Jong-min Lim - Academia.edu (original) (raw)
Papers by Jong-min Lim
Journal of Plant Biology, 2006
The dehydrins (DHN) are a family of late embryo abundant (LEA D-11) proteins, which accumulate du... more The dehydrins (DHN) are a family of late embryo abundant (LEA D-11) proteins, which accumulate during the late stage of seed development or under low temperature or water deficient conditions. They are believed to play a protective role in freezing and drought tolerance. The dehydrin genes exist as multi-gene families. Here, we have identified 9 unique dehydrin genes from Korean ginseng (Panax ginseng C.A. Meyer), a typical medicinal plant Among these,PgDhn1 andPgDhn2 encode for YSK3- and KS-type dehydrins, respectively, and are very abundant. Gene expression analyses revealed that the majority of thePgDhn gene transcripts are detected under cold, as well as dehydration conditions. The exceptions arePgDhn5 and PgDhn9—the former being unresponsive to cold treatment, and the latter exhibiting only seed-specific expression. We also identified an alternative transcript of thePgDhn2 gene that harbors an intron in its 3’-untranslated region. Our results may prove useful in further studies ofDhn genes, including investigations into the mechanisms underlying gene expression, the nature of their variations, and their physiological functions.
Journal of The American Chemical Society, 2005
Most of the colloidal clusters have been produced from oil-in-water emulsions with identical micr... more Most of the colloidal clusters have been produced from oil-in-water emulsions with identical microspheres dispersed in oil droplets. Here, we present new types of binary colloidal clusters from phaseinverted water-in-oil emulsions using various combinations of two different colloids with several size ratios: monodisperse silica or polystyrene microspheres for larger particles and silica or titania nanoparticles for smaller particles. Obviously, a better understanding of how finite groups of different colloids self-organize in a confined geometry may help us control the structure of matter at multiple length scales. In addition, since aqueous dispersions have much better phase stability, we could produce much more diverse colloidal materials from water-in-oil emulsions rather than from oil-in-water emulsions. Interestingly, the configurations of the large microspheres were not changed by the presence of the small particles. However, the arrangement of the smaller particles was strongly dependent on the nature of the interparticle interactions. The experimentally observed structural evolutions were consistent with the numerical simulations calculated using Surface Evolver. These clusters with nonisotropic structures can be used as building blocks for novel colloidal structures with unusual properties or by themselves as light scatterers, diffusers, and complex adaptive matter exhibiting emergent behavior.
Langmuir, 2007
Superhydrophobic nanofiber films were created from electrospun nanofibers with undulated surfaces... more Superhydrophobic nanofiber films were created from electrospun nanofibers with undulated surfaces at multiple scales in micrometers and nanometers. The electrospun nanofibers were produced out of aqueous solutions which contained water-soluble polymers and different colloids: monodisperse silica or polystyrene microspheres for larger particles and monodisperse silica nanoparticles for smaller particles. Various types of fibrous films were produced depending on the properties of the dispersing medium, the effects of additives, and the compositions of the bidisperse colloids. When polystyrene microspheres were used as sacrificial templates, macropores were left behind in the nanofibers during the removal of polystyrene microspheres by calcination. The nonwoven films of electrospun nanofibers, which were decorated with silica microspheres or macropores, could be continuously produced with considerable ease under a relatively wide range of operating conditions. The surface properties of the films were characterized by contact angle measurement and an X-ray photoelectron spectrometer. Through the surface modification of the electrospun nanofibers with fluorinated silane coupling agents, superhydrophobic surfaces with low sliding angles were successfully prepared. * Corresponding authors.
Lab on A Chip, 2008
We have demonstrated fluorescent liquid-core/air-cladding (LA) waveguides suitable for use as int... more We have demonstrated fluorescent liquid-core/air-cladding (LA) waveguides suitable for use as integrated optofluidic light sources. These waveguides were fabricated by conventional soft lithography using poly(dimethylsiloxane) (PDMS). Two-phase stratified flows of air and ethylene glycol with fluorescent dye were generated along the PDMS channel. Compared to the liquid-core/liquid-cladding (L(2)) waveguide, the larger refractive index contrast of the LA waveguide resulted in stronger optical confinement. Specifically, the larger refractive index contrast led to experimentally achievable captured fractions (the amount of light to be coupled into the liquid core) as high as 22.8% and the measured propagation losses as low as 0.14 dB cm(-1). Furthermore, in our LA waveguides, diffusional mixing of the core and cladding fluids did not occur and the size of the core stream could be reversibly tuned simply by adjusting the flow rates of the two contiguous phases.
Langmuir, 2006
Electrospun nanofibers were used as confining geometries for fabricating 1-D colloidal assemblies... more Electrospun nanofibers were used as confining geometries for fabricating 1-D colloidal assemblies. Silica particles dispersed in several different polymer solutions were cast into nanofibers by an electrospinning process. The silica particle configurations were examined in terms of the size ratio of silica particles to nanofibers and the properties of the dispersing medium. As the electrospun fiber was extended highly, the silica particles dispersed in the polymer solution began to assemble spontaneously into a pearl-necklace structure. We also demonstrated the alignment of 1-D silica assemblies using a designed configuration of collector electrodes.
Journal of Plant Biology, 2006
The dehydrins (DHN) are a family of late embryo abundant (LEA D-11) proteins, which accumulate du... more The dehydrins (DHN) are a family of late embryo abundant (LEA D-11) proteins, which accumulate during the late stage of seed development or under low temperature or water deficient conditions. They are believed to play a protective role in freezing and drought tolerance. The dehydrin genes exist as multi-gene families. Here, we have identified 9 unique dehydrin genes from Korean ginseng (Panax ginseng C.A. Meyer), a typical medicinal plant Among these,PgDhn1 andPgDhn2 encode for YSK3- and KS-type dehydrins, respectively, and are very abundant. Gene expression analyses revealed that the majority of thePgDhn gene transcripts are detected under cold, as well as dehydration conditions. The exceptions arePgDhn5 and PgDhn9—the former being unresponsive to cold treatment, and the latter exhibiting only seed-specific expression. We also identified an alternative transcript of thePgDhn2 gene that harbors an intron in its 3’-untranslated region. Our results may prove useful in further studies ofDhn genes, including investigations into the mechanisms underlying gene expression, the nature of their variations, and their physiological functions.
Journal of The American Chemical Society, 2005
Most of the colloidal clusters have been produced from oil-in-water emulsions with identical micr... more Most of the colloidal clusters have been produced from oil-in-water emulsions with identical microspheres dispersed in oil droplets. Here, we present new types of binary colloidal clusters from phaseinverted water-in-oil emulsions using various combinations of two different colloids with several size ratios: monodisperse silica or polystyrene microspheres for larger particles and silica or titania nanoparticles for smaller particles. Obviously, a better understanding of how finite groups of different colloids self-organize in a confined geometry may help us control the structure of matter at multiple length scales. In addition, since aqueous dispersions have much better phase stability, we could produce much more diverse colloidal materials from water-in-oil emulsions rather than from oil-in-water emulsions. Interestingly, the configurations of the large microspheres were not changed by the presence of the small particles. However, the arrangement of the smaller particles was strongly dependent on the nature of the interparticle interactions. The experimentally observed structural evolutions were consistent with the numerical simulations calculated using Surface Evolver. These clusters with nonisotropic structures can be used as building blocks for novel colloidal structures with unusual properties or by themselves as light scatterers, diffusers, and complex adaptive matter exhibiting emergent behavior.
Langmuir, 2007
Superhydrophobic nanofiber films were created from electrospun nanofibers with undulated surfaces... more Superhydrophobic nanofiber films were created from electrospun nanofibers with undulated surfaces at multiple scales in micrometers and nanometers. The electrospun nanofibers were produced out of aqueous solutions which contained water-soluble polymers and different colloids: monodisperse silica or polystyrene microspheres for larger particles and monodisperse silica nanoparticles for smaller particles. Various types of fibrous films were produced depending on the properties of the dispersing medium, the effects of additives, and the compositions of the bidisperse colloids. When polystyrene microspheres were used as sacrificial templates, macropores were left behind in the nanofibers during the removal of polystyrene microspheres by calcination. The nonwoven films of electrospun nanofibers, which were decorated with silica microspheres or macropores, could be continuously produced with considerable ease under a relatively wide range of operating conditions. The surface properties of the films were characterized by contact angle measurement and an X-ray photoelectron spectrometer. Through the surface modification of the electrospun nanofibers with fluorinated silane coupling agents, superhydrophobic surfaces with low sliding angles were successfully prepared. * Corresponding authors.
Lab on A Chip, 2008
We have demonstrated fluorescent liquid-core/air-cladding (LA) waveguides suitable for use as int... more We have demonstrated fluorescent liquid-core/air-cladding (LA) waveguides suitable for use as integrated optofluidic light sources. These waveguides were fabricated by conventional soft lithography using poly(dimethylsiloxane) (PDMS). Two-phase stratified flows of air and ethylene glycol with fluorescent dye were generated along the PDMS channel. Compared to the liquid-core/liquid-cladding (L(2)) waveguide, the larger refractive index contrast of the LA waveguide resulted in stronger optical confinement. Specifically, the larger refractive index contrast led to experimentally achievable captured fractions (the amount of light to be coupled into the liquid core) as high as 22.8% and the measured propagation losses as low as 0.14 dB cm(-1). Furthermore, in our LA waveguides, diffusional mixing of the core and cladding fluids did not occur and the size of the core stream could be reversibly tuned simply by adjusting the flow rates of the two contiguous phases.
Langmuir, 2006
Electrospun nanofibers were used as confining geometries for fabricating 1-D colloidal assemblies... more Electrospun nanofibers were used as confining geometries for fabricating 1-D colloidal assemblies. Silica particles dispersed in several different polymer solutions were cast into nanofibers by an electrospinning process. The silica particle configurations were examined in terms of the size ratio of silica particles to nanofibers and the properties of the dispersing medium. As the electrospun fiber was extended highly, the silica particles dispersed in the polymer solution began to assemble spontaneously into a pearl-necklace structure. We also demonstrated the alignment of 1-D silica assemblies using a designed configuration of collector electrodes.