• Title/Summary/Keyword: Grafting

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Synthesis of Poly(MMA-co-PEGMA) Electrolytes by Grafting-onto Method and Effect of Composition on Ionic Conductivities (Grafting-onto법에 의한 poly(MMA-co-PEGMA) 전해질의 합성과 이온전도도에 대한 조성의 영향)

  • Lee, Ju-Hyung;Ryu, Sang-Woog
    • Journal of the Korean Electrochemical Society
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    • v.16 no.4
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    • pp.198-203
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    • 2013
  • Copolymer consisted of MMA and tBMA was synthesized by radical polymerization and poly(MMA-co-MA) was prepared by selective hydrolysis of tert-butyl group. The obtained polymer was coupled with epoxy functionalized PEO of various molecular weight to synthesize poly(MMA-co-PEGMA) with different side chain length. The AC-impedance measurement shows $1.88{\times}10^{-6}Scm^{-1}$ of room temperature ionic conductivity from 48mol% of MMA while $5.11{\times}10^{-8}Scm^{-1}$ was observed in 82mol% sample. In addition, there was an effect of PEGMA molecular weight on ionic conductivity possibly due to the steric hindrance in grafting-onto coupling reaction. Finally, the polymer electrolytes shows electrochemical stability up to 6V at room temperature.

A Study on the Graft Distribution of the FEP-g-PSSA Membranes Prepared by a Simultaneous Irradiation Method (방사선 동시조사법에 의해 제조된 FEP-g-PSSA 막의 그래프트 분포에 관한 연구)

  • Ko, Beom-Seok;Shin, Jun-Hwa;Sohn, Joon-Yong;Nho, Young-Chang;Kang, Phil-Hyun
    • Polymer(Korea)
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    • v.33 no.3
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    • pp.268-271
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    • 2009
  • In this study, the distribution behaviors of the polystyrene sulfonic acid (PSSA) grafting polymer across the FEP-g-PSSA membranes prepared by a simultaneous irradiation method, were investigated by analyzing the cross-section of the membranes with a SEM-EDX instrument. The effects of irradiation conditions such as the degree of grafting, FEP film thickness, and grafting solvent on the distribution of the grafting polymer were mainly studied in this experiment. The results indicate that to obtain the evenly grafted FEP-g-PSSA membranes, the higher degree of grafting is required as the film thickness increases, and the lower dose rate are more effective than the higher dose rate at the given dose.

A Prognosis Evaluation after Iliac Bone Graft in Cleft Alveolus Patients (치조열 환자의 장골이식술 후 예후 평가)

  • Hong Jin-Ho;Soh Byung-Soo;Baik Jin-Ah;Shin Hyo-Keun
    • Korean Journal of Cleft Lip And Palate
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    • v.4 no.2
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    • pp.69-78
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    • 2001
  • Alveolar cleft exists in 75% of cleft patients, In alveolar cleft patients, alar base is widening, palatal fistular formation, maxillary growth disturbance & tooth loss of adjacent area is raised, Alveolar bone grafting, especially iliac bone grafting, is a general treatment method. As operation timing, bone grafting is classified with primary, early secondary, secondary, & late secondary, Here we report cleft width, marginal bone height, bone resorption rate, grafted shape & bone densities after secondary iliac bone grafting was done in the Dept. of oral and maxillofacial surgery of chonbuk national university hospital. We compared cleft width to bone resorption rate and grafted shape. Also, alveolar bone densities of grafted and contralateral site was compared with Emago 3 package? (Oral Diagonostic System, The Netherlands), The data obtained were analyzed using Spearman's rho coefficients and sign test with SPSS for window, The results were obtained as follows. 1. As alveolar cleft width is increase, bone resorption rate is, too. This relation showed significant difference(P<.01). 2, In proximal & distal area, alvolar cleft width and bone graft contour after bone grafting had a reverse proportional difference. It was not significant difference(P>.05). 3. After 3 month, in bone density results by using Emago 3 package? with periapical standard view, occlusal view & panoramic view, differences between grafted bone and alveolar bone of contralateral site didn't show a significant difference(P>.05). Thus, differences of bone densities in the alveolar bones didn't exist.

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Studies on Adhesion Properties of Grafted EPDM Containing Carboxylic Acid Group (카르복시산을 포함하는 Grafted EPDM의 접착특성에 관한 연구)

  • Kim, Dongho;Yoon, Yoomi;Chung, Ildoo;Park, Chanyoung;Bae, Jongwoo;Oh, Sangtaek;Kim, Guni
    • Journal of Adhesion and Interface
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    • v.13 no.1
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    • pp.1-8
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    • 2012
  • The effect of the grafting ratio on the mechanical property and adhesion property of the grafted EPDM modified with methacrylic acid (MA) was investigated. The storage modulus of MA-grafted EPDM was maintained higher than that of cross-linked EPDM vulcanizate by sulfur, but it was observed that the storage modulus was decreased at elevated temperature because of the weakened secondary bonding. When the functional group for hydrogen bonding was introduced in EPDM, it had excellent mechanical properties by the aggregate between grafted EPDM molecules and crystallinity of MA. The bonding strength between EPDM and other rubbers was very low because EPDM has nonpolar property and low molecular interaction to others. The bonding strength was increased as increasing grafting ratio and it was excellent enough to break the rubber during the peel test when the grafting ratio was more than 10%.

Effect of Grafting Cultivation on the Growth of Hot Pepper (고추 접목재배가 생육에 미치는 영향)

  • Kim Eun-Hyun;Kim Hak-Jin;Kwon Byung-Sun;Lim June-Taeg;Hyun Kyu-Hwan;Kim Do-Young;Shin Dong-Young
    • Korean Journal of Plant Resources
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    • v.18 no.1
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    • pp.78-84
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    • 2005
  • Charactertistics of growth from graft induced three stock of red pepper cultivar were analysed. R-safe rootstock was more higher and vigorous than that of the Yeok kang, Konesian hot cultivar at seedling stage and had good characteristics for grafting in the space of cut surface and the amount of sap released. Numbers of branches were more numerous in the grafted plants than those of non-grafted as grafting affected their growths in the process of branching. There was no distinct difference in plant height among the different rootstock. However the R-safe rootstock showed considerably high growth in the 41st days after grafting. Grafting was effective in the early flowering and the R-safe was the earliest in flowering because of it's good growth under the low temperature.

Autogenous fat grafting for mild-to-moderate postoperative temporal hollowing after decompressive craniectomy: One-year follow-up

  • Choi, Jaemin;Choi, Hyungon;Shin, Donghyeok;Kim, Jeenam;Lee, Myungchul;Kim, Soonheum;Jo, Dongin;Kim, Cheolkeun
    • Archives of Plastic Surgery
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    • v.45 no.1
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    • pp.69-73
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    • 2018
  • Background Temporal hollowing is inevitable after decompressive craniectomy. This complication affects self-perception and quality of life, and various techniques and materials have therefore been used to restore patients' confidence. Autologous fat grafting in postoperative scar tissue has been considered challenging because of the hostile tissue environment. However, in this study, we demonstrate that autologous fat grafting can be a simple and safe treatment of choice, even for postoperative depressed temporal scar tissue. Methods Autologous fat grafting was performed in 13 patients from 2011 to 2016. Fat was harvested according to Coleman's strategy, using a tumescent technique. Patient-reported outcomes were collected preoperatively and at 1-month and 1-year follow-ups. Photographs were taken at each visit. Results The thighs were the donor site in all cases for the first procedure. The median final volume of harvested fat was 29.4 mL (interquartile range [IQR], 24.0-32.8 mL). The median final volume of fat transferred into the temporal area was 4.9 mL on the right side (IQR, 2.5-7.1 mL) and 4.6 mL on the left side (IQR, 3.7-5.9 mL). There were no major complications. The patient-reported outcomes showed significantly improved self-perceptions at 1 month and at 1 year. Conclusions Despite concerns about the survival of grafted fat in scar tissue, we advise autologous fat grafting for patients with temporal hollowing resulting from a previous craniectomy.

Emulsion Grafting of Glycidyl Methacrylate onto Plasma-treated Polypropylene Surface (플라즈마 처리된 폴리프로필렌 표면 위에 글리시딜메타크릴레이트의 에멀젼 그래프팅)

  • Ji, Han-Sol;Liu, Xuyan;Choi, Ho-Suk;Kim, Jae-Ha;Park, Han-Oh
    • Polymer(Korea)
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    • v.36 no.1
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    • pp.65-70
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    • 2012
  • Glycidyl methacrylate (GMA) was used to introduce epoxy groups on the surface of polypropylene (PP) plate, used as a substrate, through plasma-induced graft copolymerization. Emulsion polymerization was applied for graft copolymerization of GMA and was compared with conventional solution polymerization to confirm its effect. Plasma treatment conditions under one atmospheric pressure were fixed as follows; the RF power of 200 W, the treatment time of 30 sec, the Ar gas flow rate of 6 LPM, and the exposure time of treated PP samples in air of 5 min. For graft-copolymerization, GMA concentration, reaction temperature, and reaction time was optimized to maximize the grafting degree of GMA. The maximum grafting degree of GMA was obtained at the condition of 12%-GMA concentration, $90^{\circ}C$ reaction temperature, and 5 hr-reaction time. Analysis results supported that the emulsion polymerization was more effective than the solution polymerization for grafting more GMAs on the surface of PP plate under the same reaction conditions.

A Cross-Sectional Analysis of Breast Reconstruction with Fat Grafting Content on TikTok

  • Gupta, Rohun;John, Jithin;Gupta, Monik;Haq, Misha;Peshel, Emanuela;Boudiab, Elizabeth;Shaheen, Kenneth;Chaiyasate, Kongkrit
    • Archives of Plastic Surgery
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    • v.49 no.5
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    • pp.614-616
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    • 2022
  • As of November 2021, TikTok has one billion monthly active users and is recognized as the most engaging social media platform. TikTok has seen a surge in users and content creators, ranging from athletes to medical professionals. In the past year, content creators have utilized the app to advocate for social reforms, education, and other uses that were not previously considered. Breast cancer is the most commonly diagnosed cancer in women, with an expected 281,550 new cases of invasive breast cancer in 2021. As more individuals with breast cancer choose to undergo resection, the demand for autologous fat grafting in breast reconstruction has increased due to the natural look and feel of breast tissue. The purpose of this article is to analyze content related to breast reconstruction with fat grafting found on TikTok and recommend methods to improve patient education, care, and outcomes. We searched TikTok on November 1, 2021, for videos using the phrase "breast reconstruction with fat grafting." The top 200 videos retrieved from the TikTok search algorithm were analyzed, and all commentaries, duplicates, and nonrelevant videos were removed. Video characteristics were collected, and two independent reviewers generated a DISCERN score A total of 131 videos were included in the study. They were found to have a combined 1,871,980 likes, 41,113 comments, and 58,662 shares. The videos had an average DISCERN score of 2.16. Content creators had an overall low DISCERN score in items involving the use of references, disclosure of risks for not obtaining treatment, and support for shared decision-making. When stratified, the DISCERN score was higher for videos created by physicians (DISCERN average 2.48) than for videos created by nonphysicians (DISCERN average 1.99; p < 0.001).

Polymer brush: a promising grafting approach to scaffolds for tissue engineering

  • Kim, Woonjung;Jung, Jongjin
    • BMB Reports
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    • v.49 no.12
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    • pp.655-661
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    • 2016
  • Polymer brush is a soft material unit tethered covalently on the surface of scaffolds. It can induce functional and structural modification of a substrate's properties. Such surface coating approach has attracted special attentions in the fields of stem cell biology, tissue engineering, and regenerative medicine due to facile fabrication, usability of various polymers, extracellular matrix (ECM)-like structural features, and in vivo stability. Here, we summarized polymer brush-based grafting approaches comparing self-assembled monolayer (SAM)-based coating method, in addition to physico-chemical characterization techniques for surfaces such as wettability, stiffness/elasticity, roughness, and chemical composition that can affect cell adhesion, differentiation, and proliferation. We also reviewed recent advancements in cell biological applications of polymer brushes by focusing on stem cell differentiation and 3D supports/implants for tissue formation. Understanding cell behaviors on polymer brushes in the scale of nanometer length can contribute to systematic understandings of cellular responses at the interface of polymers and scaffolds and their simultaneous effects on cell behaviors for promising platform designs.

EVAPOTRANSPIRATION RATE AND GRAFT-TAKING OF GRAFTED SEEDLINGS UNDER ARTIFICIAL LIGHTING

  • Kim, Y. H.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2000.11c
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    • pp.632-638
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    • 2000
  • This paper represents the characteristics of evapotranspiration rate (EVTR) and graft-taking of watermelon grafted seedlings in a graft-taking enhancement system using fluorescent lamps as artificial lighting source. Four air temperature levels of 23, 25, 27 and 29C, three humidity levels of 85, 90 and 95%R.H. and two photosynthetic photon flux (PPF) levels of 30 and 50 ${\mu}$mol m$\^$-2/ S$\^$-1/ were provided to investigate the effects of air temperature, relative humidity and light intensity on EVTR and graft-taking of grafted seedlings. EVTR of grafted seedlings increased with increasing air temperature and the passage of time after grafting. Also EVTR increased with decreasing relative humidity. As relative humidity decreased and air temperature increased, vapor pressure deficit increased and thus EVTR increased. It is required to maintain a low level vapor pressure deficit for suppressing EVTR of grafted seedlings during first 1-2 days after grafting. Therefore, less EVTR at initial stage after grafting would be adequate for smooth joining of the scion and rootstock.

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