering the effects of blade deformation and yawed inflow conditions are necessary. The flow load causes deformation of the blade, and the deformation affects the turbine performance in return. Also, a yawed inflow influences the performance of the turbine. As a validation study, a computational fluid dynamics (CFD) simulation was carried out to predict the performance of a horizontal axis tidal stream turbine (HATST) with rigid blades. The numerical uncertainty for the turbine performance with blade deformation and a yawed inflow was evaluated using the concept of the grid convergence index (GCI). A fluid–structure interaction (FSI) analysis was carried out to estimate the performance of a turbine with flexible composite blades, with the results then compared to those of an analysis with rigid blades. The influence of yawed inflow conditions on the turbine performance was investigated and found to be important in relation to power predictions in the design stages.</P> <P><B>Highlights</B></P> <P> <UL> <LI> De-twisted blade by torsion reduced the power. </LI> <LI> The tip vortex was significantly suppressed by the deforming blade. </LI> <LI> The yawed inflow deteriorated the performance of the turbine. </LI> </UL> </P>

Development of Free-surface Decomposition Method and Its ApplicationDevelopment of Free-surface Decomposition Method and Its Application

Park, Sunho Korean Society of Ocean Engineers 2017 Journal of advanced research in ocean engineering Vol.3 No.2

With the development of computational fluid dynamics (CFD), studies on shipbuilding and maritime issues including free-surface wave flow have been conducted. Although the volume of fluid (VOF) and level-set methods are widely used to study the free-surface wave flow, disadvantages exist. In particular, it takes a long time to obtain solutions. In this study, a free-surface capturing code is developed for ship and offshore structures. The developed code focuses on accuracy and computation time. Open source CFD libraries, termed OpenFOAM, are used to develop the code. The results obtained using the developed code are compared with those obtained using interFoam. The results show that the developed code could be used to capture the free-surface wave flow without numerical diffusion; moreover, the accuracy of the developed code is largely the same as that of interFoam.

Viscoelastic properties of a 3D-Printable high-dielectric paste with surface-modified BaTiO₃

Park, Jae Yun,Kang, Yi Young,Yoon, Hyun Woo,Park, No Kyun,Jo, Yejin,Jeong, Sunho,Won, Jong Chan,Kim, Yun Ho Elsevier 2018 Composites science and technology Vol.159 No.-

<P><B>Abstract</B></P> <P>In this study, a polystyrene-block-polyisoprene-block-polystyrene (SIS) based dielectric paste was fabricated using barium titanate (BT) as dielectric filler in order to produce organic-inorganic composites for 3D dispenser printing applications. Since a high loading of inorganic filler is generally required to obtain high dielectric properties, the surface of BT was modified with two different phosphonic acids having functional groups resembling the groups contained in the block copolymer, in order to achieve a high compatibility between the filler and the polymer matrix. Upon incorporation of 80 wt% of BT in SIS, the dielectric constant was found to be approximately 3 times higher than that of bare SIS. The surface modification of the filler enhanced its dispersion within the polymer matrix, as confirmed by the surface morphology of the composite film at a high filler content. The desired viscoelasticity was achieved through the fine-tuning of the total solid content, and consequently, the potential application of the composite as 3D printable paste was demonstrated through the formation of a layer-by-layer printed structure on a flexible substrate.</P>