• 공업화학
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• 제31권3호
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• pp.341-345
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• 2020

하폐수처리 및 정수처리에 사용되는 활성탄 흡착 공정에서 기존의 활성탄 열재생법 비해 활성탄 손실과 불완전 연소로 인한 오염물질 발생도 적으며, 사용 활성탄의 인발-재생-재충진에 소요되는 시간의 절약이 가능한 재생 방법으로 오존수를 이용한 in situ regeneration에 대한 기초연구를 수행하였다. 활성탄 흡착 컬럼 상에서 페놀(phenol) 및 PEG를 흡착 파과 시킨 후 오존수 접촉으로 흡착물질을 분해 제거하는 흡착-재생 싸이클을 반복하였다. 오존수 접촉에 의한 재생 횟수가 증가할수록 페놀 흡착용량은 어느 정도 감소하지만, 일정 수준으로의 감소 후에는 구조 변화가 안정화되어 추가적인 감소가 일어나지 않았다. 흡착 용량이 감소하는 이유는 오존과의 반응에 의해 활성탄의 미세공 크기가 증가하면서 비표면적이 감소하기 때문으로 나타났다. 이러한 세공 크기의 변화와 비표면적의 변화로 인하여 재생 후 in-pore adsorption이 우세한 페놀과 같은 저분자량 물질의 흡착효율은 감소하게 되나 external adsorption 비율이 큰 PEG와 같은 고분자량 물질의 흡착효율은 크게 영향을 받지 않았다. 세공 크기 및 비표면적의 변화는 오존수와의 접촉시간이 길어질수록 심화되므로 제거하려는 물질의 크기를 고려하고 접촉시간을 조절함으로써 흡착 효율의 유지를 제어하는 것이 필요하다.

• Environmental Engineering Research
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• 제13권4호
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• pp.177-183
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• 2008

Ex-situ reductive dechlorination of carbon tetrachloride (CT) by iron sulfide in a batch reactor was characterized in this study. Reactor scaled-up by 3.5 L was used to investigate the effect of reductant concentration on removal efficiency and process optimization for ex-situ degradation. The experiment was conducted by using both liquid-phase and gas-phase volume at pH 8.5 in anaerobic condition. For 1 mM of initial CT concentration, the removal of the target compound was 98.9% at 6.0 g/L iron sulfide. Process optimization for ex-situ treatment was performed by checking the effect of transition metal and mixing time on synthesizing iron sulfide solution, and by determining of the regeneration time. The effect of Co(II) as transition metal was shown that the reaction rate was slightly improved but the improvement was not that outstanding. The result of determination on the regeneration time indicated that regenerating reductant capacity after $1^{st}$ treatment of target compound was needed. Due to the high removal rates of CT, ex-situ reductive dechlorination in batch reactor can be used for basic treatment for the chlorinated compounds.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2006년도 제46회 종합학술대회 연제초록
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• pp.27-28
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• 2006

• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.215-220
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• 2013

Recently, the RNA/DNA-binding protein FUS, Fused in sarcoma, was shown to play a role in growth, differentiation, and morphogenesis in vertebrates. Because little is known about Fus, we investigated its expression pattern in murine tooth development. In situ hybridization of mouse mandibles at specific developmental stages was performed with a DIG-labeled RNA probe. During early tooth development, Fus was detected in the dental epithelium and dental mesenchyme at 11 days postcoitum (dpc) and 12 dpc. From 14 dpc, Fus was strongly expressed in the dental papilla and the cervical loop of the dental epithelium. At postnatal day 4 (PN4), Fus expression was observed in the odontoblasts, ameloblasts, the proliferation zone of the pulp, and the cervical loop. At PN14, the expression pattern of Fus was found to be maintained in the odontoblasts and the proliferation zone of the pulp. Furthermore, Fus expression was especially strong in the Hertwig's epithelial root sheath (HERS). Therefore, this study suggests that Fus may play a role in the HERS during root development.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.183-183
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• 2006

Hyaluronic acid and chitosan-based poly(ethylene oxide) (HA-PEO and Chitosan-PEO) hydrogels have been employed as unique biomedical polymeric materials with properties such as bioactivity from polysaccharide, biocompatibility of HA and chitosan as well as PEO and control release of bioactive molecules from the hydrogel itself. We here examine in situ hydrogels based on hyaluronic acid and chitosan in terms of their synthesis, mechanical properties, morphologies and in vitro cellular interactions on their surface and inside. In vivo bone regeneration of HA-PEO and Chitosan-PEO hydrogels was compared with in mouse model.

• Journal of Periodontal and Implant Science
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• 제42권1호
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• pp.13-19
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• 2012

Purpose: The aim of this study was to examine whether a previous peri-implantitis site can affect osseointegration, by comparing implant placement at a site where peri-implantitis was present and at a normal bone site. A second aim of this study was to identify the tissue and bone reaction after treating the contaminated implant surface to determine the optimal treatment for peri-implant diseases. Methods: A peri-implant mucositis model for dogs was prepared to determine the optimal treatment option for peri-implant mucositis or peri-implantitis. The implants were inserted partially to a length of 6 mm. The upper 4 mm part of the dental implants was exposed to the oral environment. Simple exposure for 2 weeks contaminated the implant surface. After 2 weeks, the implants were divided into three groups: untreated, swabbed with saline, and swabbed with $H_2O_2$. Three implants from each group were placed to the full length in the same spot. The other three implants were placed fully into newly prepared bone. After eight weeks of healing, the animals were sacrificed. Ground sections, representing the mid-buccal-lingual plane, were prepared for histological analysis. The analysis was evaluated clinically and histometrically. Results: The untreated implants and $H_2O_2$-swabbed implants showed gingival inflammation. Only the saline-swabbed implant group showed re-osseointegration and no gingival inflammation. There was no difference in regeneration height or bone-to-implant contact between in situ implant placement and implant placement in the new bone site. Conclusions: It can be concluded that cleaning with saline may be effective in implant decontamination. After implant surface decontamination, implant installation in a previous peri-implant diseased site may not interfere with osseointegration.

• Animal cells and systems
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• 제14권2호
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• pp.73-81
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• 2010

In this study, monoclonal antibodies against lysosomal acid phosphatase (LAP) of a salamander, Hynobius leechii, were used to determine the spatial and temporal expression of the LAP in the regenerating limbs. The Western blot and immunohistochemical analysis in the limb regeneration revealed that LAP was highly expressed at the dedifferentiation stage, especially in the wound epidermis and dedifferentiating limb tissues such as muscle and cartilage. With RA treatment, the LAP expression became upregulated in terms of both level and duration in the wound epidermis, blastemal cell and dedifferentiating limb tissues. In addition, in situ activity staining of LAP showed a similar result to that of immunohistochemistry. Thus, the activity profile of LAP activity coincides well with the expression profile of LAP during the dedifferentiation period. Furthermore, to examine the effects of lysosomal enzymes including LAP on salamander limb regeneration, lysosome extract was microinjected into limb regenerates. Interestingly, when the lysosome extract was microinjected into limb regenerates with a low dose of RA($50\;{\mu}g/g$ body wt.), skeletal pattern duplication occurred frequently in the proximodistal and transverse axes. Therefore, lysosomal enzymes might cause the regenerative environment and RA plays dual roles in the modification of positional value as well as evocation of extensive dedifferentiation for pattern duplication. In conclusion, these results support the hypothesis that dedifferentiation is a crucial event in the process of limb regeneration and RA-evoked pattern duplication, and lysosomal enzymes may play important role(s) in this process.

• 대한환경공학회지
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• 제34권10호
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• pp.664-670
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• 2012

상용 중유 발전소 배가스에 장기간 노출되어 활성이 현저히 저하된 탈질 SCR 폐촉매를 대상으로 현장 시스템을 모사하여 증류수 및 산성용액에 의한 세척과정을 거쳐 모사된 현장 조건으로 촉매를 재생하였다. 산성용액의 제조조건 및 처리조건에 따른 촉매의 물성변화를 확인하였고 질소산화물($NO_x$) 전환 촉매 활성 실험을 수행하여 촉매성능 변화를 고찰하였다. 촉매의 특성분석은 BET, Porosimeter, EDX (Energy Dispersive X-ray spectrometer), ICP (Inductively Coupled Plasma) 등을 이용하여 수행하였고, $NO_x$ 전환 반응실험은 중유 발전소 배가스를 모사하여 마이크로 반응기에서 SCR 반응을 수행하였다. 촉매특성 분석결과 재생된 촉매의 경우 비표면적은 신품 촉매 대비 95% 이상 회복되었고, $NO_x$ 전환활성은 산성용액 농도 3~6 M 범위에서 신품 촉매 대비 90% 이상을 회복한 것으로 나타났다. 이러한 촉매활성의 향상은 산성용액에 의한 촉매표면의 불순물들이 제거되면서 일어난 결과로 밝혀졌다.

• Journal of Plant Biotechnology
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• 제6권2호
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• pp.77-85
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• 2004

Development of efficient plant regeneration and genetic transformation protocols (using the Particle Inflow micro-projectile Gun and the shoot-tips as target tissue) of Sorghum bicolor (L.) Moench in terms of expression of the reporter gene, $\beta$-glucuronidase(uidA) is reported here. Two Indian cultivars of sorghum were used in the study, viz. M-35-1 and CSV-15. Plant regeneration was achieved from one-week-old seedling shoot-tip explants via multiple-shoot-clumps and also somatic embryos. The multiple-shoot-clumps were produced on MS medium containing BA (0.5, 1.0 or 2.0 mg/$L^{-1}$), with biweekly subculture. Somatic embryos were directly produced on the enlarged dome shaped expansive structures that developed from shoot-tip explants (without any callus formation) when cultured on MS medium supplemented both with BA (0.5, 1.0 or 2.0 mg/$L^{-1}$) and 2,4-D (0.5 mg/$L^{-1}$). Whereas each multiple-shoot-clump was capable of regenerating more than 80 shoots via an intensive differentiation of both axillary and adventitious shoot buds, the somatic embryos were capable of 90% germination, plant conversion and regeneration. The regenerated shoots could be efficiently rooted on MS medium containing 1.0mg/$L^{-1}$ IBA and successfully transplanted to the glasshouse and grown to maturity with a survival rate of 92%. The plant regeneration efficiency of both the genotypes were similar. After the micro-projectile bombardment, expression of uidA gene was determined by scoring blue transformed cell sectors in the bombarded tissue by an in situ enzyme assay. The optimal conditions comprising a helium pressure of 2200 K Pa, the target distance of 11 cm with helium inlet fully opened and the use of osmoticum have been defined to aid our future strategies of genetic engineering in sorghum with genes for tolerance to biotic and abiotic stresses.

• Plant Resources
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• 제7권1호
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• pp.39-46
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• 2004

To demonstrate the importance of transformation efficiency in independent event, molecular and cytogenetic analysis were conducted with genomic DNA and chromosome of transgenic plants produced by Agrobacterium tumefeciens LBA4404 (pSBM-PPGN: gusA and bar). Selection ratios of putative transgenic calli were similar in independent experiments, however, transformation efficiencies were critically influenced by the type of regeneration media. MSRK5SS-Pr regeneration mediun, which contains 5 mgL$^{-1}$ kinetin, 2% (w/v) sucrose in combination with 3% (w/v) sorbitol, and 500 mgL$^{-1}$ proline, was efficient to produce transgenic plant of rice from putative transgenic callus in the presence of L-phosphinotricin (PPT). With MSRK5SS-Pr medium, transformation efficincies of Nagdongbyeo were significantly enhanced from 3.7% to 6.3% in independent callus lines arid from 7.3% to 19.7% in plants produced, respectively. Stable integration and expression of bar gene were confirmed by basta herbicide assay, PCR amplification and Southern blotting of bar gene, and fluorescence in situ hybridization (FISH) analysis using pSBM-PPGN as a probe. In Southern blot analysis, diverse band patterns were observed in total 44 transgenic plants regenerated from 20 independent PPT resistant calli showing from one to five copies of T-DNA segments, however, the transformants obtained from one callus line showed the same copy numbers with the same fractionized band patterns.