• 제목/요약/키워드: Gradual Regeneration

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Regeneration of Spent Carbon by a Novel Oxidative Thermal Process

  • 류건상;Shybender Kapila
    • Bulletin of the Korean Chemical Society
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    • 제18권8호
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    • pp.811-814
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    • 1997
  • An oxidative thermal regeneration process was developed and evaluated for its potential applicability in several environmental areas. The feasibility of the process is affected strongly by the gradual carbon loss, energy consumption, physical changes of carbon, and effective destruction efficiency of adsorbed materials during the regeneration. The aim of the study is to determine the optimum conditions to maintain acceptable destruction efficiency for adsorbed organics, controlling oxidant flow rate. Prior to its applications, various preliminary tests were carried out to determine the effects of experimental parameters on the process. The tests performed were reaction temperature, carbon loss, surface area, surface structure, and adsorptive property. The results of these tests show that the parameters are dependent on oxidant flow rate, and suggest that the process is comparable and, in some ways, possibly superior to conventional regeneration techniques because the oxidative process is a single step and less energy intensive.

Regeneration of Exhausted Activated Carbon by a Countercurrent Oxygen Reaction

  • 류건상;김태동;김유항
    • Bulletin of the Korean Chemical Society
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    • 제20권12호
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    • pp.1447-1450
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    • 1999
  • Countercurrent oxygen reaction (COR) was developed and evaluated for regeneration of exhausted activated carbon. Whether the regeneration technique is feasible or not is affected strongly by gradual loss and physical changes of activated carbon, energy consumption, and effective removal of adsorbed materials during the process. Various parameters such as reaction temperature, the loss of activated carbon, surface area, pore volume, surface structure, adsorptive property, etc. were examined to determine the effectiveness of COR. The results of these tests showed that the parameters were strongly dependent on oxidant flow rate, and suggest that the newly developed COR is comparable and, in some ways, possibly superior to conventional regeneration techniques because the overall process runs in a single step and is less energy intensive, and also because the adsorptive capacity of exhausted activated carbon was completely recovered.

자가치아를 이용한 골이식재의 임상적 유용성: 일차 보고 (Clinical Effectiveness of Bone Grafting Material Using Autogenous Tooth: Preliminary Report)

  • 이정훈;김수관;문성용;오지수;김영균
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제33권2호
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    • pp.144-148
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    • 2011
  • Purpose: The purpose of this study was to evaluate the effectiveness of a novel bone grafting material using an autogeneous tooth (AutoBT) and provide the basis for its clinical application. The AutoBT contains organic and inorganic mineral components and is prepared from autogenous grafting material, thus eliminating the risk of immune reactions that may lead to its rejection. AutoBT can be used as bone material as is has both osteoinduction and osteoconduction activities at guided bone regeneration for implant placement and maxillary sinus graft. Methods: In a total of 63 patients, guided bone regeneration surgery was performed at the time of implant placement, and tissue samples were harvested at the time of the second surgery with the patient's consent. Results: There were no complications in guided bone regeneration using autogeneous tooth. Conclusion: We concluded that AutoBT underwent gradual resorption and was replaced by new bone of excellent quality via osteoinduction and osteoconduction.

도시재생사업 효과 분석 - 청주시 중앙동을 중심으로 - (Analyzing Urban Regeneration Effects - Focused on Jungang-Dong, Cheongju City -)

  • 한동욱;김태영;주수민;김혜주;홍명기;백종인;반영운
    • 지역연구
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    • 제34권1호
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    • pp.61-75
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    • 2018
  • 도시재생에 관한 연구는 2006년 이래로 10년이 넘는 기간 동안 활발히 진행되어오고 있다. 지금까지 많은 도시 재생사업 효과를 분석하기 위한 연구가 진행되고 있으나 대부분 정성적인 방법에 치우쳐 있다. 따라서 본 연구는 다양한 상업지역 도시재생사업이 진행 중에 있는 청주시 중앙동을 중심으로 도시재생사업의 효과를 정량적으로 분석하는 데 그 목적이 있다. 이를 위하여 유동인구, 공시지가 공실률을 도시재생사업 효과 분석 지표로 선정하였다. 분석시점은 도시재생의 효과가 본격적으로 나타나기 시작한 2013년을 기점으로 2011년부터 2016년까지이다. 분석결과, 첫째, 유동인구는 차츰 증가하다가 프로젝트가 활발히 진행되던 2014년에 약 65퍼센트의 증가율을 보였다. 둘째, 공시지가는 도시재생이 시작한 2011-2012 시점에 가장 큰 증가 폭을 보였고 2015년까지 증가폭이 점차 줄어들면서 2015-2016년에는 미세한 감소를 보였다. 마지막으로 공실률은 꾸준한 하향곡선을 그리며 27퍼센트에서 12퍼센트로 약 15퍼센트포인트가 감소하였다. 본 연구는 상업지역의 도시재생 효과를 정량적으로 분석한데서 학술적인 의의를 찾을 수 있다.

Flurbiprofen 함유 키토산 제제가 치은 섬유아세포에 미치는 영향 (Biological Effects Of Flurbiprofen Loaded Chitosan To Gingival Fibroblast)

  • 정종평;박윤정;이승진;유인철;최상묵
    • Journal of Periodontal and Implant Science
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    • 제26권1호
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    • pp.317-333
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    • 1996
  • The main goal of periodontal regeneration is to be achieved by epithelial exclusion, periodontal ligament cell activation or alveolar bone regeneration. The purpose of this study was to investigate on the physico- chemical and biological characteristics of biodegradable chitosan beads. Chitosan beads were fabricated by ionic gelation with sodium tripolyphosphate and they had the size in 300um diameter. As therapeutic agent, flurbiprofen was incorporated into the beads by 10, 20% loading contents. The release of drugs from the chitosan beads was measured in vitro. Also, biological activity tests of flurbiprofen loaded chitosan beads including cytotoxicity test, ihhibition of $IL-1{\beta}$ production, suppression to $PGE_2$ production, collagenase inhibition test, the ability of total protein synthesis, and tissue response were evaluated. The amount of flurbiprofen released from chitosan was 33-50% during 7 days. Minimal cytotoxicity was observed in chitosan beads. Flurbiprofen released from chitosan beads significantly suppressed the $IL-1{\beta}$ production of monocyte, $PGE_2$ production and markedly inhibited collagenase activity. Meanwhile, flurbiprofen released from this system showed increased ability for protein synthesis. Throughout 4 -week implantation period, no significant inflammatory cell infiltrated around chitosan bead and also fibroblast like cell types at the beads - tissue interface were revealed with gradual degradation of implanted chitosan beads. From these results, it was suggested that flurbiprofen loaded chitosan beads can be effectively useful for biocompatible local delivery system in periodontal regeneration.

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Rescue of a periodontally compromised tooth by non-surgical treatment: a case report

  • Cho, Young-Dan;Kim, Sungtae;Koo, Ki-Tae;Seol, Yang-Jo;Lee, Yong-Moo;Rhyu, In-Chul;Ku, Young
    • Journal of Periodontal and Implant Science
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    • 제46권2호
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    • pp.128-134
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    • 2016
  • Purpose: This article describes a case of the successful non-surgical management of a periodontally compromised maxillary premolar. Methods: A combination therapy, including root planing, occlusal adjustment, and tooth splinting, was applied. Clinical and radiographic examinations were performed during the 16-month follow-up period. Results: All periodontal parameters were improved. There were dramatic decreases (3-6 mm) in the probing pocket depth, tooth mobility, and marginal bone loss. Interestingly, gradual resolution of the periapical radiolucency and alveolar bone regeneration were observed in the radiographs, and the periodontal condition was maintained during the follow-up period. Conclusions: Within the limits of this study, these results demonstrate the importance of natural tooth preservation through proper periodontal treatment and occlusal adjustment of the periodontally compromised tooth, which is typically targeted for tooth extraction and dental implantation.

귀에 존재하는 내인성 성체줄기세포 (Endogenous Stem Cells in the Ear)

  • 박경호
    • Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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    • 제56권12호
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    • pp.749-753
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    • 2013
  • Basically stem cells have characteristics of multi-potency, differentiation into multiple tissue types, and self-renew through proliferation. Recent advances in stem cell biology can make identifying the stem-cell like cells in various mammalian tissues. Stem cells in various tissues can restore damaged tissue. Stem cells from the adult nervous system proliferate to form clonal floating colonies called spheres in vitro, and recent studies have demonstrated sphere formation by cells in the tympanic membrane, vestibular system, spiral ganglion, and partly in the organ of Corti. The presence of stem cells in the ear raises the possibilities for the regeneration of the tympanic membrane & inner ear hair cells & neurons. But the gradual loss of stem cells postnatally in the organ of Corti may correlate with the loss of regenerative capacity and limited hearing restoration. Future strategies using endogenous stem cells in the ear can be the another treatment modality for the patients with intractable inner ear diseases.

Aspects of spike damage by cold stress during young spike development period in wheat

  • Ahn, Seunghyun;Kim, Deawook;Lee, Hyeonseok;Jeong, Jaehyeok;Jeong, Hanyong;Hwang, Woonha;Choi, Kyungjin;Park, Hongkyu;Youn, Jongtag
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.199-199
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    • 2017
  • This study investigated the aspects of damage due to low temperature treatment in order to establish the damage criterion according to low temperature invasion during regeneration period in wheat after regeneration period in the early spring. We cultivated wheat cultivar 'Geumgang' in Wagner pots and treated them with three types of low temperature, and the gradual temperature change program was set in a low temperature incubator for 12.5 h per day for 5 days during the night time when the length of young spikes was about 1 mm. All treatments except for the control were treated in 5 steps for each temperature. Treatment 1 was treated at the lowest temperature $-5^{\circ}C$ for 5 h, treatment 2 for 7 h at $-5^{\circ}C$, and treatment 3 for 9 h at $-5^{\circ}C$. The most common type of damage was partial infertility, and there were some discolored spikes. The damage rate of wheat spikes treated at $-5^{\circ}C$ for 9 h was the highest, while the damage rates of wheat sprouts treated at 5h and 7h were not different from each other. It was found that the damage of wheat spikes exposed to low temperatures for a long time was large. It is necessary to investigate the aspects of spike damage by duration days of low temperature.

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Sensory recovery after infraorbital nerve avulsion injury

  • Lee, Sam Yong;Kim, Seung Hyun;Hwang, Jae Ha;Kim, Kwang Seog
    • 대한두개안면성형외과학회지
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    • 제21권4호
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    • pp.244-248
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    • 2020
  • The infraorbital nerve is a branch of the trigeminal nerve. Injury to the infraorbital nerve can be caused by trauma, including various facial fractures. Due to this nerve injury, patients complain of numbness and pain in the entire cheek, the ala of nose, and upper lip. In general, spontaneous sensory recovery is expected after decompressive surgery. If nerve transection is confirmed, however, neurorrhaphy is typically performed. Here, we present a case in which microsurgery was not performed in a patient with Sunderland grade V avulsion injury of the infraorbital nerve due to a facial bone fracture. Gradual nerve function recovery was confirmed to be possible with conservative treatment and rehabilitation alone. These findings suggest that the nerve function recovery can be expected with conservative treatment, even for severe nerve injury for which microsurgery cannot be considered.

흰쥐 좌골신경에 신경파괴제 주입 후 초래되는 하지 운동과 신경조직학적 변화 (Functional and Histopathological Changes Following Injection of Neurolytic Agents on Rat's Sciatic Nerve)

  • 전재규;송선옥;정성원
    • The Korean Journal of Pain
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    • 제14권1호
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    • pp.83-92
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    • 2001
  • Background: This study was undertaken to observe the functional changes of the hind limb and histopathological changes in the sciatic nerve after an injection of alcohol or phenol, which are commonly used neurolytic agents, highlighting the time of recovery. Methods: Forty-eight Sprague-Dawley rats weighing 200-300 g were used for the experiment. Histopathological changes under the electron microscope, were observed in the distal part of the sciatic nerve, into which 0.1 ml of alcohol or phenol was injected. This was severed in 3 rats of each group at 10 minutes, 1 hour, 24 hours, 3 days, 1, 2, 4 and 6 weeks later. The functional changes in the hind limbs were observed for 6 weeks by noting their walking pattern. Results: Following the injection of alcohol or phenol into the right sciatic nerve, the right hind limb showed a severe pronounced motor weakness and obvious gait changes. About 2 weeks later, gradual improvement of gait changes began, and after 6 weeks, the motor weakness and gait changes were no longer perceptible in both groups. The findings of any histopathological change were similar in both alcohol or phenol groups. At 10 minutes after injection, destructive lesions were confined to the unmyelinated fibers and the myelin sheath of small the myelinated fibers. On the 3rd day and at 1 week, pathologic changes in axonal fibers and Schwann cells were in being phagocytized in spite of myelin restitution. From 2 to 4 weeks, axonal regeneration and remyelination appeared at the same time a myelin disintegration and axonolysis. At 6 weeks, neural regeneration was similar to that of the contralateral control group. Conclusions: These results suggest that functional and histopathological changes, after injection of neurolytics into the peripheral nerves, are quite similar in both alcohol and phenol groups. The progression of functional and histopathological changes become more obvious according to the time interval following the injection. Consequently, side effects that develop following the use of alcohol or phenol may begin to improve around the time that nerve regeneration occurs, i.e., two to four weeks later.

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