• Biomolecules & Therapeutics
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• v.10 no.3
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• pp.137-141
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• 2002

Taurine, amino acid, chemically known as 2-amino ethane sulphonic acid was discovered more than two hundred years ago from ox bile. it is widely distributed in both mammals and nonmammals. It is found in considerably high amount in hUl11an: a normal adult of 70 kgs contains about 70 grams of taurine. Taurine with this much concentration, is involved in almost all life processes. Its deficiency causes several abnormalities in major organs like brain, eye and heart. Taurine-bone interaction is latest addition to its long list of actions. In bone cells, taurine is also found in high concentration. Taurine is found to help in enhancing the bone tissue formation which is evidenced by increased matrix formation and collagen synthesis. Besides stimulating the bone tissue formation, it also inhibits the bone loss through inhibiting the bone resorption and osteoclast formation. Thus, taurine acts as a double agent. In addition to these two major actions of taurine in bone, it also has beneficial effect in wound healing mld bone repair. Taurine possess radioprotective properties, too. As it is a naturally available molecule, it can be used as a preventive agent. Taurine has a potential to replace bisphosphonates which are currently in use for the inhibition of bone loss but this needs in depth study. As taurine is involved in bone formation and inhibition of bone loss, a detailed study can make it a single marker of bone metabolism. All these taurine-bone interaction is a symbol of their deep involvement but still require further extension to make taurine as a choice for tile sound bone health.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.463-469
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• 2016

In this paper, compressive strength and water permeability performance for two types of crack self-healing materials such as SH-PO-0 composed of mineral admixtures(expansive agent, swelling material and crystal growth agent) and SH-PO-(5, 15, 30) blended with SH-PO-0 and phosphate additive(PO) dissolving easily calcium ion, were evaluated. The test results show that the water flow of SH-PO-0 decreased steeply at the early age although compressive strength decreased about 9% at 28 days compared with OPC. The higher PO replacement ratio is, the lower compressive strength and more improved water permeability performance is, and thus, based on such results, adequate PO replacement ratio is 15%. It is also found that the self-healing performance of SH-PO-15 was quite improved at the early ages and however, the performance of SH-PO-15 is similar to one of SH-PO-0 at long-term ages, and 28 days compressive strength of SH-PO-15 decreased about 8% compared with SH-PO-0. In addition, it is confirmed from the analysis of SEM-EDS that calcium ions of SH-PO-15 were crystallized more than those of SH-PO-0.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.5
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• pp.887-893
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• 2011

The purpose of this study was to investigate the wound healing effects of Danggwieumja (DG), which is commonly used for skin inflammation, skin wound, skin pruritus, and chronic hives etc. The 1.5 cm ${\times}$ 1.5 cm full-thickness skin wound was induced to two groups, DG (n=16) and Saline (n=16) group. The DG extract and Saline were orally administrated daily for 15 days after skin wound induction. Then, the body weight of rats and the congestion indices were daily measured for 15 days after skin wound induction. The wound contractions and epithelizations were also measured. The wound contractions were daily measured for 15 days after wound induction and wound epithelizations were measured for 8 days from day 7 after wound induction. For evaluating angiogenesis, the immunoreactivities of vWF and VEGF protein were measured immunohistochemistrically on day 15. In results, although the percentage increases in mean body weight of rats in the DG and Saline groups hve no significant differences, DG extract decreased the time of wound healing and congestion around wound, and improved wound contraction and epithelization. The contraction percentage of DG group was significantly increased on day 5 (P<0.05) and day 7 (P<0.01) than that of Saline group. DG group showed significant increase of wound epithelization on day 7 (P<0.05) as compared to Saline group. Moreover, DG extract reduced the inflammation of skin dermis and promoted the growth of vascular vessels of dermis by accelerating vascular endothelial growth factor (VEGF) protein. These results suggest that DG has the beneficial effects on skin incision wound and can be the suitable wound healing agent for various surgical wounds.

• Archives of Plastic Surgery
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• v.35 no.2
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• pp.121-126
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• 2008

Purpose: Poly-N-acetyl glucosamine(PGlcNAc) nanofiber-based materials, produced by a marine microalga, have been characterized as effective hemostatic and angiogenic agents. The similarity between PGlcNAc patch and the natural extracellular matrix allows it to support new healthy tissue growth in an injured area and to encourage fluid absorption. In this study, we hypothesized that a poly-N-acetyl glucosamine fiber patch(PGlcNAc patch) may enhance wound healing in the db/db mouse. Methods: PGlcNAc patches were applied on one square centimeter, full-thickness, skin wounds in the db/db mouse model. Wounds(n=15 per group) were dressed with a PGlcNAc nanofiber patch for 1 hour(1 h), 24 hours(24 h) or left untreated(NT). After the application time, patches were removed and wounds were allowed to heal spontaneously. The rate of wound closure was evaluated by digital analysis of unclosed wound area in course of time. At day 10, wounds(n=7 per group) were harvested and quantified with immunohistochemical markers of proliferation(Ki-67) and vascularization (platelet endothelial cell adhesion molecule, PECAM-1). Results: Wounds dressed with PGlcNAc patches for 1 hour closed faster than control wounds, reaching 90% closure in 16.6 days, nine days faster than untreated wounds. Granulation tissue showed higher levels of proliferation and vascularization following 1 h treatment than the 24 h and NT groups. In addition to its hemostatic properties, the PGlcNAc material also appears to accelerate wound closure in healing-impaired genetically diabetic mice. Conclusion: This material, with its combination of hemostatic and wound healing properties, has the potential to be effective agent for the treatment of complicated wounds.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1668-1673
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• 2008

고분자 복합재 구조물의 경우 일반적으로 여러 층의 단층(laminar)이 적층된 구조로 이루어져 있으며, 모재균열, 층간분리 및 섬유파단과 같은 손상이 발생되어 파단에 이르게 된다. 자가손상 복구기법은 복합소재의 열경화성 수지 내에 손상복구액을 포함하고 있는 마이크로캡슐과 촉매를 투입하여 외부의 도움 없이 손상을 치료할 수 있는 방법으로, 소재의 디자인에 있어서 새로운 페러다임을 제공할 수 있는 것으로 현재 많은 연구가 진행되고 있다. 본 연구에서는 ENB(5-ethylidene-2-norbornene)와 DCPD(dicyclopentadiene)에 대하여 DMA(dynamic mechanical analysis)와 DSC(differential scanning calorimetry)를 이용하여 특성을 분석하였다. 또한 그들의 ROMP(ring-opening metathesis polymerization)반응과의 관계를 조사하였으며, ENB와 DCPD 블렌드에 대한 복구액으로서의 특성도 조사하였다. 본 연구실에서 합성된 두 가지 다른 종류의 ROMP 경화제에 대한 실제 자가손상복구에으로서의 적용상 특성도 연구하였다.

• Composites Research
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• v.17 no.4
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• pp.40-46
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• 2004

A single lap shear test was used to investigate the effects of the ratio of a catalyst to a self-healing agent and curing temperature on the bond performance of autonomic polymer composites. DCPD (dicyclopentadiene), ENB (5-ethylidene-2-norbornene), and their mixture were used as self-healing agents and bis(triclohexylphosphine) benzyllidine ruthenium (IV) dichloride Grubbs' catalyst was used as a catalyst. During the experiments, the catalyst ratios of 1.0wt% and 0.5wt% were applied to DCPD, the catalyst ratio of 0.lwt% was applied to ENB, and the catalyst ratio of 0.5wt% was applied to the mixtutes of DPCD and ENB. In addition, the curing temperatures of $25^{\circ}C$, $60{\circ}C$, and $80^{\circ}C$ were considered. According to the results, the higher catalyst ratio and the longer curing time were required to obtain more stabilized bond shear strength of DCPD. ENB with a lower catalyst ratio was cured faster than DCPD. Unlike DCPD, ENB stabilized after a steady fall from its peak as the curing time increased. Moreover, the mixtures of DCPD and ENB revealed similar curing behavior to ENB, but the increase in mixture ratio of ENB to DCPD caused curing process to be faster. Also the increase in curing temperature caused the bond shear strength to be higher and the curing time to be quicker.

• Archives of Plastic Surgery
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• v.41 no.5
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• pp.466-471
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• 2014

Background Bleeding can be a problem in wound debridement. In search for an effective hemostatic agent, we experimented with a chitosan film combined with the recombinant human epidermal growth factor (rh-EGF), hypothesizing that it would achieve effective hemostasis and simultaneously enhance arterial healing. Methods Forty-eight Sprague-Dawley rats were used, and 96 puncture wounds were made. The wounds were divided into the following four groups: treated with sterile gauze, treated with gelatin sponge, treated with chitosan, and treated with chitosan combined with rh-EGF. Immediate hemostasis was evaluated, and arterial healing was observed histologically. Results Groups B, C, and D showed a significant rate of immediate hemostasis as compared to group A (P<0.05), but there were no significant differences among groups B, C, and D. Histologically, only group D showed good continuity of the vessel wall after 1 week. It was the only group to show smooth muscle cell nuclei of the vessel wall. Conclusions We observed that chitosan has an effective hemostatic potential and the mix of rh-EGF and chitosan does not interfere with chitosan's hemostatic capabilities. We also identified enhanced healing of vessel walls when rh-EGF was added to chitosan. Further research based on these positive findings is needed to evaluate the potential use of this combination on difficult wounds like chronic diabetic ulcerations.

• Journal of Veterinary Clinics
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• v.23 no.1
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• pp.55-60
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• 2006

Aucuba japonica has variable pharmacological effects such as hepatoprotective, choleretic, hemodynamic, antimicrobial, and anti-inflammatory activities. This study was performed to investigate the effects of Aucuba japonica extract on oral wound healing. Aucubin was extracted from Aucuba japonica, and injected on either side of buccal mucosa of male mice. Artificial full thickness wounds were made on the site with 1.5 mm biopsy punch under sterile technique. The specimens had taken on day 1, 3, and 5 with 4 mm biopsy punch. Light microscopic examination and quantitative histologic analysis were performed for reepithelization, inflammatory cell infiltration. Reepithelization of the aucubin (0.1%) group was earlier than the control group. And the number of inflammatory cells of the aucubin group was lesser than the control group. In view of the results so far achieved, the aucubin extracted from Aucuba japonica may be useful for oral wound healing and it can be applied as a topical agent on the oral wound. Further research should be performed on the mechanism of aucubin on oral wound healing and proper formulation for effective topical agents.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.9
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• pp.199-206
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• 2019

Experimental study on the durability characteristics to examine the feasibility of concrete with high water-tightness and self-healing performance to minimize maintenance of concrete for artificial ground is as follows. 1) When blending agent, swelling agents, and curing accelerator were added on the ternary system cement with blast-furnace slag fine particles and fly ash to give a self-healing property, higher blending strengths by 82% at design standard strength of 24MPa and by 74% at design strength of 30MPa, respectively could be obtained. 2) The permeability test for the specimens having high water-tightness and no shrinkage showed that the permeability was reduced at maximum of 98%. However, the permeability was decreased as the design strength was increased, showing the reduction rate of 87% at the design strength of 50MPa. 3) The depth of carbonation of blast-furnace slag and fly ash was increased in all the specimens compared with those of OPC only. However, as the material age was increased, carbonation penetration depth was decreased compared with the reference blend. 4) Compared with the reference blending using only OPC, the freeze-thaw resistance was higher in the case of blending with 40% of blast-furnace slag and 10% of fly ash at the design standard strength of 50MPa. In addition, the freeze-thaw resistance in general was superior in the design standard strength of 50MPa with the lower water-binder ratio (W/B) as compared with the design standard strength of 24MPa and 30MPa with the high water-binder ratios.

• Polymer(Korea)
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• v.39 no.1
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• pp.56-63
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• 2015

The object of this study is to prepare microcapsules containing a diisocyanate compound, apply them to self-healing protective coating, and evaluate the self-healing capability of the coating by atmospheric moisture. Isophorone diisocyanate (IPDI) polymerized under humid atmosphere, indicating that IPDI can be used as a healing agent. Microencapsulations of IPDI were conducted via interfacial polymerization of a polyurethane prepolymer with diol compounds. The formation of microcapsules was confirmed by Fourier-transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The mean diameter, size distribution, morphology and shell wall thickness of microcapsules were investigated by optical microscopy and scanning electron microscopy (SEM). The properties of microcapsules were studied by varying agitation rates and diol structure. The self-healing coatings were prepared on test pieces of CRC board. When scratch was generated in the coatings, the core material flew out of the microcapsules and filled the scratch. The self-healing coatings were damaged and healed under atmosphere with 68~89% relative humidity for 48 h, and SEM and impermeability test for the specimens showed that the scratch could be healed by atmospheric moisture.