• Membrane Journal
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• v.15 no.4
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• pp.281-288
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• 2005

The hyaluronic acid (HA) with excellent biocompatibility can be combined with lactide, the ester dimer of polylactide, with good biodegradability to produce biocompatible materials applicable to drug delivery system. By freeze drying method, HA and lactide were crosslinked with crosslinking agent, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide. Degree of lactide and EDC reaction was determined by the analysis of nuclear magnetic resonance (NMR) spectroscopy. The degree of lactide and EDC reaction increased and swelling ratio decreased as the mole ratio of lactide to HA or crosslinking agent concentration increased or reaction temperature decreased. The drug release experiment result from membranes having different degree of lactide reaction showed that drug release rate reduced in proportion to the degree of lactide reaction. The drug release experiment result from drugs having different hyrodphobicity showed that the more hydrophobic drug was released more slowly.

• Polymer(Korea)
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• v.37 no.6
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• pp.784-793
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• 2013

A two-step method for obtaining poly(N-isopropylacrylamide) (PNIPAAm) from poly(acrylonitrile) (PAN) was investigated in order to find a feasibility of imparting thermo-responsive property onto textile fiber materials. PAN was converted to poly(acrylic acid) (PAA) by hydrolysis at a first-step, and then PAA was converted to PNIPAAm at a second step via an amidation reaction of PAA with isopropylamine (IPA) in DMF medium using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) as catalysts. High content of carboxylic groups at the first step was obtained by the successive alkaline and acid hydrolysis of PAN. The degree of conversion of PAA to PNIPAAm at the second step was dependent on the amount of catalysts EDC and NHS. PNIPAAm converted from PAA through amidation reaction showed a lower critical solution temperature (LCST) behavior when the conversion was higher than about 53%.

• Nuclear Engineering and Technology
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• v.50 no.2
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• pp.246-252
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• 2018

A series of simulated reactivity-initiated accident (RIA) tests on irradiated fully recrystallized boiling water reactor Zircaloy-2 cladding has been performed by means of the expansion-due-to-compression (EDC) test method. The EDC method reproduces fuel pellet-clad mechanical interaction (PCMI) conditions for the cladding during RIA transients with respect to temperature and loading rates by out-of-pile mechanical testing. The tested materials had a large variation in burnup and hydrogen content (up to 907 wppm). The results of the EDC tests showed variation in the PCMI resistance of claddings with similar burnup and hydrogen content, making it difficult to clearly identify ductile-to-brittle transition temperatures. The EDC-tested samples of the present and previous work were investigated by light optical and scanning electron microscopy to study the influence of factors such as azimuthal variation of the Zr-hydrides and the presence of hydride rims and radially oriented hydrides. Two main characteristics were identified in samples with low ductility with respect to hydrogen content and test temperature: hydride rims and radial hydrides at the cladding outer surface. Crack propagation and failure modes were also studied, showing two general modes of crack propagation depending on distribution and amount of radially oriented hydrides. It was concluded that the PCMI resistance of irradiated cladding under normal conditions with homogenously distributed circumferential hydrides is high, with good margin to the RIA failure limits. To further improve safety, focus should be on conditions causing nonfavorable hydride distribution, such as hydride reorientation and formation of hydride blisters at the cladding outer surface.

• Development and Reproduction
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• v.2 no.2
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• pp.115-133
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• 1998

Recently public concerns about the endocrine disrupting chemicals (EDC) have resulted in the increased legistrative and regulatory attentions in many countries. Endocrine disrupter is an exogeneous chemical interfering the synthesis, transport binding, action or elimination of natural hormones in the body, which are responsible for the maintenance of homeostasis, reproduction, development and/or behavior. Reported possible harmful effects on human and animal lives, possible developmental anomalities, reproductive malfunctions and behaviors, and the ways of EDC accumulation in animal kingdom are reviewed. The current scientific papers and knowledges on the global contamination of EDCs demonstrates the conclusive data that EDCs have the potentials to cause the calamitous extermination of human and animal species by the global contamination.

• The Korean Journal of Zoology
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• v.39 no.4
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• pp.393-399
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• 1996

A zero-Iength croessinking procedure for studying protein-protein interactlons in preinitiation complex has heen developed. Preinltiadon complexes were assembled with immobilized DNA templates coupled to metal beads. Pudfied complexes were dIrectly crosslinked by 1-ethyl-3.(3-dimethylaminopropyl)carbodlimide (EDC). The reaction was stopped by addition of $\beta$-mercaptoethanol, and the complexes were isolated from EDC immedIately. An appllcatlion of this method with a preinltlation complex assembled with TBP, TFIIB, and GAL4-AH demonstrated that ThP dIrectly interacts with GAL4-AH and TFIIB in the prelnitlatlon complex. However, croeslinked produd between GAL4-AH and ThilB was not observed. These resutts lndlcate that GAL4-AH does not stably Interact with TFIIB In the GAL4-AH-TFIIB-TBP-DNA prelnitlatlon complex.

• Journal of Environmental Health Sciences
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• v.44 no.1
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• pp.76-89
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• 2018

Background: Exposure to endocrine disrupting chemicals (EDCs) has been considered one of the main causes of a range of endocrine diseases in modern society. An EDC priority list considering exposure, toxicity, and societal concern should be established for EDC management. Methods: The chemical ranking and scoring (CRS) system for EDCs was based on exposure, toxicity,and societal concern. The exposure score system was based on usage, circulation volume, bioaccumulation, and detection in consumer products. The toxicity score system was based on carcinogenicity and reproductive and developmental toxicity. The societal concern score system was based on domestic or international regulations and mass media reports. Results: A total of 165 EDCs were considered in the CRS system. The top-five priority EDCs were Bis(2-ethylhexyl) phthalate (DEHP), Benzene, Bisphenol A, Dibutyl phthalate (DBP) and Trichloroethylene. Phthalates, bisphenols and parabens were identified as priority chemical groups. Conclusion: We developed a CRS system for EDCs to identify priority EDCs for management. This will be a foundation to provide an EDC management plan based on scientific decision-making.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.4
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• pp.342-347
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• 2022

In-situ analyzation and detection of real-time chemical reactions can be a significant part in interpreting the underlying mechanism in very reactive chemical reactions. To do this, first we have designed a microfluidic device (MFD) pattern for observation of synthesis of hierarchical nanostructures based on graphene oxide (GO), conjugating the well-known coupling reaction by which the solution of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-mediated coupling is enhanced in the presence of n-hydroxysuccinimide (NHS) to make amide bonding, hereafter called as the EDC coupling. Then, we have manufactured microfluidic devices with multiple tens of micrometer-sized channels that can circulate those nanomaterials to be chemically reacted in the channels. These microfluidic devices were made by negative photo lithography and soft lithography. We showed the possibility of using Raman spectroscopy to reveal the basic mechanism of the energy storage applications.

• Development and Reproduction
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• v.26 no.4
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• pp.175-182
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• 2022

Previous studies, including our own, indicate that distinct morphological changes in rodent adrenal cortex could be induced by exposure of endocrine disrupting chemicals (EDC). In the present study, we conducted histological analyses of adrenocortical substructure using a nonylphenol-treated F1 rat model. The adrenal weight of NP-5000 group was significantly declined in female rats (p<0.001), while the adrenal weights of NP-treated groups were not significantly changed in male rats. The thickness of zona glomerulosa layers of female rats in NP-5000 group was significantly declined (p<0.001) but zona fasciculata layers were not changed. The zona reticularis layers of NP-treated group were significantly thinner than those of control group (NP-50, p<0.05; NP-5000, p<0.01). In male adrenal glands, there was no significant change of zona glomerulosa layers in NP-treated groups while the thickness of zona fasciculata in NP-5000 group was significantly decreased (p<0.01). Like female rats, the thickness of zona reticularis in NP-treated groups was significantly decreased (NP-50, p<0.001; NP-5000, p<0.05). Present study demonstrated that the adrenal histology could be altered by low-dose NP exposure in F1 rats, and the effect might be sexually dimorphic. Further study will be helpful for understanding possible adrenal pathophysiology induced by EDC exposure, and EDC-related sexually dimorphic phenomena in rodent adrenals.

• Journal of Chest Surgery
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• v.46 no.1
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• pp.1-13
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• 2013

Background: Glutaraldehyde (GA) is a widely used cross-linking agent for improving mechanical properties and resistance to enzymatic degradation of collagenous tissue, but it has several drawbacks such as calcification and cytotoxicity. The aim of this study was to find the alternative effective cross-linking methods to GA. Materials and Methods: Bovine pericardium was processed with GA with ethanol+octanol and glycine detoxification, and polyethylene glycol (PG) space filler, dimethyl 3,3'-dithiobispropionimidate (DTBP), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) treatment, and the physical fixation of ultraviolet irradiation were done. The biologic material properties of variously treated pericardial tissues were assessed by biochemical, mechanical and histological tests. Treated pericardial tissues were also implanted subcutaneously or intramuscularly into the rabbit for 10 weeks to assess the xenoreactive antibody response of immunoglobulin G and M, their anti-calcification effect. Results: The biochemical and mechanical properties of EDC fixed pericardial tissues were comparable to the GA fixed tissue. The cytotoxicity was lowest in space filler treated GA fixed group. In rabbit subcutaneous or intramuscular implantation models, decellularization, space filler, EDC treatment group showed significantly lower calcium content than GA only and DTBP treatment group (p<0.05, analysis of variance). The titer of anti $Gal{\alpha}1-3Gal{\beta}1$-4GlcNAc-R antibodies did not change in the postimplantation serial enzyme-linked immunosorbent assay. Hematoxylin and eosin and von Kossa staining showed that decellularization, space filler, EDC, and ultraviolet treatment had less inflammatory cell infiltration and calcium deposits. Conclusion: The decellularization process, PG filler, and EDC treatments are good alternative cross-linking methods compared to GA only fixation and primary amine of DTBP treatment for cardiovascular xenograft preservation in terms of the collagen cross-linking stability and in vivo anti-calcification effects.

• Polymer(Korea)
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• v.33 no.2
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• pp.104-110
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• 2009

Demineralized boneparticle (DBP) has been widely used as and a powerful promoter of new bone growth. In this study, DBP sponges were chemically crosslinked and characterized for the potential application of tissue engineered scaffolds. The DBP sponges prepared by crosslinking with EDC. 0.1, 0.2 or 0.3% pepsin was applied to DBP dissolved in 3% (v/v) acetic acid aqueous solution for 48 hrs. The prepared sponges were crosslinked by 1, 5, 10, 50 or 100 mM of EDC solution concentration and then were lyophilized. The DBP sponges were characterized by SEM, FT-IR and DSC and analyzed in terms of their porosity and water absorption ability. The cellular viability and proliferation were assayed by MTT assay. Our investigation revealed that 0.2$\sim$0.3% of pepsin and 50$\sim$100 mM of EDC produced DBP sponges with good physical characteristics. In conclusion, DBP sponge prepared under these conditions is potentially useful for the applications of tissue construction.