• Journal of Yeungnam Medical Science
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• 제32권2호
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• pp.138-142
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• 2015

L-thyroxine (LT4) withdrawal prior to radioactive iodine (RAI) ablation therapy is a commonly used method for successful treatment of patients with papillary thyroid cancer (PTC). However, a prolonged period of hypothyroidism induced by LT4 withdrawal is sometimes associated with impaired quality of life and cardiopulmonary dysfunction in PTC patients. Furthermore, LT4 withdrawal may have a trophic effect on residual cancer by means of increased thyrotropin. We report on 2 cases of metastatic PTC patients with malignant pleural effusion (MPE) whose disease showed rapid worsening after LT4 withdrawal and RAI therapy. The first case is a 65-year-old woman who had PTC with multiple distant metastases and MPE. During LT4 withdrawal for RAI therapy, MPE showed rapid worsening, and the patient required repetitive therapeutic thoracentesis. The second case is a 49-year-old woman with PTC who underwent 3 additional operations for cancer recurrence in the neck lymph nodes and 6 times of RAI treatments. While preparing for the $7^{th}$ RAI treatment by withdrawing LT4, she developed MPE which became progressively aggravated after RAI therapy. Both patients experienced increased pleural effusion during the LT4 withdrawal period and a rise in the thyroglobulin level was observed after RAI therapy. MPE was not controlled with therapeutic thoracentesis and pleurodesis. Eventually, both patients died of rapid disease progression after RAI therapy. In summary, LT4 withdrawal may have an adverse effect on metastatic PTC patients, particularly those with MPE.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.83.1-83
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• 2002

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.83.2-83
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• 2002

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.84.1-84
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• 2002

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.85.1-85
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• 2002

• 한국세라믹학회지
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• 제33권11호
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• pp.1231-1236
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• 1996

The electrode resistance of semiconducting PTC BaTiO3 ceramic material was studied in some detail. Comme-rical In-Ag paste In-Ga alloy and electroless plated Ni as well as evaporated Al were chosen as electrode. The contact resistance of electroded samples were measured by both dc resistivity and ac impedance analysis. The aging effect on contact resistance under cyclic loading from -1$0^{\circ}C$ to 85$^{\circ}C$ was also monitored for the prolonged period of time. In case of Al electroded samples the heat treatment and protective coating had effects on the stability against contact resistance degradation. It was also found that the samples with commercial In-Ag paste and electroless plated Ni electrode had good properties of contact resistance against aging.

• 한국세라믹학회지
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• 제28권2호
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• pp.101-108
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• 1991

0.2 mo1% La doped BaTiO3 samples were prepared by a wet chemical process (Pechini process) and electrical conductivity were measured from annealing temperatures(800-110$0^{\circ}C$) to room temperature continuously. 2 probe I-V characteristics showed that Pt electrodes were non-ohmic below about 80$0^{\circ}C$ for Ladoped sample. I-V curves showed varistor behavior and breakdown voltages showed PTC-like behavior. AC complex impedance of 0.2 La and 0.05 Mn mo1% doped BaTiO3 samples with three different electrodes (electroless Ni, Pt, Ag electrodes) were measured with temperature variation. Complex impedance plots showed that the samples with electroless Ni electrodes have negligible electrode resistance. Samples with Ag or Pt paste electrodes showed large electrode resistance. PTC effect, which is defined as the ratio of maximum resistance to minimum resistance, was found to be less than 10 for 0.2 mo1% La doped dense sample however greater than 105 with codoping of 0.05 mo1% Mn and 0.2 mol% La.

• Carbon letters
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• 제1권1호
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• pp.1-5
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• 2000

The effect of surface free energy on the positive temperature coefficient (PTC) of carbon black/thermoplastic resin composites was investigated. The thermoplastic resins such as EVA, LDPE, LLDPE and HDPE were used with the addition of 30 wt.% of the carbon black. The surface free energy of the composites was studied in the context of two-liquid contact angle measurements, i.e., deionized water and diiodomethane. It was observed that the resistivity on PTC composites Was greatly increased near the crystalline melting temperature, due to the thermal expansion of polymeric matrix. From the experimental results, it was proposed that the decrease of surface free energy induced by interactions between carbon black surfaces and polymer chains is an important factor to the fabrication of a PTC composite made of carbon black and polymeric matrix.

• E2M - 전기 전자와 첨단 소재
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• 제8권1호
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• pp.83-89
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• 1995

In this paper, the specimens-($Ba_{0.997}$ L $a_{0.003}$)Ti $O_{3}$ + xTi $O_{2}$, x=0.005, 0.01, 0.02, 0.03[mol]- were fabricated by a solid-state reaction method which is easy in microstructure control and good in mass production. Their crystalline structures and microstructures were analysed, and electrical properties were investigated. The perovskite-crystalline structure is confirmed by XRD, and it is exhibited by SEM that the grain grows with an addition of Ti $O_{2}$. Resistivity decreases with increasing sinteiing temperature, and the specimen of ($Ba_{0.997}$ L $a_{0.003}$)Ti $O_{3}$ + 0.02Ti $O_{2}$ sintered at 1350.deg. C shows the best PTC effects. The complex impedance plots exhibit the serial equivalent circuit of ( $R_{gb}$ / $C_{gb}$ ) and $R_{g}$ it is realized that PTC effect is attributed to the resistivity of grain boundary.ary.y.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.179-179
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• 2008

$BaTiO_3$를 기본조성으로 하는 PTC 써미스터는 Curie 온도이상에서 저항이 급격히 상승하는 산화물 반도체 세라믹이다. 이러한 성질을 이용하여 degaussing 소자, 정온 발열체, 온도센서, 전류 제한소자 등 상업적으로 여러 분야에서 연구되고 있다. 또한 원가절감 등을 위하여 Ni 내부전극을 사용하여 환원 분위기에서 소결하는 칩 타입에 대한 연구가 진행되고 있다. 본 연구에서는 Sm 함량(0.1at%~1.0at%)을 달리한 $BaTiO_3$(Si, Mn, Ca) 계를 선택하여 3%$H_2/N_2$ 분위기에서 1200~$1260^{\circ}C$, 2h 소결한 후 공기 중에서 재산화 처리하고 재산화 시간에 따른 PTC 특성 변화에 대하여 고찰하였다. 재산화 온도와 시간은 각각 $800^{\circ}C$와 0.5h~10h으로 하였다. Sm 함량을 달리하여 환원 분위기에서 소결한 시편의 미세구조와 PTC 특성과의 상관관계를 관찰한 결과, 소결온도가 낮을수록 PTC 특성은 좋아졌으며, 상온 비저항은 Sm 함량이 높아질수록 낮아졌다. 또한 Sm 함량이 높아질수록 jumping ratio$(R_{max}/R_{25^{\circ}C})$는 낮아졌다. 재산화 시간에 따른 PTC 특성은 다소 떨어졌지만 소결온도에 따라 달리 나타났다. Jumping ratio$(R_{max}/R_{25^{\circ}C})$는 Sm을 0.7 at% 첨가한 계에서 재산화를 1시간 처리한 시편에서 가장 우수하였다.