• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.376-376
• /
• 2016

Poly(ethylene oxide) (PEO)/functionalized bacterial cellulose nanowhiskers (f-BCNW) (0.1 wt%) composite nanofibers were fabricated by electrospinning process and the thermomechanical properties were significantly enhanced more than the PEO and PEO/bacterial cellulose nanowhiskers (BCNW) (0.1 wt%) composite nanofibers. The functionalization of BCNW (f-BCNW) was performed by microwave plasma treatment for effects of nitrogen functionalization of chemically-driven BCNW. The N-containing functional groups of f-BCNW enhanced chemical bonding between the hydroxyl groups of the polymer chains in the PEO matrix and diameter size of PEO/f-BCNW (0.1 wt%) composite nanofibers were decreased more than PEO and PEO/BCNW (0.1 wt%) composite nanofibers on the same concentration. The strong interfacial interactions between the f-BCNW nanofillers and polymer matrix were improved the thermomechanical properties such as crystallization temperature, weight loss and glass transition temperature (Tg) compared to PEO and PEO/BCNW composites nanofibers. The results demonstrated that N2 plasma treatment of BCNW is very useful in improving thermal stability for bio-applications.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제10권4호
• /
• pp.372-377
• /
• 2005

Aralia elata is an edible mountain vegetable. Angiogenesis, the formation of new blood vessels, is a process involving migration, proliferation and cell differentiation, as well as the formation of new capillary structures. Matrix metalloproteinases (MMPs) plays an important role in angiogenesis. The development of a functional vascular system requires a variety of growth factors, their receptors, and intracellular signals. This study examines the effects of water extracts from: (i) A. elata root bark (Aralia extracts); (ii) a combination of Aralia extracts and fibroblast growth factors (FGF-2) on cultured porcine coronary artery endothelial cells (PCAECs). Aralia extracts induced the migration of PCAECs, which was inhibited by MMPs inhibitors. Combining Aralia extracts and FGF-2 enhanced the migration and the secretion of MMP-2 and MMP­9 from PCAECs. We postulated that the Aralia extracts, which induced migrating activity in PCAECs, may be accomplished by increased secretion levels of MMP-2 and MMP-9.

• 전기학회논문지
• /
• 제66권5호
• /
• pp.806-811
• /
• 2017

This paper considers the delay-dependent stability of linear systems with a time-varying delay in the frame work of Lyapunov-Krasovskii functional(LKF) approach. In this approach, an integral inequality is essential to estimate the upper bound of time-derivative of LKF, and a less conservative one is needed to get a less conservative stability result. In this paper, based on free weighting matrices, an improved integral inequality encompassing well-known results is proposed and then a stability result in the form of linear matrix inequality is derived based on an augmented LKF. Finally, two well-known numerical examples are given to demonstrate the usefulness of the proposed result.

• Journal of Pharmaceutical Investigation
• /
• 제35권3호
• /
• pp.173-177
• /
• 2005

Addition of 30% propylene glycol was required to maintain sink condition in the evaluation of percutaneous absorption of estradiol and norethindrone acetate. The permeability of estradiol was higher in silicone and SIS adhesives. However, estradiol was crystallized in silicone, SIS, and SBS adhesive matrix. The permeability ratio of estradiol or norethindrone acetate from acrylic pressure sensitive adhesives varied widely depending on the functional group of the acrylic adhesives. PEO grafting to acrylic adhesive seemed to change physicochemical property of acrylic adhesive and increased the permeability of estradiol and norethindrone acetate significantly. On the contrary, highly cross-linked enhancer compatible acrylic adhesive decreased the permeability of both estradiol and norethindrone acetate. $Span^{\circledR}$ 20 provided the highest enhancing effect on the permeability of both estradiol and norethindrone acetate followed by oleic acid and $Crovol^{\circledR}$ EP40. The permeability of the drugs from the developed system was comparable to that from commercial $Combitran^{\circledR}$, although significantly lower amount of estradiol and norethindrone acetate were loaded in the developed system.

• Macromolecular Research
• /
• 제15권6호
• /
• pp.581-586
• /
• 2007

Cast DNA/polyethyleneimine (PEI) blend membranes containing different amounts of DNA were prepared using acid-base interaction and characterized with the aim of understanding the polymer electrolyte membrane properties. Two different molecular weights of PEI were used to provide the mechanical strength, while DNA, a polyelectrolyte, was used for the proton transport channel. Proton conductivity was observed for the DNA/PEI membrane and reached approximately $3.0{\times}10^{-3}S/cm$ for a DNA loading of 16 wt% at $80^{\circ}C$. The proton transport phenomena of the DNA/PEI complexes were investigated in terms of the complexation energy using the density functional theory method. In the case of DNA/PEI, a cisoid-type complex was more favorable for both the formation of the complex and the dissociation of hydrogen from the phosphate. Since the main requirement for proton transport in the polymer matrix is to dissociate the hydrogen from its ionic sites, this suggests the significant role played by the basicity of the matrix.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권18호
• /
• pp.8047-8052
• /
• 2016

Proteases are important molecules that are involved in many key physiological processes. Protease signaling pathways are strictly controlled, and disorders in protease activity can result in pathological changes such as cardiovascular and inflammatory diseases, cancer and neurological disorders. Many proteases have been associated with increasing tumor metastasis in various human cancers, suggesting important functional roles in the metastatic process because of their ability to degrade the extracellular matrix barrier. Proteases are also capable of cleaving non-extracellular matrix molecules. Inhibitors of proteases to some extent can reduce invasion and metastasis of cancer cells, and slow down cancer progression. In this review, we focus on the role of a few proteases and their inhibitors in tumors as a basis for cancer prognostication and therapy.

• Genomics & Informatics
• /
• 제1권1호
• /
• pp.20-24
• /
• 2003

The analysis of DNA microarry data is one of the most important things for functional genomics research. The matrix representation of microarray data and its successive 'optimal' incisional hyperplanes is a useful platform for developing optimization algorithms to determine the optimal partitioning of pairwise proximity matrix representing completely connected and weighted graph. We developed Deterministic Annealing (DA) approach to determine the successive optimal binary partitioning. DA algorithm demonstrated good performance with the ability to find the 'globally optimal' binary partitions. In addition, the objects that have not been clustered at small non­zero temperature, are considered to be very sensitive to even small randomness, and can be used to estimate the reliability of the clustering.

• 전기학회논문지
• /
• 제64권1호
• /
• pp.121-127
• /
• 2015

This paper considers the problem of sampled-data control for continuous linear parameter varying (LPV) systems. It is assumed that the sampling periods are arbitrarily varying but bounded. Based on the input delay approach, the sampled-data control LPV system is transformed into a continuous time-delay LPV system. Some less conservative stabilization results represented by LMI (Linear Matrix Inequality) are obtained by using the Lyapunov-Krasovskii functional method and the reciprocally combination approach. The proposed method for the designed gain matrix should guarantee asymptotic stability and a specified level of performance on the closed-loop hybrid system. Numerical examples are presented to demonstrate the effectiveness and the improvement of the proposed method.

• 대한의생명과학회지
• /
• 제12권3호
• /
• pp.185-190
• /
• 2006

Lysyl oxidase (LOX) catalyzes the lysine-derived cross-links of fibrillar collagens and elastin in the extracellular matrix. Recent molecular cloning has revealed existence of a LOX family consisting of LOX and four lysyl oxidase-like proteins (LOXL, LOXL2, LOXL3 and LOXL4). Pathological conditions associated with impaired LOX activity in several heritable and acquired disorders lead to severe structural and functional abnormalities of cardiovascular tissues, such as occlusion of coronary arteries and aneurysms, suggesting an essential role for the LOX family proteins in the maintenance of the cardiovascular system. However, the specific roles of the lysyl oxidase-like proteins in normal and pathological conditions of the cardiovascular tissues have not been established yet. Here, I report that LOXL3, a novel member of the LOX family, is predominantly expressed in the aorta, with an amine oxidase activity toward collagen and elastin, suggesting an essential role of LOXL3 in the development and maintenance of the aorta.

• 반도체디스플레이기술학회지
• /
• 제16권1호
• /
• pp.52-58
• /
• 2017

Graphene oxide (GO)/carboxylated styrene-butadiene rubber (XSBR) nanocomposites with various contents of GO were prepared by a latex compounding method. It has been confirmed that the functional groups of GO and the hydrogen bonds between GO and XSBR are existed. It can be seen that the scorch time ($t_{s2}$), which is the measurement of incipient vulcanization of rubber, showed a delay after the addition of GO. Field emission scanning electron microscopy was employed to confirm the uniform dispersion of filler in the matrix. Indeed, with increasing fillers loading, the torque, tensile strength, thermal stability and crosslink density of obtained nanocomposites were improved. These results were correlated to the better dispersion of fillers through the rubber matrix.