• 통합자연과학논문집
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• 제6권2호
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• pp.82-86
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• 2013

This paper describes a method for the preparation of porous polymethylmethacrylate showing optical reflectivity from the porous silicon template. A porous polymethylmethacrylate showing optical reflectivity was prepared by replicating porous silicon template which was obtained by applying a computer-generated periodic square current density and resulted in a mirror with high reflectivity in a specific narrow spectral region. A porous polymethylmethacrylate showing an excellent reflectivity was successfully obtained by dissolving the Porous silicon template from the porous polymethylmethacrylate composite film. A porous polymethylmethacrylate exhibited a sharp reflection resonance in the reflectivity spectrum. Surface image of the porous polymethylmethacrylate indicated that the surface of the porous polymethylmethacrylate film had a porous structure. These porous polymethylmethacrylate films in aqueous solutions were stable for several days without any degradation.

• 대한골관절종양학회지
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• 제5권1호
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• pp.23-28
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• 1999

Between Sep. 1986 and Mar. 1996, twenty four patients with recurrent giant cell tumor of their long bones were treated and followed up for more than two years. We applied three different modalities for treatment: curettage with bone graft, curettage and packing with polymethylmethacrylate, wide excision with or without reconstruction. During the average 51.5 months after operation(24-97 months), two of three patients who underwent curettage with bone graft showed recurrence. Patients who underwent wide excision showed no recurrence. Five of fifteen patients who underwent curettage and packing with polymethylmethacrylate showed recurrence. Four of seven who showed recurrence were treated with reapplication of curettage and packing with polymethylmethacrylate. All four patients showed no recurrence, and two of them have been followed up for more than two years. We suggest that the curettage and packing with polymethylmethacrylate is an effective treatment modality of the recurrent giant cell tumor.

• 한국안전학회지
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• 제12권4호
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• pp.79-85
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• 1997

In order to improve the surface characteristics of polymethylmethacrylate(PMMA), oxide thin film coatings were applied using the sol-gel dip-coating technique. The $Si(OC_2H_5)_4$, tetra-ethyl-ortho-silicate(TEOS) was used as a starting material for $SiO_2$ coating. The hardness of the alkoxy-derived oxide-coated PMMA was increased from 190 MPa for non-coated PMMA with increasing film thickness. By optimizing the heating conditions and the hydrolysis conditions, a maximum apparent hardness obtained In the present study was achieved 310 MPa using the withdrawal velocity of 5cm/min and heat treatment at $90^{\circ}C$ for 5 hours, which is about 1.6 times larger than that of uncoated PMMA.

• Transactions on Electrical and Electronic Materials
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• 제17권4호
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• pp.204-207
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• 2016

Experimental study of UV-irradiated O₂/H₂ gas phase cleaning for PMMA (Polymethylmethacrylate) removal is carried out in a load-locked reactor equipped with a UV lamp and PBN heater. UV enhanced O₂/H₂ gas phase cleaning removes polymethylmethacrylate (PMMA) better at lower process pressure with higher content of H₂. O₂ gas compete for UV (184.9 nm) absorption with PMMA producing O₃, O(¹D) and lower dissociation of PMMA. In our experimental conditions, etching reaction of PMMA at the substrate temperature between 75℃ and 125℃ had activation energy of about 5.86 kcal/mol indicating etching was controlled by surface reaction. Above the 180℃, PMMA removal was governed by a supply of reaction gas rather than by substrate temperature.

• Tuberculosis and Respiratory Diseases
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• 제61권2호
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• pp.184-188
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• 2006

경피적 척추성형술은 PMMA를 붕괴된 척추체에 경피적으로 주사하여 통증을 완화시키고 척추체를 구조적으로 보강하는 시술이다. 척추성형술은 아주 효과적인 치료방법이기는 하나 합병증이 전혀 없지는 않다. 척추성형술의 많은 합병증은 주로 PMMA 누출과 관련되어 있다. 대부분의 누출은 증상이 없고 또한 폐색전증은 매우 드물지만 시술도중 PMMA의 혈관내 이동을 조기에 발견하지 못할 때 발생할 수 있다. 저자들은 천식으로 인한 기침으로 내원한 환자의 흉부X선에서 우연히 PMMA에 의한 폐색전증을 진단하였기에 문헌 고찰과 함께 보고하는 바이다.

• 분석과학
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• 제19권6호
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• pp.468-472
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• 2006

기능성 화장품 원료로서 관심을 갖는 비타민 C(L-ascobic acid)는 피부에 대한 안전성, 항산화성으로 인해 노화방지 및 미백, 잔주름개선 등의 효능을 갖지만 화학적으로 쉽게 산화된다. 따라서 본 연구에서는 비타민 C의 안정성에 대한 단점을 보완하기 위하여, 에멀젼 중합법으로 다양한 마이크론 크기의 Polymethylmethacrylate(PMMA)입자를 제조하고, 제조된 PMMA의 입자 표면에 코팅용액(물과 에탄올 혼합용매에 cyclodextrin과 비타민 C를 녹인 용액)을 이용하여 비타민 C를 코팅처리 하였다. 코팅처리 후, 실온 및 $40^{\circ}C$에서 시간에 따른 비타민 C의 함량을 조사한 결과, 56일이 경과후에도 비타민 C가 86.4%가 잔존함을 확인 할 수 있었다.

• The Korean Journal of Pain
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• 제13권1호
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• pp.126-129
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• 2000

Age-related osteoporotic compression fractures occur frequently in old aged group recently. Percutaneous vertebroplasty has recently been introduced as a therapeutic method for the treatment of pain associated with osteoporotic vertebral compression fracture. Percutaneous intravertebral injection of PMMA (polymethylmethacrylate) results in marked reduction in pain and morbidity. Among complications during vertebroplasty with PMMA, pulmonary embolism is repotred occasionally but the reports about hypotension are not common. This case is a report of a patient whom significant hypotension occured during percutaneous vertebroplasty.

• Fibers and Polymers
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• 제5권3호
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• pp.239-244
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• 2004

Solution-cast films of polymethylmethacrylate (PMMA) and polyurethane (PU) containing polymeric styryl dye up to 5 % by weight were prepared to investigate their acid-sensitivity and mechanical and thermal properties. Original red samples due to styryl dye turned out yellow very rapidly as they were exposed to acid vapor of hydrochloric acid or p-toluenesulfonic acid. According to UV/VIS spectroscopic measurements, characteristic peak intensities near 430 nm and 520 nm increased or decreased relatively with exposed amounts of acid, respectively. Both PMMA and PU samples showed uniform color distribution due to a good miscibility between polymer and dye which can be evidenced by measurements of glass transition temperature. No significant difference in acid-sensitivity was found between PU and PMMA except relative absorbance. However, dependence of their mechanical properties on dye content was somewhat different with PU or PMMA. In case of PMMA, modulus and breaking stress increased up to about 50 % with increasing dye content, whereas those of PU samples showed only slight increase. It was ascribed to whether the matrix polymer was in the glassy or rubbery state.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1990년도 제1차 학술발표초록집
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• pp.25-26
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• 1990

• Journal of Korean Neurosurgical Society
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• 제55권3호
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• pp.167-169
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• 2014

Giant cell tumor (GCT) of the spine is a rare benign tumor, but can be aggressive and can exhibit a high local recurrence rate. Furthermore, GCT of the upper thoracic spine may pose diagnostic and management difficulties. Here, we report a rare case of GCT of the upper thoracic spine with soft tissue extension to the spinal canal. The patient was managed by decompressive laminectomy and posterolateral fusion followed by an injection of polymethylmethacrylate into the vertebral lesion. The patient recovered clinically and showed radiological improvement after surgical treatment without tumor recurrence at his last follow-up of postoperative 7 years. We present this unusual case of GCT and include a review of the literature.