• Journal of Pharmaceutical Investigation
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• v.32 no.4
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• pp.277-284
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• 2002

Lansoprazole, pharmaceutics for acid-related diseases, is unstable in low pH environments and generally coated with enteric polymer to obtain gastroresistance in stomach. Because its storage stability is influenced by acidic substitutes of enteric polymer, alkaline chemicals wεre generally addεd to dosage form as a stabilizer. In this experience, we coated lansoprazole bead with sodium alginate and evaluated the effect of bead size and sodium alginate coating on the storage stability and dissolution profile of lansoprazole. Sodium alginate solution containing lansoprazole was sprayed as a droplet into 3% (w/v) $CaCl_2$ solution and the resultant bead was coated with starch, sodium alginate, and hydroxypropyl methylcellulose phthalate. The content of lansoprazole granule not coated with sodium alginate decreased to 57.96% of initial content when stored at a severe condition for 4 weeks, but that of lansoprazole granule coated with sodium alginate before enteric coating decreased little and as the thickness of sodium alginate film increased, the content of bead didn't decreased for 4 weeks. Sodium alginate film also improved the gastroresistance without much influencing the maximum dissolution rate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.3
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• pp.224-228
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• 2012

We have developed new materials that lead to methyl meth acrylate monomer and styrene monomer to using polymerization method. The materials have a powder form and show liquid behavior. We call the "Electronic Bead". An our experiment, a positive-charged particle has $TiO_2$, polymer and CCA(-), while a negative-charged particle consists of carbon black, polymer and CCA(+). The charged particles have electrical characteristic of white -10 uC/g and black 10 uC/g, respectively. Also, these particles have good fluidity by additive of nano-sized silica. Using these materials, we demonstrated prototype displays that have $320{\times}320$ array of pixels and 6-in-diagonal viewable image size, driven by passive-matrix addressing. The reflectivity shows about 30% even though our experiment is at the beginning point. Also, the panel has contrast ratio 6:1. We think there are many chances to improve reflectivity through modifying components of particle resin, mixture ratio of each particle, panel structure and so on.

• Polymer(Korea)
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• v.26 no.5
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• pp.575-581
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• 2002

Heterogeneous ion exchange membranes were prepared by mixing polyethylene as matrix with bead and fibrous anionic ion exchangers at different mixing ratio. Generally, ion exchange capacities were increased with increasing the ratio of the fibrous ion exchanger content. The highest ion exchange capacity of the membrane was 1.86 meq/g at 30wt% IXF (ion exchange fiber) in the membrane. The water uptake, fixed ion concentration, and ion transport number of the membrane increased with increasing the content of the fibrous ion exchanger. However, the electrical resistivity of the membrane was decreased with increasing the content of the fibrous ion exchanger. The lowest electrical resistivity of 5$\Omega$/$\textrm{cm}^2$ was observed at 30 wt%of IXF.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.48-56
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• 2018

A potassium copper hexacyanoferrate (KCuHCF) embedded magnetic hydrogel bead (HCF-Mbead) was synthesized via a facile double crosslinking methods of $Fe^{3+}$ ionic binding and freeze-thaw for effective $Cs^+$ removal. The HCF-Mbead had a hierarchical porous structure facilitating fast access of $Cs^+$ ions to embedded active sites. The adsorbent showed enhanced $Cs^+$ removal properties in terms of capacity (69.2 mg/g), selectivity ($K_d=4{\times}10^4mL/g$, 1 ppm $Cs^+$ in seawater) and stability (>99.5% removal in pH 3~11) with rapid magnetic separation. This study further opens the possibility to develop an efficient material that links the integration of adsorption and recovery.

• Journal of Marine Bioscience and Biotechnology
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• v.12 no.2
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• pp.81-90
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• 2020

Sialic acid, which is contained in about 60-160 mg/kg in the edible bird's nest (EBN), is known to facilitate in the proper formation of synapses and improve memory function. The objective of this study is to extract effectively the sialic acid from edible bird's nest using affinity bead technology (ABT). After preparing the non-polar polymeric bead "KJM-278-28A" having a porous network structure, and then desorbed sialic acid was concentrated and dried. The analysis of the physicochemical properties of bead "KJM-278-28A" showed that the particle size was 400-700 ㎛, the moisture holding capacity was 67-70%, the surface area (BET) was 705-900 ㎡/g, and the average pore diameter 70-87 Å. The adsorption capacity of the bead "KJM-278-28A" for sialic acid was shown a strong physical force to bind sialic acid to the bead surface of 400 mg/L. In addition, as a result of analyzing the adsorption and desorption effects of sialic acid on water, ethanol, and 10% ethanol on the bead, it was confirmed that desorption effectively occurs from the beads when only ethanol is used. As a result of HPLC measurement of the separated sialic acid solution, a total of four sialic acid peaks of N-acetyl-neuraminic acid (Neu5Ac), α,β-anomer of Neu5Ac and N-glycoly-neuraminic acid were identified. Through these results, it was confirmed that it is possible to separate sialic acid from EBN extract with efficient and high yield when using ABT.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2426-2430
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• 2007

Dissipative particle dynamics simulations of bead-spring dumbbell models under microchannel flow were performed and the effects of the deformation on their migration behavior were discussed. Dumbbells were found to migrate toward the walls or the channel center depending on the stiffness. Stiff dumbbells migrated toward the walls. In any cases, the dumbbells were found to have a stronger tendency to move toward the channel center in more deformable conditions.

• Korea-Australia Rheology Journal
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• v.12 no.2
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• pp.107-117
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• 2000

Prediction of the product shape in sheet casting process is performed from the numerical simulation. A three-dimensional finite element method is used to investigate the flow behavior and to examine the effects of processing conditions on the sheet produced. Effects of inertia, gravity, surface tension and non-Newtonian viscosity on the thickness profile of the sheet are considered since the edge bead and the flow patterns in the chill roll region have great influence on the quality of the products. In the numerical simulation with free surface flows, the spine method is adopted to update the free surface, and the force-free boundary condition is imposed along the take-up plane to avoid severe singularity problems existing at the take-up plane. From the numerical results of steady isothermal flows of a generalized Newtonian fluid, it is shown that the draw ratio plays a major role in predicting the shape of the final sheet produced and the surface tension has considerable effect on the bead thickness ratio and the bead width fraction, while shear-thinning and/or tension-thickening viscosity affect the degree of neck-in.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.255-256
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• 2005

• Macromolecular Research
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• v.13 no.4
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• pp.285-292
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• 2005

We developed alginate beads loaded with transforming growth $factor-{\beta}_{1}(TGF-{\beta}_{1})$ to examine the possible application of the scaffold and cytokine carrier in tissue engineering. In this study, bone marrow stromal cells (BMSCs) and $TGF{\beta}_{1}$ were uniformly encapsulated in the alginate beads and then cultured in vitro. The cell morphology and shape of the alginate beads were observed using inverted microscope, scanning electron microscope (SEM), histological staining and RT-PCR to confirm chondrogenic differentiation. The amount of the $TGF{\beta}_{1}$ released from the $TGF-{\beta}_{1}$ loaded alginate beads was analyzed for 28 days in vitro in a phosphate buffered saline (pH 7.4) at $37^{\circ}C$. We observed the release profile of $TGF-{\beta}_{1}$ from $TGF-{\beta}_{1}$ loaded alginate beads with a sustained release pattern for 35 days. Microscopic observation showed the open cell pore structure and abundant cells with a round morphology in the alginate beads. In addition, histology and RT-PCR results revealed the evidence of chondrogenic differentiation in the beads. In conclusion, these results confirmed that $TGF-{\beta}_{1}$ loaded alginate beads provide excellent conditions for chondrogenic differentiation.

• Polymer(Korea)
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• v.38 no.6
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• pp.760-766
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• 2014

Bead type super-absorbent resins to be used for release-control were prepared by modification of the inverse suspension polymerization, and their physical properties were characterized. Acrylic acid and acrylamide were used as monomers, and N,N-methylenebisacrylamide was used as crosslinker, controlling the viscosity of monomer solution by adding hydroxyethylcellulose (HEC). SEM studies of the synthesized beads verified that the bead surfaces had many pores with their diameters of several tens nm. The bead sizes were in the range of $500{\sim}3000{\mu}m$, depending on the viscosity of the monomer solution. Both absorbent amount and absorbent rate of the beads were inversely proportional to the bead size, and the maximum water absorbent amount of 1 g beads was determined to be ca. 170~200 g for 5 hrs. The absorbent rate was also dependent on pH change of the aqueous solution, exhibiting the maximum rate in pH ranging from 5 to 11. The absorbent rate decreased as the concentration of salt (NaCl and $MgCl_2$) or ethanol and ethylene glycol increased. Release time of the water absorbed into the bead resins was 700 hrs, confirming the usefulness of the resin for the good release-control materials.