• 폴리머
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• 제32권6호
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• pp.544-548
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• 2008

본 연구에서는 키틴의 알칼리 가수분해를 통해 탈아세틸화도가 조절된 세 가지 조건의 키토산을 제조하였고, 이 키토산이 수용성을 지니게 화학적 분해법을 이용해 분자량을 조절하였다. 이렇게 제조된 분자량이 조절된 세 가지 조건의 탈아세틸화도를 가지는 키토산 각각에 항산화제인 리포산을 합성하여 항산화 능력을 가지는 생체 적합성 나노 구조체를 형성하였다. 키토산-리포산의 합성을 확인하기 위하여 분광학적 분석 방법을 사용하여 분석하였다. 키토산-리포산 합성체는 수용액 상태에서 자기조립체를 형성하며 이렇게 형성된 자기조립체 나노 입자는 약 135 nm 정도의 크기를 가지고 있음을 알 수 있었다.

• 한국응용과학기술학회지
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• 제37권2호
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• pp.173-182
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• 2020

본 연구에서는 주류공장 내 고농도 CO₂ 제거 및 포집을 위해 L-alanine 흡수제를 적용하여 CO₂ 흡수, 탈리 효율을 평가 후 재생 성능을 확인하였다. 탈리공정의 효율적인 처리를 평가하기 위해 실험실 규모에서 Hot plate, Steam 두가지 탈리 방법을 비교하였으며 Hot plate는 약 10%, Steam의 경우 약 60%의 재생효율을 확인하였다. 따라서 주류공장 내 100㎥/min 실증화 규모에 Steam-Tower 탈리공정을 적용하여 최적조건을 평가한 결과 탈리 유량 4L/min 이하, Steam 온도 160℃ 이상, 탈리효율 85.5%로 확인할 수 있었다.

• Journal of Periodontal and Implant Science
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• 제25권2호
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• pp.407-417
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• 1995

In order to evaluate the effect of platelet-derived growth factor(PDGF-BB) and guided tissue regeneration(GTR) technique on the regeneration of destructed periodontal tissue,intentional through-and-through furcation defects(4mm in height) were made on both mandibular 2nd and 4th premolars of 8 adult male dogs(30-40lb). Experimental group 1 was composed of the premolars that were treated by only topical application of PDGF-BB with 0.05M acetic acid without any barrier membrane. Experimental group 2 was composed of the premolars that were treated by GTR with expanded polytetrafluoroethylene membrane(ePTFE : Gore-tex periodontal material, USA). Experimental group 3 was composed of the premolars that were treated by GTR with ePTFE after topical application of PDGFBE. Control group was composed of the premolars that were treated by coronally positioned flap operation only without use of PDGF-BB and ePTFE membrane. All ePTFE membranes were carefully removed 4 weeks after regenerative surgery, and all experimental animals were sacrificed 8 weeks after regenerative surgery. The light microscopic findings were as follows ; (1) In experimental group 1, rapid new bone formation along the-root surface with multiple ankylosis and root resorption by multinucleated giant cells, and dense connective tissue in the central portion of the furcation defects were observed. (2) In experimental group 2, it was observed that the furcation defects were filled with newly formed bone, Sharpey's fibers were embedded into new cementum on root dentin of furcation fornix area, but the central portion and the area under furcation fornix were still filled with dense connective tissue. (3) In experimental group 3, the furcation defects were regenerated with newly formed dense bone and regular periodontal ligament with Sharpey's fibers embedded into newly formed cementum and bone underneath fornix area. (4) In control group, unoccupied space, apical migration of epithelium, dense infiltration of inflammatory cells in subepithelial connective tissue in relation to heavy plaque accumulation, and root resorption by inflammatory reaction were shown, but any new cementum formation on resorbed dentin surface could not be observed. The present study demonstrated that the combined therapy of PDGF-BB and GTR could enhance the regeneration of destructed periodontal tissue.

• Journal of Plant Biotechnology
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• 제36권2호
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• pp.174-178
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• 2009

Presently, we report a simple, reproducible and high frequency plant regeneration in Hibiscus syriacus L. using axillary buds. H. syriacus was regenerated from axillary buds directly or through a callus phase. Regenerated shoots were directly induced from young and fresh axillary buds cultured on Murashige and Skoog medium (MS) supplemented with 0.01 mg/L of the growth regulator thidiazuron (TDZ) after 2 weeks of culture. Directly induced shoots were transferred to hormone-free MS medium and root development was observed after 6 weeks. On the other hand, old and stale axillary buds were regenerated to shoots via callus induction on MS medium containing 0.01–2 mg/L TDZ after 4 weeks. A TDZ concentration of 0.01 mg/L was most effective in callus formation. Green callus was transferred to MS medium containing 0.01 mg/L α-naphthalene acetic acid (NAA) and 0.5 mg/L benzylaminopurine (BA). After 4 weeks, callus had developed into multiple shoots. Plantlets were formed from 10 week cultures of single shoots on hormone-free MS medium. Regenerated plantlets were cultured on MS medium for one month and then transferred to pots containing garden soil. Potted plants were acclimatized for one month and grown to maturity under greenhouse conditions. The present study has shown that various concentrations of plant growth regulator can be effective for in vitro plant regeneration of H. syriacus. The direct and indirect regeneration protocol presented here will be useful for understanding the manipulation and propagation of H. syriacus.

• 식물조직배양학회지
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• 제25권6호
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• pp.501-505
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• 1998

오이의 국내 F1 품종인 조생낙합의 하배축 유래 배발생 현탁배양 세포의 초저온 보존 시스템을 개발하였다. 액체질소 저장 후 캘러스 재생률은 2M DMNSO와 0.4 M sucrose를 혼용 처리하였을 때 캘러스 재생률이 85%로 가장 높았다. 그러나 glycerol 처리구에서는 처리농도에 상관없이 모든 처리구에서 캘러스 재생이 이루어지지 않았다. 또한 고농도의 삼투용액에서 배양세포의 전처리 과정은 필요하지 않았다. 재생된 캘러스를 1 mg/L 2,4-D가 첨가된 MS 배지로 이식하여 배양하였을 때 다수의 체세포배가 발달하였으며, 체세포배를 MS 기본배지로 옮겨 명배양한 결과 다수의 소식물체가 발달하였다.

• Archives of Pharmacal Research
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• 제28권11호
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• pp.1311-1316
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• 2005

To better define the relationship between dermal regeneration and wound contraction and scar formation, the effects of epidermal growth factor (EGF) loaded in collagen sponge matrix on the fibroblast cell proliferation rate and the dermal mechanical strength were investigated. Collagen sponges with acid-soluble fraction of pig skin were prepared and incorporated with EGF at 0, 4, and 8 $\mu$g/1.7 $cm^{2}$. Dermal fibroblasts were cultured to 80$\%$ confluence using DMEM, treated with the samples submerged, and the cell viability was estimated using MTT assay. A deep, $2^{nd}$ degree- burn of diameter 1 cm was prepared on the rabbit ear and the tested dressings were applied twice during the 15-day, post burn period. The processes of re-epithelialization and dermal regeneration were investigated until the complete wound closure day and histological analysis was performed with H-E staining. EGF increased the fibroblast cell proliferation rate. The histology showed well developed, weave-like collagen bundles and fibroblasts in EGF-treated wounds while open wounds showed irregular collagen bundles and impaired fibroblast growth. The breaking strength (944.1 $\pm$ 35.6 vs. 411.5 $\pm$ 57.0 Fmax, $gmm^{-2}$) and skin resilience (11.3 $\pm$ 1.4 vs. 6.5 $\pm$ 0.6 mJ/$mm^{2}$) were significantly increased with EGF­treated wounds as compared with open wounds, suggesting that EGF enhanced the dermal matrix formation and improved the wound mechanical strength. In conclusion, EGF-improved dermal matrix formation is related with a lower wound contraction rate. The impaired dermal regeneration observed in the open wounds could contribute to the formation of wound contraction and scar tissue development. An extraneous supply of EGF in the collagen dressing on deep, $2^{nd}$ degree-burns enhanced the dermal matrix formation.

• Journal of Microbiology and Biotechnology
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• 제22권10호
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• pp.1406-1411
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• 2012

5,5'-Dithiobis(2-nitrobenzoic acid) (DTNB) was selected as an electron transfer mediator and was covalently immobilized onto high porosity carbon cloth to employ as a working electrode in an electrochemical $NAD^+$-regeneration process, which was coupled to an enzymatic reaction. The voltammetric behavior of DTNB attached to carbon cloth resembled that of DTNB in buffered aqueous solution, and the electrocatalytic anodic current grew continuously upon addition of NADH at different concentrations, indicating that DTNB is immobilized to carbon cloth effectively and the immobilized DTNB is active as a soluble one. The bioelectrocatalytic $NAD^+$ regeneration was coupled to the conversion of L-glutamate into ${\alpha}$-ketoglutarate by L-glutamate dehydrogenase within the same microreactor. The conversion at 3 mM monosodium glutamate was very rapid, up to 12 h, to result in 90%, and then slow up to 24 h, showing 94%, followed by slight decrease. Low conversion was shown when substrate concentration exceeding 4 mM was tested, suggesting that L-glutamate dehydrogenase is inhibited by ${\alpha}$-ketoglutarate. However, our electrochemical $NAD^+$ regeneration procedure looks advantageous over the enzymatic procedure using NADH oxidase, from the viewpoint of reaction time to completion.

• 생약학회지
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• 제53권2호
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• pp.70-78
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• 2022

The objective of this study was to assess the effect of preventing pigmentation caused by external stimuli, promoting skin regeneration and whitening of the skin composition containing complex extract of Dendrobii Caulis and Centella asiatica (CE). We evaluated cell viability, tyrosinase and melanin inhibition activity, skin irritation test, and skin moisturizing and regenerative effects using CE. As a result of the tyrosinase inhibitory activity, 100 ㎍/mL CE (35.31%) showed higher value than kojic acid (21.32%). The results of melanin synthesis inhibition in B16F10 melanoma cells after treatment with α-melanocyte stimulating hormone showed a similar level of activity to that of arbutin, indicating an excellent whitening effect. In clinical test of the skin composition containing CE, we confirmed that CE is non-irritated in human skin primary irritation test as well as have a high skin moisturizing and regenerative effect. From these results, we suggested the CE not only prevents skin damage and pigmentation caused by external stimuli but has remarkable skin brightening activity and skin regeneration effect.

• Food Science and Biotechnology
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• 제16권4호
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• pp.605-609
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• 2007

The effects of lactic acid fermented yam yogurt (Yam/YG) on colon mucosal tissue were investigated in a loperamide-induced constipation rat models. Sprague-Dawley rats were fed for 6 weeks with 3 types of diets (normal, supplemented with lactic acid bacteria, and supplemented with Yam/YG), and were then administered loperamide intraperitoneally twice daily for 5 days. Administration of loperamide decreased fecal excretion and the moisture content of feces with increasing of numbers of pellets in the colon. On the histopathologic findings from hematoxylin and eosin (H& E) and alcian blue stainings, supplementation with Yam/YG resulted in the recovery of depleted goblet cells and mucin, and increased the numbers of Ki-67 positive cells, indicating restoration of colonic mucosa through cell proliferation and crypt regeneration against damages observed in crypt epithelial cells of loperamide-induced rats. These results indicate that Yam/YG improves evacuation and mucus production in the gastrointestinal tracts of constipated-induced rats.

• 자원리싸이클링
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• 제5권2호
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• pp.57-62
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• 1996

철강산세작업중 발생하는 폐산세용액의 재활용중 산화철이 부산물로 생산되고 있다. 이 산화철은 안료 및 훼라이트원료로 사용되고 있다. 훼라이트원료로 사용되는 산화철은 불순물을 엄격히 제한하고 있다. 본 연구에서는 산화철의 주요 불순물인 실리카 및 기타성분을 제거하기 위하여 폐산세용액에서 여과법, 흡착매체법, Fe leaching, 중화법 등 여러 가지 제거방법으로 불순물제거 실험을 하여, 각 방법의 효과를 고찰하였다.