Perfusable micro-vascularized 3D tissue array for high-throughput vascular phenotypic screening

Yu James,Lee Somin,Song Jiyoung,이승렬,Kim Suryong,Choi Hyeri,Kang Habin,Hwang Yunchan,Hong Young-Kwon,전누리 나노기술연구협의회 2022 Nano Convergence Vol.9 No.16

Microfluidic organ-on-a-chip technologies have enabled construction of biomimetic physiologically and pathologically relevant models. This paper describes an injection molded microfluidic platform that utilizes a novel sequential edge-guided patterning method based on spontaneous capillary flow to realize three-dimensional co-culture models and form an array of micro-vascularized tissues (28 per 1 × 2-inch slide format). The MicroVascular Injection-Molded Plastic Array 3D Culture (MV-IMPACT) platform is fabricated by injection molding, resulting in devices that are reliable and easy to use. By patterning hydrogels containing human umbilical endothelial cells and fibroblasts in close proximity and allowing them to form vasculogenic networks, an array of perfusable vascularized micro-tissues can be formed in a highly efficient manner. The high-throughput generation of angiogenic sprouts was quantified and their uniformity was characterized. Due to its compact design (half the size of a 96-well microtiter plate), it requires small amount of reagents and cells per device. In addition, the device design is compatible with a high content imaging machine such as Yokogawa CQ-1. Furthermore, we demonstrated the potential of our platform for high-throughput phenotypic screening by testing the effect of DAPT, a chemical known to affect angiogenesis. The MV-IMPACT represent a significant improvement over our previous PDMS-based devices in terms of molding 3D co-culture conditions at much higher throughput with added reliability and robustness in obtaining vascular micro-tissues and will provide a platform for developing applications in drug screening and development.

From microchannels to microphysiological systems: Development of application specific devices

Yu, James,Lim, Jungeun,Choi, MunSeok,Chung, Minhwan,Jeon, Noo Li Elsevier 2018 MICROELECTRONIC ENGINEERING Vol.202 No.-

<P><B>Abstract</B></P> <P>Microphysiological systems are an emerging field of biomimetic technologies which utilize microfluidics to reconstitute tissue functions within an <I>in vitro</I> environment. Microfluidic organ-on-a-chip platforms exist at the intersection of biology and engineering, straddling the forefront of cutting edge biological research, fluidics, and microfabrication technologies to emulate complex <I>in vitro</I> tissue systems within a highly controllable, accessible, and observable, <I>in vitro</I> environment. Although the advance of cell culture technologies from comparatively rudimentary conventional 2D petri dish based cultures to sophisticated 3D tissue engineering may seem futuristic, the microfluidic engineering concepts behind organ-on-a-chip technologies have deep historical roots which span over half a century. In this paper, we will discuss the shortcomings of conventional cell culture and organ modeling platforms which contributed to the demand for <I>in vitro</I> tissue engineering, as well as provide a background in the technological foundations of microfluidics. We will further recount a brief history of microfluidic cell culture, with emphasis on important developments in fabrication practices and methods of engineering biologically relevant microenvironmental conditions, before discussing the present state of organ specific microfluidic platforms and the future directions that the field may take to overcome present challenges.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Strategies of Maize Breeding for Resistance to Fusarium Ear Rot and Fumonisin Contamination

Jin Yu,M.S. Eller,Yoon-Sup So,James B. Holland,Sun-Hee Woo,Charlie Zilla 한국육종학회 2012 한국육종학회 심포지엄 Vol.2012 No.07

Is backcrossing a good strategy for improving elite lines for quantitative traits in general? Results reported here demonstrate the effectiveness of a backcrossing program for improving quantitatively inherited disease resistance traits, which are strongly influenced by the environment. Through backcross breeding, we were able to improve an important commercial inbred line, FR1064, for ear rot and fumonisin contamination resistance without significantly lowering its yield potential, even with the use of a donor line with poor agronomic potential. Following one generation of selection on advanced backcross-derived lines, gains were observed for the primary trait of interest in advanced inbred generations. Following two generations of selection, we improved potential performance for ear rot resistance and reduced fumonisin accumulation in the 19 selected lines without significantly affecting important agronomic characteristics such as plant height, ear height, or flowering time compared to the recurrent parent, FR1064. The 19 selected lines were also significantly more resistant to ear rot under inoculated conditions than the FR1064 topcross without exhibiting significant reductions in topcross grain yield or other agronomic traits. Several individual lines were identified that were not statistically different from GE440 for ear rot or fumonisin content as inbreds or from the GE440 topcross for ear rot. These lines exhibited topcross yields comparable to the FR1064 topcross, although they were not competitive with commercial check yields. Thus, from a practical standpoint, the backcrossing method was effective at improving quantitative disease resistance in an elite commercial line using an unadapted donor parent. We also genotyped selected lines at DNA markers linked to ear rot and fumonisin resistance quantitative trait loci (QTL) identified in the BC1 generation of this cross to determine which QTL demonstrated allele frequency shifts due to selection.

Strategies of Maize Breeding for Resistance to Fusarium Ear Rot and Fumonisin Contamination

Jin Yu,M.S. Eller,Charlie Zilla,Yoon-Sup So,James B. Holland,Sun-Hee Woo 한국육종학회 2012 한국육종학회 심포지엄 Vol.2012 No.07

Is backcrossing a good strategy for improving elite lines for quantitative traits in general? Results reported here demonstrate the effectiveness of a backcrossing program for improving quantitatively inherited disease resistance traits, which are strongly influenced by the environment. Through backcross breeding, we were able to improve an important commercial inbred line, FR1064, for ear rot and fumonisin contamination resistance without significantly lowering its yield potential, even with the use of a donor line with poor agronomic potential. Following one generation of selection on advanced backcross-derived lines, gains were observed for the primary trait of interest in advanced inbred generations. Following two generations of selection, we improved potential performance for ear rot resistance and reduced fumonisin accumulation in the 19 selected lines without significantly affecting important agronomic characteristics such as plant height, ear height, or flowering time compared to the recurrent parent, FR1064. The 19 selected lines were also significantly more resistant to ear rot under inoculated conditions than the FR1064 topcross without exhibiting significant reductions in topcross grain yield or other agronomic traits. Several individual lines were identified that were not statistically different from GE440 for ear rot or fumonisin content as inbreds or from the GE440 topcross for ear rot. These lines exhibited topcross yields comparable to the FR1064 topcross, although they were not competitive with commercial check yields. Thus, from a practical standpoint, the backcrossing method was effective at improving quantitative disease resistance in an elite commercial line using an unadapted donor parent. We also genotyped selected lines at DNA markers linked to ear rot and fumonisin resistance quantitative trait loci (QTL) identified in the BC1 generation of this cross to determine which QTL demonstrated allele frequency shifts due to selection.

Can in situ liquid SIMS provide enough signals for biology and energy research?

Yufan ZHOU,Yuanzhao DING,Jiachao YU,Xin HUA,James EVANS,Xiaofei YU,David LAO,Xiaoying YU,Zihua ZHU 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Polar aprotic solvent-water mixture as the medium for catalytic production of hydroxymethylfurfural (HMF) from bread waste

Yu, Iris K.M.,Tsang, Daniel C.W.,Chen, Season S.,Wang, Lei,Hunt, Andrew J.,Sherwood, James,De Oliveira Vigier, Karine,Jé,rô,me, Franç,ois,Ok, Yong Sik,Poon, Chi Sun Elsevier 2017 Bioresource technology Vol.245 No.1

<P><B>Abstract</B></P> <P>Valorisation of bread waste for hydroxymethylfurfural (HMF) synthesis was examined in dimethyl sulfoxide (DMSO)-, tetrahydrofuran (THF)-, acetonitrile (ACN)-, and acetone-water (1:1v/v), under heating at 140°C with SnCl<SUB>4</SUB> as the catalyst. The overall rate of the process was the fastest in ACN/H<SUB>2</SUB>O and acetone/H<SUB>2</SUB>O, followed by DMSO/H<SUB>2</SUB>O and THF/H<SUB>2</SUB>O due to the rate-limiting glucose isomerisation. However, the formation of levulinic acid (via rehydration) and humins (via polymerisation) was more significant in ACN/H<SUB>2</SUB>O and acetone/H<SUB>2</SUB>O. The constant HMF maxima (26–27mol%) in ACN/H<SUB>2</SUB>O, acetone/H<SUB>2</SUB>O, and DMSO/H<SUB>2</SUB>O indicated that the rates of desirable reactions (starch hydrolysis, glucose isomerisation, and fructose dehydration) relative to undesirable pathways (HMF rehydration and polymerisation) were comparable among these mediums. They also demonstrated higher selectivity towards HMF production over the side reactions than THF/H<SUB>2</SUB>O. This study differentiated the effects of polar aprotic solvent-water mediums on simultaneous pathways during biomass conversion.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bread waste was valorised for the synthesis of HMF, with yields of 26–27mol%. </LI> <LI> Fastest HMF production took place in ACN/H<SUB>2</SUB>O and acetonitrile/H<SUB>2</SUB>O systems. </LI> <LI> Slow glucose isomerization hindered HMF formation in DMSO/H<SUB>2</SUB>O and THF/H<SUB>2</SUB>O. </LI> <LI> Similar HMF selectivity was achieved in ACN/H<SUB>2</SUB>O, acetonitrile/H<SUB>2</SUB>O, and DMSO/H<SUB>2</SUB>O. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Eye Globe Abnormalities on MR and CT in Adults: An Anatomical Approach

James Thomas Patrick Decourcy Hallinan,Premilla Pillay,Lilian Hui Li Koh,Kong Yong Goh,Wai-Yung Yu 대한영상의학회 2016 Korean Journal of Radiology Vol.17 No.5

Eye globe abnormalities can be readily detected on dedicated and non-dedicated CT and MR studies. A primary understanding of the globe anatomy is key to characterising both traumatic and non-traumatic globe abnormalities. The globe consists of three primary layers: the sclera (outer), uvea (middle), and retina (inner layer). The various pathological processes involving these layers are highlighted using case examples with fundoscopic correlation where appropriate. In the emergent setting, trauma can result in hemorrhage, retinal/choroidal detachment and globe rupture. Neoplasms and inflammatory/infective processes predominantly occur in the vascular middle layer. The radiologist has an important role in primary diagnosis contributing to appropriate ophthalmology referral, thereby preventing devastating consequences such as vision loss.

The mRNA and Protein Levels of Tubulin and β-Actin Are Greatly Reduced in the Proximal Duodenum of Mice Relative to the Rest of the Small Intestines

Yu, Sungsook,Hwang, Hyekyung E.,Yun, Nakhyeon,Goldenring, James R.,Nam, Ki Taek Springer-Verlag 2015 Digestive diseases and sciences Vol.60 No.9

The Clear Water Pavilion

YU CHIO-O,Suh Ji-moon(번역자),James Wade(번역자) The Academy of Korean Studies 1975 Korea Journal Vol.15 No.8

Types of urbanization and economic growth

James Gross,Yu Ouyang 서울시립대학교 도시과학연구원 2021 도시과학국제저널 Vol.25 No.1

What is the relationship between urbanization and economic growth? Though many scholars have long documented the impact of urbanization on economic growth, others find no relationship has been established between rates of urbanization and rates of growth. While urbanization has typically been theorized as the product of a Harris-Todaro push-and-pull framework that encourages migration to urban areas for economic opportunity, recent works indicate that growth in urban areas stems from several distinct mechanisms. By re- conceptualizing urbanization as resulting from two distinct mechanisms – natural increase and residual increase, respectively – we examine the impact of types of urbanization on economic growth. We find that while urban residual increase is corelated to economic growth, urbanization due to natural births and deaths is not. The results contribute to existing literature by providing an important insight into the factors behind economic growth and the effects of urbanization.