• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10837-10840
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• 2015

To assess survival outcomes in a retrospective study, recurrent epithelial ovarian cancer patients were divided into three groups according to the platinum free interval as follows: platinum refractory that included the patients with tumor progression during treatment; platinum resistant and platinum sensitive that included the patients with tumor progression less than or more than six months, respectively. Clinical data for tumor progression in epithelial ovarian cancer patients treated at Chiang Mai University Hospital between January, 2006 and December, 2010 were reviewed. Thirty-nine patients were in the platinum refractory group while 27 were in the platinum resistant group and 75 in the platinum sensitive group. The mean age, the parity, the administration of neoadjuvant chemotherapy and the serous type did not significantly different across groups while the mean total number of chemotherapy regimens, the early stage patients, the patients with complete surgery and the surviving patients were significant more frequent in the platinum sensitive group. Regarding subsequent treatment after tumor recurrence, 87.2% underwent chemotherapy. With the median follow up time at 29 months, the median overall survival rates were 20 months, 14 months and 42 months in platinum refractory, platinum resistant and platinum sensitive groups, respectively (p<0.001). In addition, when the platinum sensitive patients developed the next episode of tumor progression, the median progression free interval time was only three to four months. In conclusion, the outcomes for platinum refractory the and platinum resistant groups was poorer than the platinum sensitive group. However, subsequent progression in the platinum sensitive group was also associated with a poor outcome.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.476-481
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• 1999

Characteristics of platinum dry etching were investigated in a cryogenic magnetized inductively coupled plasma (MICP). The problem with platinum etching is the redeposition of sputtered platinum on the sidewall. Because of the redeposits on the sidewall, the etching of patterned platinum structure produces feature sizes that exceed the original dimension of the PR size and the etch profile has needle-like shape [1]. The main object of this study was to investigate a new process technology for fence-free Pt etching As bias voltage increased, the height of fence was reduced. In cryogenic etching, the height of fence was reduced to 20% at-$190^{\circ}C$ compared with that of room temperature, however the etch profile was not still fence-free. In Ar/$SF_6$ Plasma, fence-free Pt etching was possible. As the ratio of $SF_6$ gas flow is more than 14% of total gas flow, the etch profile had no fence. Chemical reaction seemed to take place in the etch process.

• Korean Journal of Materials Research
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• v.25 no.4
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• pp.191-195
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• 2015

To improve its textural properties as a support for platinum catalyst, carbon aerogel was chemically activated with KOH as a chemical agent. Carbon-supported platinum catalyst was subsequently prepared using the prepared carbon supports(carbon aerogel(CA), activated carbon aerogel(ACA), and commercial activated carbon(AC)) by an incipient wetness impregnation. The prepared carbon-supported platinum catalysts were applied to decalin dehydrogenation for hydrogen production. Both initial hydrogen evolution rate and total hydrogen evolution amount were increased in the order of Pt/CA < Pt/AC < Pt/ACA. This means that the chemical activation process served to improve the catalytic activity of carbon-supported platinum catalyst in this reaction. The high surface area and the well-developed mesoporous structure of activated carbon aerogel obtained from the activation process facilitated the high dispersion of platinum in the Pt/ACA catalyst. Therefore, it is concluded that the enhanced catalytic activity of Pt/ACA catalyst in decalin dehydrogenation was due to the high platinum surface area that originated from the high dispersion of platinum.

• Tuberculosis and Respiratory Diseases
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• v.81 no.2
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• pp.148-155
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• 2018

Background: Although targeted therapy and immuno-oncology have shifted the treatment paradigm for lung cancer, platinum-based combination is still the standard of care for advanced non-small cell lung cancer (NSCLC). Pemetrexed continuation maintenance therapy has been approved and increasingly used for patients with nonsquamous NSCLC. However, the efficacy of this strategy has not been proven in patients without driving mutations. The objective of this study was to compare the clinical benefit of pemetrexed continuation maintenance to conventional platinum-based doublet in epidermal growth factor receptor (EGFR)-negative lung adenocarcinoma. Methods: A total of 114 patients with EGFR-negative lung adenocarcinoma who were treated with platinum doublet were retrospectively enrolled. We compared the survival rates between patients received pemetrexed maintenance after four-cycled pemetrexed/cisplatin and those received at least four-cycled platinum doublet without maintenance chemotherapy as a first-line treatment. Results: Forty-one patients received pemetrexed maintenance and 73 received conventional platinum doublet. Median progression-free survival (PFS), which was defined as the time from the day of response evaluation after four cycles of chemotherapy to disease progression or death, was significantly higher in the pemetrexed maintenance group compared to conventional group (5.8 months vs. 2.2 months, p<0.001). Median overall survival showed an increasing trend in the pemetrexed maintenance group (22.3 months vs. 16.1 months, p=0.098). Multivariate analyses showed that pemetrexed maintenance chemotherapy was associated with better PFS (hazard ratio, 0.73; 95% confidence interval, 0.15-0.87). Conclusion: Compared to conventional platinum-based chemotherapy, premetrexed continuation maintenance treatment is associated with better clinical outcome for the patients with EGFR wild-type lung adenocarcinoma.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1145-1148
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• 2014

Background: Single pegylated liposomal doxorubicin (PLD) is commonly used as a salvage treatment in platinum-resistant ovarian cancer, fallopian tube cancer and primary peritoneal adenocarcinoma (PPA) with a satisfactory outcome. However, the data for second generation PLD administered in this setting are still limited. We conducted a retrospective study to evaluate the outcome of patients who received single-agent second generation PLD (LIPO-DOX) after the development of clinical platinum resistance. The study period was between March 2008 and March 2013. LIPO-DOX was administered intravenously 40 $mg/m^2$ every 28 days until disease progression, but for not more than six cycles. The response rate was evaluated using the Gynecologic Cancer Intergroup (GCIG) criteria while the toxicity was evaluated according to WHO criteria. Twenty-nine patients met the inclusion criteria in the study period with an overall response rate of 13.8%. The median progression free survival and overall survival were three and eleven months, respectively. With the total of 96 cycles of chemotherapy, the patients developed grades 3 and 4 hematologic toxicity as follows: anemia, 0%, leukopenia, 9.6%, neutropenia, 32.3% and thrombocytopenia, 0%. In conclusion, the single agent second generation PLD demonstrated modest efficacy in patients with platinum-resistant ovarian cancer, fallopian tube cancer and PPA without serious toxicity.

• Archives of Plastic Surgery
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• v.45 no.3
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• pp.222-228
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• 2018

Background The most common surgical treatment for paralytic lagophthalmos is the placement of a weight implant in the upper eyelid; however, this technique confers the risks of implant visibility, implant extrusion, and entropion. In this study, we present a new technique of placing platinum weight implants between the levator aponeurosis and inner septum to decrease such complications. Methods A total of 37 patients with paralytic lagophthalmos were treated between March 2014 and January 2017 with platinum weight placement (mean follow-up, 520.1 days). After dissecting through the orbicularis oculi muscle, the tarsal plate and levator aponeurosis were exposed. The platinum weights (1.0-1.4 g) were fixed to the upper margin of the tarsal plate and placed underneath the orbital septum. Results Five patients could partially close their eye after surgery. The average distance between the upper eyelid and the lower eyelid when the eyes were closed was 1.12 mm. The rest of the patients were able to close their eye completely. Three patients patient developed allergic conjunctivitis after platinum weight insertion, which was managed with medication. None of the patients complained of discomfort in the upper eyelid after surgery. Visibility or extrusion of the implant were observed in three patients. Conclusions Postseptal weight placement is a safe and reproducible method in both primary and secondary upper eyelid surgery for patients with paralytic lagophthalmos. It is a feasible method for preventing implant visibility, implant exposure, and entropion. Moreover, platinum is a better implant material than gold because of its smaller size and greater thinness.

• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.30-38
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• 2021

Objective : The Solitaire Platinum 4×40 mm stent retriever contains radiopaque markers with a long length. We evaluated the effect of Solitaire Platinum 4×40 mm stent retriever in Solumbra technique thrombectomy, and compared it with shorter Solitaire stent retrievers. Methods : A total of 70 patients who underwent Solumbra technique thrombectomy with equal diameter (4 mm) and different length (40 vs. 20 mm) Solitaire stent retrievers were divided into two groups : the Solitaire Platinum 4×40 mm stent (4×40) group and the Solitaire FR 4×20 mm stent or Solitaire Platinum 4×20 mm stent (4×20) group. The clinical outcomes, Thrombolysis in Cerebral Infarction score, the first pass reperfusion status, and complications were evaluated and compared between the two groups. Multivariate analysis was performed to evaluate the predictive factors for reperfusion and complete reperfusion from the first pass. Results : Higher first-pass reperfusion and complete reperfusion were achieved in the 4×40 group (68.0% and 48.0%) than in the 4×20 group (46.7% and 33.3%; p=0.004 and 0.007, respectively). In multivariate analysis, radiopaque device and longer stent retriever were correlated with first-pass reperfusion (p=0.014 and 0.008, respectively) and first-pass complete reperfusion (p=0.022 and 0.012, respectively). Conclusion : Our study demonstrated the usefulness of the Solitaire Platinum 4×40 mm stent retriever, which led to higher first-pass reperfusion and complete reperfusion rates than the Solitaire FR 4×20 mm stent or the Solitaire Platinum 4×20 mm stent, especially in Solumbra technique thrombectomy.

• Journal of the Korean Society of Combustion
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• v.5 no.1
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• pp.1-6
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• 2000

Surface reaction occurs at a certain surface temperature when a catalyst is heated up in a reactive mixture. If homogeneous ignition does not occur, a steady state is observed because the heat produced by the surface reaction is balanced with the heat loss caused by convection, conduction and radiation. The present paper treats the effects of pressure on the surface temperature at the steady state. Hydrogen and oxygen are used as reactants and nitrogen as an inert gas. A spherical platinum catalyst of 1.5 mm in diameter is sustained in the chamber with two wires of 0.1 mm in diameter. As results, there exists a maximum steady temperature at a certain relative hydrogen concentration which increases with total pressure. At the steady state, it can be approximated that the heat release is estimated by the mass transfer considering the effect of natural convection. The experimental results are explained qualitatively by the approximation.

• Journal of the Korean Society of Mineral and Energy Resources Engineers
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• v.56 no.4
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• pp.359-366
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• 2019

This article aims to summarize the recycling status of scrap gold, silver, platinum, and palladium by regions and industries in order to utilize the data for securing raw materials of the domestic urban mining industry. The amount of gold from scrap has shown a tendency to decrease in countries other than China over the last ten years, which is attributed to the increase in scrap containing gold in China. The industry demand for gold is the highest in electronic products, but it is decreasing. The amount of scrap recycling for silver has declined but total silver production has increased by increasing mine products. As production and demand from platinum and palladium scrap are mostly for catalysts, their demand could be affected by the electric vehicle industry.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.799-805
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• 2016

Background: There is no standard treatment for patients with platinum-resistant or refractory epithelial ovarian cancer. Single agent chemotherapies have evidence of more efficacy and less toxicity than combination therapy. Most are very expensive, with appreciable toxicity and minimal survival. Since it is difficult to make comparison between outcomes, economic analysis of single-agent chemotherapy regimens and best supportive care may help to make decisions about an appropriate management for the affected patients. Objective: To evaluate the cost effectiveness of second-line chemotherapy compared with best supportive care for patients with platinum-resistant or refractory epithelial ovarian cancer. Materials and Methods: A Markov model was used to estimate the effectiveness and total costs associated with treatments. The hypothetical patient population comprised women aged 55 with platinum-resistant or refractory epithelial ovarian cancer. Four types of alternative treatment options were evaluated: 1) gemcitabine followed by BSC; 2) pegylated liposomal doxorubicin (PLD) followed by BSC; 3) gemcitabine followed by topotecan; and 4) PLD followed by topotecan. Baseline comparator of alternative treatments was BSC. Time horizon of the analysis was 2 years. Health care provider perspective and 3% discount rate were used to determine the costs of medical treatment in this study. Quality-adjusted life-years (QALY) were used to measure the treatment effectiveness. Treatment effectiveness data were derived from the literature. Costs were calculated from unit cost treatment of epithelial ovarian cancer patients at various stages of disease in King Chulalongkorn Memorial Hospital (KCMH) in the year 2011. Parameter uncertainty was tested in probabilistic sensitivity analysis by using Monte Carlo simulation. One-way sensitivity analysis was used to explore each variable's impact on the uncertainty of the results. Results: Approximated life expectancy of best supportive care was 0.182 years and its total cost was 26,862 Baht. All four alternative treatments increased life expectancy. Life expectancy of gemcitabine followed by BSC, PLD followed by BSC, gemcitabine followed by topotecan and PLD followed by topotecan was 0.510, 0.513, 0.566, and 0.570 years, respectively. The total cost of gemcitabine followed by BSC, PLD followed by BSC, gemcitabine followed by topotecan and PLD followed by topotecan was 113,000, 124,302, 139,788 and 151,135 Baht, respectively. PLD followed by topotecan had the highest expected quality-adjusted life-years but was the most expensive of all the above strategies. The incremental cost-effectiveness ratios (ICER) of gemcitabine followed by BSC, PLD followed by BSC, gemcitabine followed by topotecan and PLD followed by topotecan was 344,643, 385,322, 385,856, and 420,299 Baht, respectively. Conclusions: All of the second-line chemotherapy strategies showed certain benefits due to an increased life-year gained compared with best supportive care. Moreover, gemcitabine as second-line chemotherapy followed by best supportive care in progressive disease case was likely to be more effective strategy with less cost from health care provider perspective. Gemcitabine was the most cost-effective treatment among all four alternative treatments. ICER is only an economic factor. Treatment decisions should be based on the patient benefit.