• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.4153-4156
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• 2012

Purpose: To investigate the efficacy and toxicity of a combination of gemcitabine with nedaplatin (GN) or cisplatin (GC) for patients with unresectable or recurrent esophagus squamous cell carcinoma. Methods: Gemcitabine was administered at 1 g/m2 intravenously on days 1 and 8; and nedaplatin or cisplatin were administered at 80 mg/m2 intravenously on day 1. We analyzed the response rate, overall survival time, progression-free survival time, and toxicity in 21 patients treated with GN and 27 patients treated with GC. Results: In patients treated with gemcitabine plus nedaplatin, the ORR was 47.6%, the median progression-free survival time was 4.1 months, and the median survival time was 9.3 months. In patients treated with gemcitabine plus cisplatin, the ORR was 48.2%, the median progression-free survival time was 3.9 months, and the median survival time was 9.1 months, respectively. There were no statistically significant differences in ORR, PFS and OS between the two groups. In both, the most commonly observed toxicities were thrombocytopenia and fatigue. Nausea and vomiting was more frequent in the GC group than in the GN group. Conclusion: Gemcitabine based chemotherapy was effective and tolerable for patients with unresectable or recurrent esophagus squamous cell carcinoma refractory to first line chemotherapy.

• 에너지공학
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• 제23권3호
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• pp.157-162
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• 2014

해당 연구에서는 수정된 폴리올법을 이용하여 합성한 카본블랙 탄소지지체의 Pt촉매의 전기적, 전기화학적 특성을 평가하였다. 또한 Polyol_Pt/C 촉매는 고분자전해질연료전지의 공기극에 적용하여 산소환원반응성을 측정하였다. 산소환원반응성과 고분자전해질연료전지 성능평가를 통해 상용 Pt/C (JM_Pt/C)촉매와 비교하여 전기화학적인 촉매성능을 비교하였다. 촉매의 활성표면적을 구하기 위해 순환전압전류주사법을 이용하였고, 산소환원반응성을 측정하기 위해 회전원판전극으로 선형주사전류법을 이용하였다. 또한 고분자전해질연료전지 완전지 성능 측정을 진행하였다. 그 결과 Polyol_Pt/C 촉매의 활성표면적 ($196m^2g^{-1}$)은 JM_Pt/C 촉매의 그 값 ($183m^2g^{-1}$) 보다 우수하였다. 촉매들의 산소환원반응성에 경우에도 Polyol_Pt/C 촉매는 JM_Pt/C 촉매보다 우수한 반파장전위 및 한계전류밀도를 나타내었다. 또한 완전지 평가시, MEA 공기극을 위한 Polyol_Pt/C 촉매 담지량을 기존의 0.4에서 0.15로 줄였을 때, 성능저하가 적게 나타났고, 300시간의 장기간 성능 평가에서도 연료전지 성능이 거의 일정하게 유지되었다. 이를 토대로 수정된 폴리올법에 의해 합성된 Polyol_Pt/C 촉매는 경제적인 이용 및 우수한 내구성을 가지고 있음을 밝혀내었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.394-394
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• 2016

The oxygen reduction reaction (ORR) in a polymer electrolyte membrane (PEM) fuel cell requires the use of Pt-based catalysts. Due to the high cost and low abundance of Pt, many researchers have been studied to reduce the use of Pt while to enhance the catalytic performance of Pt. One of the promising strategies is the deposition of Pt as ultrathin skins of only a few atomic layers on nanoscale substrates made of another metal. This presentation will discuss the conformal deposition of Pt as uniform, ultrathin shells on Pd nanocrystals. By optimizing the catalytic behavior of Pt-based nanocrystals, we obtained the greatly enhanced ORR activity and durability.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.261-267
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• 2012

Purpose: The relationship between thymidylate synthase (TS) expression and outcomes in gastric cancer (GC) patients remains controversial, although most studies reported poor survival and reduced response to fluoropyrimidine were related to high TS in tumors. We carried out a systematic review of the literature with meta-analysis to estimate the predictive value of TS expression from published studies. Methods: We indentified 24 studies analysing the outcome data in gastric cancer stratified by TS expression. Effect measures of outcome were hazard ratios (HRs) for overall survival (OS) and event-free survival (EFS), or the odds ratio (OR) for overall response rate (ORR). HRs and ORs from these eligible studies were pooled using random-effects meta-analysis. Results: Fifteen studies investigated outcomes in a total of 844 patients with advanced GC, and nine studies investigated outcomes in a total of 1,235 patients with localized GC undergoing adjuvant therapy. Meta-analysis of estimates showed high TS expression was significantly associated with poor OS in the advanced setting (HR: 1.43, 95%CI: 1.08 - 1.90), and poor EFS in the adjuvant setting (HR: 1.53, 95%CI: 1.01 - 2.32). Subgroup analysis demonstrated TS expression to haves even greater value in predicting OS, EFS and ORR in advanced GC patients treated with fluoropyrimidine monotherapy (HR for OS: 2.32, 95%CI: 1.53 - 3.50; HR for EFS: 1.76, 95%CI: 1.19 - 2.60; OR for ORR: 0.32, 95%CI: 0.11 - 0.95). Conclusion: High levels of TS expression were asssociated with a poorer OS for advanced GC patients compared with low levels. In the adjuvant setting, high TS expression was also associated with a worse EFS. Additional studies with consistent methodology are needed to define the precise predictive value of TS.

• Asian Pacific Journal of Cancer Prevention
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• 제16권11호
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• pp.4759-4768
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• 2015

Background: Several studies have investigated predictive and prognostic biomarkers for patients treated with anti-epidermal growth factor receptor (EGFR) agents in lung cancer. However, the conclusion is controversial. Materials and Methods: A meta-analysis was conducted to evaluate the associations of mutant K-ras, PIK3CA and PTEN deficiency with the efficacy of anti-EGFR agents in lung cancer. The primary endpoint was objective response rate (ORR). The secondary endpoints were overall survival (OS) and progression-free survival (PFS). Results: A total of 61 studies were included in the final meta-analysis. The result showed that K-ras mutation was a good predictor for ORR (RR=0.42, 95%CI, 0.33-0.55, p=0.000) and an effective prognostic marker for OS (HR=1.37, 95%CI, 1.15-1.65, p=0.001) and PFS (HR=1.33, 95%CI, 1.05-1.69, p=0.019). However, PTEN deficiency or PIK3CA mutation did not show any significance predictive value for ORR (PTEN, RR=0.82, 95%CI, 0.56-1.19, p=0.286; PIK3CA, RR=1.08, 95%CI, 0.17-6.66, P=0.938). And PTEN deficiency or expression of PIK3CA did not show significance prognostic value for OS (PTEN, HR=0.88, 95%CI, 0.31-2.46,P=0.805; PIK3CA, HR=0.79, 95%CI: 0.23-2.68, P=0.706). Conclusions: Our meta-analysis showed that K-ras mutation may be an effective predictor in lung cancer patients treated with anti-EGFR agents. Whereas, the predictive and prognostic value of PTEN deficiency and PIK3CA mutation need to be further investigated.

• Journal of Electrochemical Science and Technology
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• 제6권4호
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• pp.121-130
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• 2015

The micro emulsion method has been successfully used for preparing perovskite LaCoO₃ with uniform, fine-shaped nanoparticles showing high activity as electro catalysts in oxygen reduction reactions (ORRs). They are, therefore, promising candidates for the air-cathode in metal-air rechargeable batteries. Since the activity of a catalyst is highly dependent on its specific surface area, nanoparticles of the perovskite catalyst are desirable for catalyzing both oxygen reduction and evolution reactions. Herein, LaCoO₃ powder was also prepared by sol-gel method for comparison, with a broad particle distribution and high agglomeration. The electro catalytic properties of LaCoO₃ and LaCoO₃-carbon Super P mixture layers toward the ORR were studied comparatively using the rotating disk electrode technique in 0.1 M KOH electrolyte to elucidate the effect of carbon Super P. Koutecky-Levich theory was applied to acquire the overall electron transfer number (n) during the ORR, calculated to be ~3.74 for the LaCoO₃-Super P mixture, quite close to the theoretical value (4.0), and ~2.7 for carbon-free LaCoO₃. A synergistic effect toward the ORR is observed when carbon is present in the LaCoO₃ layer. Carbon is assumed to be more than an additive, enhancing the electronic conductivity of the oxide catalyst. It is suggested that ORRs, catalyzed by the LaCoO₃-Super P mixture, are dominated by a 2+2-electron transfer pathway to form the final, hydroxyl ion product.

• 전기화학회지
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• 제12권1호
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• pp.11-25
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• 2009

연료전지는 가까운 미래를 위한 핵심 청정 신에너지원 중의 하나로 기대된다. 그러나 고분자 연료전지에서 공기극은 느린 산소환원반응과 많은 백금 사용 때문에 상업화에 어려움을 겪고 있으며, 이것을 해결하는 것이 최근 당면 과제이다. 또한 연료극은 일산화탄소의 피독 현상과 전극의 안정성이 문제시 되고 있다. 본 총설에서는 고분자 연료전지를 위한 연료극, 공기극 전기화학 촉매의 이론적 접근을 통해 촉매를 설계하는 최근 연구 내용을 소개하려 한다. 촉매 설계는 합금 전기 화학 촉매를 통해 접근 했으며, 이는 electronic, geometric, lateral effects를 손쉽게 조절할 수 있게 한다. 이것은 계산되어진 d-band center의 함수에 의존하며, 촉매의 활성과 큰 관계를 가짐을 발견하였다. 본고에서 지향하는 촉매의 최종 방향은 이론적 접근을 통해서 촉매의 사용량을 줄이면서 효율적으로 사용하는 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.731-736
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• 2014

Objective: To observe the short-term efficacy, long-term survival time and adverse responses with nedaplatin (NDP) or cisplatin (DDP) concomitant with other chemotherapy in treating non-small cell lung cancer. Materials and Methods: A retrospective, randomized, control study was conducted, in which 619 NSCLC patients in phases III and IV who were initially treated and re-treated were randomly divided into an NDP group (n=294) and a DDP group (n=325), the latter being regarded as controls. Chemotherapeutic protocols (CP/DP/GP/NP/TP) containing NDP or DDP were given to both groups. Patients in both groups were further divided to evaluate the clinical efficacies according to initial and re-treatment stage, pathological pattern, type of combined chemotherapeutic protocols, tumor stage and surgery. Results: The overall response rate (ORR) and disease control rate (DCR) in the NDP group were 48.6% and 95.2%, significantly higher than in the DDP group at 35.1% and 89.2%, respectively (P<0.01). In NSCLC patients with initial treatment, squamous carcinoma and phase III, there were significant differences in ORR and DCR between the groups (P<0.05), while ORR was significant in patients with adenocarcinoma, GP/TP and in phase IIIa (P<0.05). There was also a significant difference in DCR in patients in phase IIIb (P<0.05). According to the statistical analysis of survival time of all patients and of those in clinical phase III, the NDP group survived significantly longer than the DDP group (P<0.01). The rates of decreased hemoglobin and increased creatinine, nausea and vomiting in the NDP group were evidently lower than in DDP group (P<0.05). Conclusion: NDP concomitant with other chemotherapy is effective for treating NSCLC, with higher clinical efficacy than DDP concomitant with chemotherapy, with advantages in prolonging survival time and reducing toxic and adverse responses.

• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5945-5950
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• 2014

Objectives: To retrospectively review the safety and clinical efficacy of bevacizumab concomitant with chemotherapy in Chinese patients with advanced non-squamous non-small cell lung cancer (NSNSCLC). Methods: Clinical data for 79 patients with NSNSCLC who received bevacizumab concomitant with chemotherapy in Chinese PLA General Hospital from April 28th 2009 to May 5th 2013 were retrospectively reviewed to analyze the clinical efficacy including disease control rate (DCR), overall response rate (ORR), progression-free survival (PFS), overall survival (OS), the Eastern Cooperative Oncology Group (ECOG) score and the safety. Results: The Eastern Cooperative Oncology Group (ECOG) score was 0-2. By the final cutoff date (June 9, 2013), 54 (68.4%) patients had disease progression and 37 (46.8%) died. The ORR was 32.9% and the DCR was 83.5%. The ORR of the first-, second-, and third- or later-line treatments were 51.4%, 25.0% and 12.5%, while the DCR were 94.3%, 80.0% and 70.8%, respectively. The median OS (mOS) and PFS (mPFS) were 13.5 and 5.83 months, respectively. The mOS of patients with the first-, second-, and third- or later- line treatments were 16.2, 10.9 and 8.30 months, while the mPFS were 7.27, 5.90 and 5.17 months, respectively. Chemotherapy-related adverse events included myelosuppression, vomiting, hepatic dysfunction and renal dysfunction, while the common serious bevacizumab-related adverse events were thromboembolic problems, gastrointestinal perforation and reversible posterior leukoencephalopathy syndrome, which could be well managed. Conclusions: Bevacizumab concomitant with chemotherapy is effective and the related toxicity can be well tolerated in Chinese patients with NSNSCLC.

• 한국세라믹학회지
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• 제56권5호
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• pp.497-505
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• 2019

Lanthanum-based transition metal cations containing perovskites have emerged as potential catalysts for the intermediate-temperature (600-800℃) oxygen reduction reaction (ORR). Here, we report a facile acetylacetone-assisted combustion route for the synthesis of nanostructured La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF6428) cathodes for intermediate-temperature solid-oxide fuel cells (IT-SOFCs). The as-prepared powder was analyzed by thermogravimetry analysis-differential scanning calorimetry. The powder calcined at 800℃ was characterized by X-ray diffraction, scanning electrode microscopy, energy dispersive X-ray spectroscopy, and Brunauer-Emmett-Teller surface area measurements. It was found that the porosity of the air electrode significantly increased by utilizing the nanostructured LSCF6428 instead of commercial powder. The performance of a single cell fabricated with the nanostructured LSCF6428 cathode increased by 112%, from 0.4 to 0.85 W cm^-2, at 700℃. Electrochemical impedance spectroscopy showed a considerable reduction in the area-specific resistance and activation energy from 133.5 to 61.5 kJ/mol, resulting in enhanced electrocatalytic activity toward ORR and overall cell performance.