• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.1
• /
• pp.205-216
• /
• 2015

Background: Many developing countries are lagging behind in reporting epidemiological data for individual central nervous system (CNS) tumors. This paper aimed to elicit patterns for the epidemiology of individual World Health Organization (WHO) classified CNS tumors in countries registered by WHO as "developing". Materials and Methods: Cyber search was carried out through 66 cancer networks/registries and 181 PubMed published papers that reported counts of CNS tumors for the period of 2009-2012. The relationship between the natural log of incidence Age Standardized Rate (ASR) reported by Globocan and Latitude/ Longitude was investigated. Results: Registries for 21 countries displayed information related to CNS tumors. In contrast tends for classified CNS tumor cases were identified for 38 countries via 181 PubMed publications. Extracted data showed a majority of unclassified reported cases [PubMed (38 countries, 45.7%), registries (21 countries, 96.1%)]. For classified tumors, astrocytic tumors were the most frequently reported type [PubMed (38 countries, 1,245 cases, 15.7%), registries (21 countries, 627 cases, 1.99%]. A significant linear regression relationship emerged between latitudes and reported cases of CNS tumors. Conclusions: Previously unreported trends of frequencies for individually classified CNS tumors were elucidated and a possible link of CNS tumors occurrence with geographical location emerged.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.5
• /
• pp.2179-2183
• /
• 2014

Background: In vitro, in vivo and clinical studies have demonstrated anti-cancer effects of deuterium depleted water (DDW). The nature of this agents action, cytotoxic or cytostatic, remains to be elucidated. We here aimed to address the point by examining effects on different cell lines. Materials and Methods: 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) -based cytotoxicity analysis was conducted for human breast, stomach, colon, prostate cancer and glioblastoma multiforme cell lines as well as human dermal fibroblasts. The cell lines were treated with decreasing deuterium concentrations of DDW alone, paclitaxel alone and both. One way analysis of variance (ANOVA) was used for statistical analysis. Results: Treatment with different deuterium concentrations of DDW alone did not impose any significant inhibitory effects on growth of cell lines. Paclitaxel significantly decreased the survival fractions of all cell lines. DDW augmented paclitaxel inhibitory effects on breast, prostate, stomach cancer and glioblastoma cell lines, with influence being more pronounced in breast and prostate cases. Conclusions: DDW per se does not appear to have inhibitory effects on the assessed tumor cell lines as well as normal fibroblasts. As an adjuvant, however, DDW augmented inhibitory effects of paclitaxel and thus it could be considered as an adjuvant to conventional anticancer agents in future trials.

• Journal of Preventive Medicine and Public Health
• /
• v.42 no.2
• /
• pp.130-134
• /
• 2009

Objectives : A method of estimation using 8 populationbased cancer registries databases in Korea(KRCR DB) has been introduced as another strategy for validly estimating the national cancer incidence(NCI) in Korea. The purpose of this study was to evaluate the validity of this method with using the 7 KRCR DBs, excluding Seoul covering 21% of the total population of Korea. Methods : We designed the study method(NCSE_7) as same as the estimating method with using 8 KRCR DBs (NCSE_8) in order to ensure maximal comparability. We defined the expected number of cancer cases in each registry as the number of observed cases and then we added the weighted observed cases according to gender, age and the proportion of the population covered by each registry for the population of the seven regions and the population of all areas, with excluding these seven regions. From the expected number of total cancer incidents, the estimated NCI was calculated by dividing the expected number of cancer cases by the number of the total population. The standard error(SE) of the estimated incidence was also taken from the expected number of total cancer incidents. Results : Compared with the results of the NCSE_8, the overall age-standardized rates(ASR) in men and women became over-estimated and under-estimated, respectively. Primary sites that showed statistically significant differences were the colo-rectum, prostate, breast and thyroid. The index of death certificate only(DCO)and microscopically verified(MV)% indicating levels of data quality were decreased, especially for the brain in DCO% and kidney in the MV%. Conclusions : The database of Seoul regional cancer registry has a key role for the method to estimate the valid nationwide cancer statistics in Korea with using the population-based cancer registries databases.

• Journal of Preventive Medicine and Public Health
• /
• v.41 no.6
• /
• pp.380-386
• /
• 2008

Objectives: Valid data on the national cancer incidence (NCI) is the data should be needed to plan, monitor and evaluate the national cancer control programs. The purpose of this study was to estimate the NCI for 2000-2002 from 8 population-based cancer registries database in Korea (KRCR DB). Methods: We defined the expected number of cancer cases in each registry as the number of observed cases and then adding to the weighted observed cases, according to sex, age groups, and the proportion of the population covered by each registry for the population of the eight regions and the population of all areas with excluding the 8 regions. From the expected number of total cancer incidents, he estimated NCI was calculated by dividing the expected number of cancer cases by he umber of the total population. The standard error (SE) of the estimated incidence was also taken from the expected number of total cancer incidents. Results: The overall estimated crude rates in 2000-2002 ere 267.1 and 219.0 per 100,000 for men and women, respectively. The overall age-standardized rates (ASR) were 290.1 and 180.7 per 100,000, respectively. Compared with the ASRs obtained from Korea National Cancer Incidence database (KNCI DB), the estimated ASRs from the KRCR DB did not show statistically significant differences except for some cancers in women. For the aspect of the SE, index of DCO(death certificate only) and of MV(microscopically verified), the estimated ASRs from the KRCR DB are more accurate and they have higher quality rather than the calculated ASRs from the KNCI DB. Conclusions: We found that this developed method using the KRCR DB is valid and it could be another strategy for estimating the NCI in Korea.

• Journal of the Korean Ceramic Society
• /
• v.56 no.5
• /
• pp.497-505
• /
• 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.

• Clean Technology
• /
• v.18 no.4
• /
• pp.373-378
• /
• 2012

The end-of-life vehicles (ELV) are important recycling sources, and there are several stages involved in the recycling such as dismantling, shredding, and treatment of shredder residues (ASR). The legal recycling rate should be at least 95% on and after 2015, while we need a proper system to monitor recycling of ELV components and to calculate the practical recycling rate. The paper suggests a monitoring system that calculates practical recycling rates of dismantled components by use of a database of standard recycling rate as well as a web-based monitoring, which is linked to the Eco Assurance system for electric & electronic equipment and vehicle (EcoAS). Also the system supports dismantling and monitoring process by incorporating a standard vehicular component database, which facilitates recording dismantled weight data but also monitoring of dismantled components.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.1
• /
• pp.50-55
• /
• 2001

This paper presents a korean isolated words recognition algorithm which used new endpoint detection method, auditory model, 2D-DCT and new distance measure. Advantages of the proposed algorithm are simple hardware construction and fast recognition time than conventional algorithms. For comparison with conventional algorithm, we used DTW method. At result, we got similar recognition rate for speaker dependent korean isolated words and better it for speaker independent korean isolated words. And recognition time of proposed algorithm was 200 times faster than DTW algorithm. Proposed algorithm had a good result in noise environments too.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2009.05a
• /
• pp.56.1-56.1
• /
• 2009

The intermediate operating temperature of solid oxide fuel cells (IT-SOFCs) have achieved considerable importance in the area of power fabrication. This is because to improve materials compatibility, their long-term stability and cost saving potential. However, to conserve rational cell performance at reduced-temperature regime, cathode performance should be obtained without negotiating the internal resistance and the electrode kinetics of the cell. Recently, double perovskite structure cathodes have been studied with great attention as a potential material for IT-SOFCs. In this study, double-perovskite structured cathodes of $GdBaCoCuO_{5+\delta}$, $GdBaCo_{2/3}Cu_{2/3}Fe_{2/3}O_{5+\delta}$ compositions and $(1-x)GdBaCo_2O_{5+\delta}+xCe_{0.9}Gd_{0.1}O_{1.95}$ (x = 10, 20, 30 and 40 wt.%) composites were evaluated as the cathode for intermediate temperature solid oxide fuel cells(IT-SOFCs). Electrical conductivity of the cathodes were measured by DC 4-probe method, and the thermal expansion coefficient of each sample was measured up to $900^{\circ}C$ by a dilatometer study. Area specific resistances(ASR) of the $GdBaCo_{2/3}Cu_{2/3}Fe_{2/3}O_{5+\delta}$ cathode and 70 wt.% $GdBaCo_2O5+\delta$ + 30wt.% Ce0.9Gd0.1O1.95 composite cathode on CGO electrolyte substrate were analyzed using AC 3-probe impedance study. The obtained results demonstrate that double perovskite-based compositions are promising cathode materials for IT-SOFCs.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.5
• /
• pp.825-830
• /
• 2001

Escherichia coli, which harbored the ars operon from a plasmid pMH12 of Klebsiella oxytoca D12, showed filamentation due to the expression of ars genes in the presence of arsenite. The continued DNA replication in the absence of cell division was revealed, since nucleoids abound with DAPI appeared to be arranged in chains. In contrast to overexpression of arsA, its frame-shift mutant and knock-out mutant lost filamentation in the presence of arsenite, which suggested that ars-induced division block was dependent on expression of arsA. ArsA-induced division inhibition was not a consequence of an inhibition of DNA replication, and the inability of arsenite to induce an SOS response indicated that arsA-mediated division inhibition was dependent on the expression of the gene product encoded by the minB operon. ArsA is a peripheral membrane protein with an ATP-binding domain, which is homologous to MinD that requires ATP-dependent efflux. These results suggested that ArsA could possibly recruit MinC to the membrane and modulate cytoplasmic FtsZ to block assembly at the middle of the cell.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2000.02a
• /
• pp.69-69
• /
• 2000

(Ba, Sr)TiO3 (BST)[1-3] 박막은 유전상수가 크고 고주파에서도 유전특성 저하가 적기 때문에 ULSI DRAM(Dynamic Random Access Memory)에 응용 가능한 물질로 최근 각광을 받고 있다. 하지만, 아직 BST 박막을 DRSM에 바로 적용하기 위해선 몇 가지 문제점이 있다. 그 중 누설전류 문제는 디바이스 응용시 매우 중요한 요소이다. 특히, DRAM에서 refresh time와 직접적인 관련이 있어 디바이스 내의 신뢰도 및 전력소모를 결정하는 주된 인자가 된다. 지금까지, BST 박막의 인가전업, 온도, 그리고 전극물질에 따른 누설전류 현상들이 고찰되었고, 이에 관한 많은 전도기구 모델들이 제시되었다. Schottky emission, Poole-Frenkel emission, space charge limited conduction 등이 그 대표적인 예이다. 하지만 아쉽게도 BST 박막의 정확한 누설 전류 전도 기구를 완전히 설명하는데는 아직 한계가 있다. 따라서 본 연구에서는 제작된 BST 커패시터 내의 기본적인 전기적 성질을 조사하고, 정확한 누설전류 기구 규명에 초점을 두고자 한다. 이를 위해 기존의 여러 기구들과 비교 분석할 것이다. 하부전극으로 사용하기 위해 스퍼터링 방법으로 p-Si(100) 기판위에 RuO2 박막을 약 120nm 증착하였다. 증착전의 chamberso의 초기압력은 5$\times$10-6 Torr이하의 압력으로 유지시켰다. Ar/O2의 비는 이전 실험에서 최적화된 9/1로 하였다. BST 박막 증착 시 5분간 pre-sputtering을 실시한 후 하부전극 기판위에 BST 박막을 증착하였다. 증착이 끝난 후 시편을 상온까지 냉각시킨 후 꺼내었다. 전기적 특성을 측정하기 상부전극으로 RuO2와 Al 박막을 각각 상온에서 100nm 증착하였다. 이때 hole mask를 이용하여 반경이 140um인 원형의 상부전극을 증착하였다. BST 박막의 증착온도가 증가하고 Ar/O2 비가 감소할수록 제작된 BST-커패시터의 전기적 성질이 우수하였다. 증착온도 $600^{\circ}C$, ASr/O2=5/5에서 증착된 막의 누설전류는 4.56$\times$10-8 A/cm2, 유전상수는 600 정도의 값을 나타내었다. 인가전압에 따른 BST 커패시터의 transition-current는 Curie-von Schweider 모델을 따랐다. BST 박막의 누설전류 전도기구는 기존의 Schottky 모델이 아니라 modified-Schottky 무델로 잘 설명되었다. Modified-Schottky 모델을 통해 BST 박막의 광학적 유전율 $\varepsilon$$\infty$=4.9, 이동도 $\mu$=0.019 cm2/V-s, 장벽 높이 $\psi$b=0.79 eV를 구하였다.