• 제목/요약/키워드: radiation graft

검색결과 116건 처리시간 0.022초

Synthesis of arsenic adsorbent using graft polymerization

  • SEKO Noriaki;TAMADA Hasao
    • 한국막학회:학술대회논문집
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    • 한국막학회 2004년도 추계 총회 및 학술발표회
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    • pp.199-203
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    • 2004
  • Fibrous arsenic (As) adsorbent was synthesized by loading zirconium (Zr) on fibrous phosphoric adsorbent that was directly synthesized by radiation-induced graft polymerization of 2-hydroxyethyl methacrylate phosphoric acid on polyethylene-coated polypropylene nonwoven fabric. Zirconium reacted with phosphoric acid grafted in the polyethylene layer. Zirconium density of the resulting adsorbent was 4.1 mmol/g. The breakthrough curve of As(V) adsorption was independent of the flow rate up to $1300\;h^{-1}$ in space velocity. The total capacity of As(V) was 2.0 mmol/g-adsorbent at pH of 2. The adsorbed Zr(IV) could be evaluated by 0.4 M sodium hydroxide solution because negligible Zr(IV) could be found in the eluted solution.

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Radiation-Induced Graft Copolymerization of Acrylic Acid onto Polyester

  • Chang, Hoon-Sean;Kong, Young-Kun;Lee, Chong-Kwang;Park, Jae-Ho
    • Nuclear Engineering and Technology
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    • 제9권2호
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    • pp.65-74
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    • 1977
  • High dose rates꼭 전자선을 이용하여 Polyester 직포에 acrylic acid를 중합 반응시켰다. Homopolymerization inhibitor로서 cation 을 첨가시키면 hoinopolymerization 뿐만 아니라 graft효율도 감소되었다. Graft 중합 반응 속도는 선량율이 1.6$\times$$10^{6}$rad/sec에서부터 10$\times$$10^{6}$ rad/sec 사이에서 선량율의 0.82승에 비례하였다. Acrylic acid가 graft 중합 반응된 Polyester 직포는 흡습성, 제전성 효과 등이 크게 증진되었다.

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방사선 그래프트에 의한 반투막 제조연구 (Preparation of Permselective Membrane by Mean of a Radiation-Induced Grafting)

  • Young Kun Kong;Hoon Seun Chang;Chong Kwang Lee;Jae Ho Choi
    • Nuclear Engineering and Technology
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    • 제15권1호
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    • pp.1-10
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    • 1983
  • Grafting과 주형용액 성분의 조절에 의한 붕괴 반웅과 방사선애 의한 graft 중합의 공간적 변화는 발견되지 않았다. 스틸렌-셀루로즈 아세테이트 grafts의 내절연성은 스틸렌 함량이 증가할수록 증가한 반면 친수성 단량체에 관한 grafts는 확실한 효과를 나타내지 않았다. 동시 조사법에 의해 graft된 셀루로즈 아세테이트막과 비교해 보면 전조사법에 의해 graft된 막은 ${\gamma}$선 또는 전자선의 방사선선량과 graft %에 관계없이 거의 변하지 않았다. VP:St: BPO 시스템내 디비닐벤젠 (DB) 또는 트리메틸프로판트리아크레이트(TMPT) 같은 가교제의 혼합으로 점차 graft %는 증가되었다. 셀루로즈 아세테이트막에 대한 St:VP:BPO 용액의 grafting에 관한 활성화 에너지는 55$^{\circ}$-8$0^{\circ}C$에서 약 21.8Kca1/mole이었다. Grafting의 초기속도 (%/hr)는 선량강도의 0.76 승에 비례하였다.

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Radiation-Induced Graft Copolymerization of Hydrophilic Monomers to Polyester

  • Lee, Chong-Kwang;Park, Jae-Ho
    • Nuclear Engineering and Technology
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    • 제4권2호
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    • pp.90-101
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    • 1972
  • Polyester 직포 표면을 친수화하기 위하여 함침법에 의하여 acrylic acid를 방사선 graft 공중합시켰다. 이때 함침된 직포를 질소에서 Co-60감마선으로 조사하였다. 생성된 Homopolymer는 10$0^{\circ}C$의 물에 의하여 대체로 유출되었다. Graft된 직포는 산성, 염기성 또는 분산염료에 대하여 재래식 저온 침염법에 의해서 염색이 잘 되었다.

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Hemodynamic Consideration for Endoleak and Aneurysm Size Change after the Stent-Graft Application of Aortic Aneurysm

  • Park, Jea-Hyung;Jae, Hwan-Joon;Lee, Whal;Chung, Jin-Wook
    • International Journal of Vascular Biomedical Engineering
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    • 제2권2호
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    • pp.10-15
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    • 2004
  • Purpose: In the treatment of aortic aneurysm, endovascular stent-graft application has become an established method of treatment. To observe the outcomes of the procedure as the size change of aneurysm in relation with endoleak, a retrospective analysis was done for the consecutive cases who undertook the procedure. Materials & Method: Stent-graft was applied to the aortic aneurysm in 33 patients. The location of the aneurysm was thoracic in 11 patients and abdominal in 22 patients. CT angiographic was done for the follow-up evaluation to analyze the aneurysm size and the presence of endoleak. Results: Technical success rate was 97% (32/33). The primary success rate without endoleak was 84% (28/33). The secondary success was 90% (30/33). During the follow-up period of 3 months to 7years and 6months in 26 patients, a secondary endoleak developed in 5 cases. Post-implantation syndrome developed in 17 cases (51%). Among the 14 cases with follow-up imaging data for size, endoleak was negative in 10 cases. The aneurysm decreased in 5 cases, stable in size in 4 cases and enlarged in one case (10%).Among the 4 cases with endoleak positive, the aneurysm enlarged in two cases (50%). Conclusion: In the stent-graft application for aortic aneurysm, there is high chance of decrease of aneurysm size in those cases with endoleak negative. However, the aneurysm may increase and eventually rupture in the cases with en do leak positive. Close observation with CT angiography is necessary for the evaluation for the presence of endoleak and size change.

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Tyrosinase-Immobilized Biosensor Based on Ionic Property-Modified MWNTs Prepared by Radiation-Induced Graft Polymerization

  • Ryu, Ha-Na;Choi, Seong-Ho
    • Carbon letters
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    • 제11권3호
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    • pp.216-223
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    • 2010
  • Two-types of ionically modified multi-walled carbon nanotube (MWNTs) based sensors were developed by radiationinduced graft polymerization using vinyl monomers such as 3-(butyl imidazol)-2-(hydroxyl)propyl methyl methacrylate and 1-[(4-ethenylphenyl)methyl]-3-buthyl-imidazolium chloride with ionic properties, in aqueous solution at room temperature. Subsequently, the tyrosinase-immobilized biosensor was fabricated by a hand-casting of the ionic property-modified MWNTs, tyrosinase, and chitosan solution as a binder onto ITO glass surface. The sensing ranges of the tyrosinase-biosensor for phenol in phosphate buffer solution was in the range of 0.005~0.2 mM. The total phenolic compounds mainly such as caffeine of the tyrosinase-immobilized biosensor for commercial coffee were also determined.

Radiation-Induced Graft Copolymerization of Hydrophilic Monomer onto Nylon 6

  • Choi, Jae-Ho;Lee, Chong-Kwang;Lee, Kwang-Jin
    • Nuclear Engineering and Technology
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    • 제6권3호
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    • pp.161-169
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    • 1974
  • Nylon직포의 표면을 친수화 하기 위하여 동시조사법으로 Acrylic acid를 방사선 graft중합시켰다. Monomer용액속서 침지된 Nylon직포를 공기중 또는 진공하에서 ${\gamma}$-선으로 조사시켰다. 직포 표면에 형성된 Polyacrylic acid는 10$0^{\circ}C$의 sodium hydroxide용액(0.1%)으로 대부분 추출되었다. 접목 반응된 생성물의 화학적 조성을 측정하였다. 접목반응된 Polymer와 방사선 처리를 하지 않은 polyamide를 비교하여 볼 때 흡수성이라든가 대전성은 증진되었다.

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Solitary Keratoacanthoma at the Recipient Site of a Full-Thickness Skin Graft: A Case Report and Review of the Literature

  • Jeong Ho Kim;Sang-Hoon Lee;Seung-Phil Hong;Jiye Kim;Sug Won Kim
    • Archives of Plastic Surgery
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    • 제50권1호
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    • pp.59-62
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    • 2023
  • A 57-year-old man presented with a pigmented papule, 0.4 cm in diameter, on the left lower eyelid. Skin biopsy revealed a basal cell carcinoma, which was excised through a wide excision followed by a full-thickness skin graft (FTSG). Two weeks after the surgery, an erythematous nodule developed in the lower margin of the graft recipient site. The nodule size increased rapidly over 2 weeks, becoming dome-shaped with a central hyperkeratotic plug. A diagnosis of keratoacanthoma (KA) was made, and surgical excision was performed. Histological findings revealed a large, well-differentiated squamous tumor with a central keratin-filled crater and buttress. The human papilloma virus (HPV) genotyping results were negative. Risk factors for KA include trauma, old age, exposure to ultraviolet (UV) radiation, immunosuppression, and HPV infection. KA has most often been reported to develop at the donor site. Although the pathogenesis of KA is unclear, trauma is believed to act as a second insult to a preceding oncogenic insult, such as exposure to UV radiation, resulting in a koebnerization. Herein, we report a case of solitary KA at a FTSG recipient site. This report presents information that may provide guidance during dermatologic surgeries.

Failed septal extension graft in a patient with a history of radiotherapy

  • Kang, Il Gyu;Kim, Seon Tae;Lee, Seok Ho;Baek, Min Kwan
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제38권
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    • pp.40.1-40.4
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    • 2016
  • Background: This report describes the authors' experience of "melting" septal cartilage after placement of a septal extension graft in a nasopharyngeal cancer patient that had been previously undergone radiation therapy, and provides a review of the literature. Methods: Electronic medical records were used to obtain details of the patient's clinical history. Results: A 32-year-old woman, who had previously undergone radiotherapy for nasopharyngeal cancer, visited our department to for rhinoplasty. Rhinoplasty was performed using a septal extension graft to raise the nasal tip (first operation). Five days after surgery, it was found that the septal extension graft was melting without any signs of infection, that is, the graft had softened, lost elasticity, thinned, and partially disappeared without any sign of infection at 5 days, and thus, the nasal tip was reconstructed with conchal cartilage (second operation). Five months after surgery, it was found that almost all septal cartilage had disappeared without any sign of infection, and thus, the entire nasal septum was reconstructed using 2-mm costal cartilage and an onlay graft was used for tip augmentation (third operation). Conclusions: After cartilage has been exposed to radiotherapy, its patency should be viewed with suspicion. Further studies are needed for determine the mechanism responsible for cartilage damage after radiotherapy.