• The Journal of Korean Society for Radiation Therapy
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• v.18 no.2
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• pp.113-117
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• 2006

Purpose: Post-mastectomy radiotherapy (PMR) is known to decrease loco-regional recurrence. Adequate skin and dermal dose are achieved by adding bolus. The more difficult clinical issue is determining the necessary number of bolus treatment, given the limits of normal skin tolerance. The aim of this study is to evaluate the necessary number of bolus treatment after PMR in patients with breast cancer. Materials and Methods: Four female breast cancer patients were included in the study. The median age was 53 years(range, $38{\sim}74$), tumor were left sided in 2 patients and right sided in 2patients. All patients were treated with postoperative radiotherapy after MRM. Radiotherapy was delivered to the chest wall (C.W) and supraclavicular lymph nodes (SCL) using 4 MV X-ray. The total dose was 50 Gy, in 2 Gy fractions (with 5 times a week). CT was peformed for treatment planning, treatment planning was peformed using $ADAC-Pinnacles^3$ (Phillips, USA) for all patients without and with bolus. Bolus treatment plans were generated using image tool (0.5 cm of thickness and 6 cm of width). Dose distribution was analyzed and the increased skin dose rate in the build-up region was computed and the skin dose using TLD-100 chips (Harshaw, USA) was measured. Results: No significant difference was found in dose distribution without and with bolus; C.W coverage was $95{\sim}100%$ of the prescribed dose in both. But, there was remarkable difference in the skin dose to the scar. The skin dose to the scar without and with bolus were $100{\sim}105%\;and\;50{\sim}75%$. The increased skin dose rates in the build-up region for Pt. 1, Pt. 2. Pt. 3 and Pt. 4 were 23.3%, 35.6%, 34.9%, and 41.7%. The results of measured skin dose using TLD-100 chips in the cases without and with bolus were 209.3 cGy and 161.1 cGy, 200 cGy and 150.2 cGy, 211.4 cGy and 160.5 cGy, 198.6 cGy and 155.5 cGy for Pt. 1, Pt. 2, Pt. 3, and Pt. 4. Conclusion: It was concludes through this analysis that the adequate number of bolus treatments is 50-60% of the treatment program. Further, clinical trial is needed to evaluate the benefit and toxicity associated with the use of bolus in PMR.

• Journal of the Korean Ceramic Society
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• v.38 no.1
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• pp.100-105
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• 2001

An all solid-state thin film battery (TFB) was fabricated by growing, undoped and Pt-doped vanadium oxide cathode film ( $V_2$ $O_{5}$ ) on I $n_2$ $O_3$: Sn coated glass, respectively. Room temperature charge-discharge measurements based on Li/Lipon/ $V_2$ $O_{5}$ full-cell structure with a constant current clearly shows that the Pt-doped $V_2$ $O_{5}$ cathode film is superior, in terms of cyclibility. X-ray diffraction (XRD) results indicate that the Pt doping process induces a more random amorphous structure than an undoped $V_2$ $O_{5}$ film. In addition to its modified structure, the Pt-doped $V_2$ $O_{5}$ film has a smoother surface than the undoped sample. Compared to an undoped $V_2$ $O_{5}$ film, the Pt doped $V_2$ $O_{5}$ cathode film has a higher electron conductivity. We hypothesize that the addition of Pt alters electrochemical performance in a manner of making more random amorphous structure and gives an excess electron by replacing the $V^{+5}$. Possible mechanisms are discussed for the observed Pt doping effect on structural and electrochemical properties of vanadium oxide cathode films, which are grown on I $n_2$ $O_3$: Sn coated glass.

• Transactions on Electrical and Electronic Materials
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• v.1 no.3
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• pp.14-17
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• 2000

Giga bit dynamic random access memory(DRAM) requires the capacitor of high dielectric films. Some metal oxides films have been proposed as the dielectric material . And Pt is one of the most promising electrode materials. However very little has been done in developing the etching technologoy Pt film. Therefore, it is the first priority to develop the technology for plasma etching of Pt film. In this study, the dry etching of Pt film was investigated in Inductively Coupled Plasma(ICP) etching system with Cl$_2$/Ar and HBr/Cl$_2$/Ar gas mixing. X-ray photoelectron spectroscopy (XPS) was used in analysis of sidewall residues for the understanding of etching mechanism. We found the etch residues on the pattern sidewall is mainly Pt-Pt, Pt-Cl and Pt-Br compounds, Etch profile was observed by Scanning Electron Spectroscopy(SEM) . The etch rate of Pt film at 10%, Cl$_2$/90% Ar gas mixing ration was higher than at 100%. Ar. Addition of HBr to Cl$_2$/Ar as an etching gas led to generally higher selectivity to SiO$_2$. And the etch residues were reduced at 5% HBr/5% Cl$_2$/90% Ar gas mixing ration. These pages provide you with an examples of the layout and style which we wish you to adopt during the preparation of your paper, Make the width of abstract to be 14cm.

• Nutrition Research and Practice
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• v.16 no.2
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• pp.173-193
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• 2022

BACKGROUND/OBJECTIVES: Alzheimer's disease (AD) is one of the most representative neurodegenerative disease mainly caused by the excessive production of amyloid beta (Aβ). Several studies on the antioxidant activity and protective effects of Populus tomentiglandulosa (PT) against cerebral ischemia-induced neuronal damage have been reported. Based on this background, the present study investigated the protective effects of PT against cognitive impairment in AD. MATERIALS/METHODS: We orally administered PT (50 and 100 mg/kg/day) for 14 days in an Aβ_25-35-induced mouse model and conducted behavioral experiments to test cognitive ability. In addition, we evaluated the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum and measured the production of lipid peroxide, nitric oxide (NO), and reactive oxygen species (ROS) in tissues. RESULTS: PT treatment improved the space perceptive ability in the T-maze test, object cognitive ability in the novel object recognition test, and spatial learning/long-term memory in the Morris water-maze test. Moreover, the levels of AST and ALT were not significantly different among the groups, indicating that PT did not show liver toxicity. Furthermore, administration of PT significantly inhibited the production of lipid peroxide, NO, and ROS in the brain, liver, and kidney, suggesting that PT protected against oxidative stress. CONCLUSIONS: Our study demonstrated that administration of PT improved Aβ_25-35-induced cognitive impairment by regulating oxidative stress. Therefore, we propose that PT could be used as a natural agent for AD improvement.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.1 s.34
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• pp.21-26
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• 2005

The field effect transistors (FETs) were fabricated ell $Y_2O_3/Si(100)$ substrates by the conventional memory processes and sol-gel process using $(Bi,La)Ti_3O_{12}(BLT)$ ferroelectric gate materials. The remnant polarization ($2Pr = Pr^+-Pr^-$) int Pt/BLT/Pt/Si capacitors increased from $22 {\mu}C/cm^2$ to $30{\mu}C/ cm^2$ at 5V as the annealing temperature increased from $700^{\circ}C$ to $750^{\circ}C$. There was no drastic degradation in the polarization values after applying the retention read pulse for $10^{5.5}$ seconds. The capacitance-voltage data of $Pt/BLT/Y_2O_3/Si$ capacitors at 5V input voltage showed that the memory window voltage decreased from 1.4V to 0.6V as the annealing temperature increased from $700^{\circ}C$ to $750^{\circ}C$. The leakage current of the $Pt/BLT/Y_2O_3/Si$ capacitors annealed at $750^{\circ}C$ was about $510^{-8}A/cm^2$ at 5V. From the drain currents versus gate voltages ($V_G$) for $Pt/BLT/Y_2O_3/Si(100)$ FET devices, the memory window voltages increased from 0.3V to 0.8V with increasing tile $V_G$ from 3V to 5V.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.80-80
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• 1998

RU02 박막은 전이금속으로서 rutile 구조이며, 넓은 온도 영역에서 금속성의 를 나타내고, 700도 이상의 높은 온도에서 열적 안정성을 갖는 물질이다 이러한 특성 때문 에 RU02 박막은 실리콘 디바이스에서 배선 게이트 전극 확산 장벽 등에 응용가능성이 높 은 물질로 각광을 받고 있다- 특히 다결정 RU02 박막은 DRAM (dynamic random access m memory) 내의 강유전성 축전기의 전극으로서 유망한 물질이다. 지금까지 이러한 응용분야에 사용된 전극물질은 pt 금속이었다 그러나 이러한 금속전극은 SI 산소 그리고 강유전체의 구성물질 등과의 상호확산, pt 표면의 hillock의 존재로 생기는 전기적 단락, 기판과의 나쁜 점작성, 어려운 에칭 프로세스 등의 단점을 가지고 있다 더욱 더 심각한 문제는 P Pt'ferroelectric/Pt 구조에서 나타나는 aging과 fatigue인데, 이는 108 사이쿨 이후에 스위칭 가 능한 잔류 pOlarization 으$\mid$ 감소를 유발하게 된다- 최근 Berstein은 Pt 대신에 RU02를 사용함으로써 강유전체 축전기에서의 fatigue 현상을 크게 감소시켰다고 보고 한 바 있다 Burst川도 RU02 가 실리콘 표면과 유전체 물질 사이에 전기전도 어떠한 상호 확산도 일어나지 않음을 보였다. 그러나 이러한 연구 결과에도 증착조건과 RU02 박악의 특성에 관한 상호 관계가 충분히 더욱 더 중은 강유전성 박막올 만들기 위해서는 이러한 박막 전극에 않고 있다 연구되지 대한 상세한 연구가 반드시 필요하다고 본다. RU02 박막은 실리콘 기판 위에 고주파 마그네트론 스퍼터링 방법으로 증착하였다. 사용 한 타켓은 2 인치의 직경을 가지는 CERAC 사에서 제작한 Ruol다 초기 진공은 1O~6 Torr 이하였고, 고주파 전력은 20 - 80W 까지 변화시켰다 반응성 스퍼터링율 하기 위해 아르곤과 산소롤 주입하였고, 산소/(산소+아르곤)의 비를 변화시켰다 기판의 온도와 증착압력은 각각 상온에 서 500도까지 , 5mTorr에 서 100mTorr 까지 변 화시 켰 다 RU02 박막의 결정성을 조사하기 위해 XRD 표면 형상과 단면을 조사하기 위해 SEM을 사용하였다‘ 박악의 비저항을 조사하기 위해 4-단자법 van der Pauw 방법을 사용하였다. RU02 박막은 증착압력이 높을수록 비저항은 높아지고, 두께는 감소하였다. 특히 1 100mTorr에서는 작업가스와 스퍼터된 입자사이의 심각한 산란 때문에 아예 증착이 이루어 지지 않았다‘ RF 전력이 증가할수록 비저항이 낮아졌다. 이는 두께에 의존하는 결과이며 전형적인 금속박막에서 나타나는 현상과 유사함을 알 수 있었다- 기판온도와 작업가스의 산소 분압이 높을수록 비저항이 감소하였다‘ 이러한 사실은 성장한 박악의 결정구조와 밀접한 관련이 있음을 보여준다.

• Journal of the Korean Chemical Society
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• v.39 no.1
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• pp.35-39
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• 1995

Simultaneous measurements of trace platinum and rhodium, based on catalytic reduction of protons by the adsorbed Pt-formazone and Rh-formaldehyde complexes formed in formaldehyde-hydrazine-sulfuric acid medium, were demonstrated. The conditions for the measurements of Pt and Rh both present at trace levels (>10-10 M) were 0.004% (w/v) formaldehyde-0.0012% (w/v) hydrazine-0.75 M sulfuric acid. In this medium method detection limits are 7.3${\times}$10-11 M Pt and 3.2${\times}$10-11 M Rh. And dynamic ranges are 5${\times}$10-10~6${\times}$10-8 M and 1${\times}$10-10∼2${\times}$10-8 M for platinum and rhodium respectively. In the linear dynamic ranges, Rh and Ir interfere platinum in the presence of only 10 and 100 times that of Pt respectively. There are no interferences from other platinum group metal ions for rhodium even in the presence of a 500-fold excess of Ir(IV), a hundredfold excess of platinum.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.861-868
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• 1996

Skeletal isomerization reaction known as exothermic reaction shows possible maximum yield of i-butene from n-butene at $110^{\circ}C$ over $Pt/MoO_3/SiO_2$. Compared with conventional catalyst such as silica, zeolite, alumina etc., $Pt/MoO_3/SiO_2$ demonstrates higher yield while by-products except 2-butene do not form. Faster H spillover rate over $Pt/MoO_3/SiO_2$ is demonstrated via isothermal reduction experiment at $110^{\circ}C$ compared to the rate over $Pt/MoO_3/Al_2O_3$. Overall isomerization rates are proportional to higher spillover rates from Pt onto $MoO_3$ surface. The skeletal isomerization reaction is composed of two elementary steps. First, carbonium ion formation over Pt crystallites by H spillover. Second, carbenium ion formation over $MoO_3$ followed by formation of i-butene. Moreover, it is suggested that H spillover step from Pt surface onto $MoO_3$ is assumed to be the rate determining step and control the overall isomerization rate.

• Proceedings of the Korean Vacuum Society Conference
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• 1993.02a
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• pp.106-107
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• 1993

• Proceedings of the Materials Research Society of Korea Conference
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• 2000.11a
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• pp.65-65
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• 2000