• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8093-8100
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• 2016

Background: Genetic and environmental factors play important roles in pathogenesis of digestive tract cancers like those in the esophagus, stomach and colorectum. Folate deficiency and methylenetetrahydrofolate reductase (MTHFR) as an important enzyme of folate and methionine metabolism are considered crucial for DNA synthesis and methylation. MTHFR variants may cause genomic hypomethylation, which may lead to the development of cancer, and MTHFR gene polymorphisms (especially C677T and A1298C) are known to influence predispositions for cancer development. Several case control association studies of MTHFR C677T polymorphisms and colorectal cancer (CRC) have been reported in different populations with contrasting results, possibly reflecting inadequate statistical power. Aim: The present meta-analysis was conducted to investigate the association between the C677T polymorphism and the risk of colorectal cancer. Materials and Methods: A literature search of the PubMed, Google Scholar, Springer link and Elsevier databases was carried out for potential relevant articles. Pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was calculated to assess the association of MTHFR C677T with the susceptibility to CRC. Cochran's Q statistic and the inconsistency index (I2) were used to check study heterogeneity. Egger's test and funnel plots were applied to assess publication bias. All statistical analyses were conducted by with MetaAnalyst and MIX version 1.7. Results: Thirty four case-control studies involving a total of 9,143 cases and 11,357 controls were retrieved according to the inclusion criteria. Overall, no significant association was found between the MTHFR C677T polymorphism and colorectal cancer in Asian populations (for T vs. C: OR=1.03; 95% CI= 0.92-1.5; p= 0.64; for TT vs CC: OR=0.88; 95%CI= 0.74-1.04; p= 0.04; for CT vs. CC: OR = 1.02; 95%CI= 0.93-1.12; p=0.59; for TT+ CT vs. CC: OR=1.07; 95%CI= 0.94-1.22; p=0.87). Conclusions: Evidence from the current meta-analysis indicated that the C677T polymorphism is not associated with CRC risk in Asian populations. Further investigations are needed to offer better insight into any role of this polymorphism in colorectal carcinogenesis.

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.213.4-213
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• 2003

No Abstract, See Full Text

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1298-1305
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• 2018

The use of System-on-Chip (SoC) solutions in the design of on-board data handling systems is an important step towards further miniaturization in space. However, the Total Ionizing Dose (TID) and Single Event Effects (SEE) characterization of these complex devices present new challenges that are either not fully addressed by current testing guidelines or may result in expensive, cumbersome test configurations. In this paper we report the test setups, procedures and results for TID testing of a SoC microcontroller both using standard $^{60}Co$ and low-energy protons beams. This paper specifically points out the differences in the test methodology and in the challenges between TID testing with proton beam and with the conventional gamma ray irradiation. New test setup and procedures are proposed which are capable of emulating typical mission conditions (clock, bias, software, reprogramming, etc.) while keeping the test setup as simple as possible at the same time.

• Journal of Life Science
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• v.25 no.11
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• pp.1298-1303
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• 2015

Machilus thunbergii (Lauraceae) is an evergreen tree cultivated in Korea and Japan. M. thunbergii has long been used as a traditional medicine in Korea, China, and Japan to treat various diseases, including edema, abdominal pain, and abdominal distension. In this study, dried stem bark of M. thunbergii extracted in methanol and extract was partitioned into n-hexane, CHCl₃, and BuOH. The CHCl₃-soluble extracts chromatographed on silica gel column using a CHCl₃/acetone and n-hexane/EtOAc mixture to afford Compound 1 and 2. Two dibenzylbutane lignans, macelignan (1) and meso-dihydroguaiaretic acid (2), were isolated from the CHCl₃-soluble extract of M. thunbergii stem bark. The structures of 1 and 2 were determined by ¹H- and ¹³C-NMR spectroscopic data analyses and a comparison with literature data. The tyrosinase inhibitory activity of the isolated compounds was evaluated. Among these compounds, Compound 2 strongly inhibited the monophenolase (IC₅₀=10.2 μM) activity of tyrosinase. A kinetic analysis showed that Compound 2 was a competitive inhibitor. The apparent inhibition constant (K_i) for Compound 2 binding to free enzyme was 4.8 μM. Based on these results, it can be concluded that meso-dihydroguaiaretic acid (2) is a potential candidate for the treatment of melanin biosynthesis-related skin diseases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1298-1306
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• 2014

In this paper, we use the ECMA-392 standard, the first cognitive radio networks to meet the demand for IT services in the ship. And, we investigate about the conflicts of devices that support multi-hop network based on the ECMA-392. Therefore, we propose the resolution scheme of CRP reservation conflicts to solve this. The current CRP reservation approaches does not solve the CRP reservation conflicts of ECMA-392 between devices that move at a distance of three hops. Therefore, it is not possible to guarantee the QoS of real time services such as multimedia streaming. So, we provide a new CRP reservation scheme to avoid conflict through a new 2-hop CRP Availability IE and the change of CRP Control field. From the simulation results, we know that the proposed method of 3 hops CRP reservation conflicts resolution improves the throughput of device.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1298-1303
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• 2004

The characteristics of soot near the soot inception point for an ethene-air flame was carried out in a WSR (well-stirred reactor). The new sampling tool like the temperature controlled filter system was introduced to minimize the condensation during sampling. The new analysis tools applied include the real time size distribution analysis with the Nano-DMA, particle size by transmission electron microscopy, C/H analysis, g filter analysis, and thermogravimetric analysis using both non-oxidative and oxidative pyrolysis. The WSR can generate young soot particles that can be collected and examined to gain insight into inception. For the current conditions, soot does not form for ${\Phi}=1.9$, inception occurs at or before ${\Phi}=2.0$, and inception combined with soot surface growth and/or coagulation occurs for ${\Phi=2.1}$. The filter samples for ${\Phi}$=1.9 are composed of volatile compounds that evolve at relatively low temperatures when heated in the presence or absence of $O_2$. The samples collected from the WSR at ${\Phi}=2.0$ and ${\Phi}=2.1$ are precursor-like in morphology and size. They have higher C/H ratios and lower organic percentages than precursor particles, but they are clearly not fully carbonized soot. The WSR PAH distribution is similar to that in young soot from inverse flames.

• Journal of the Korean Institute of Gas
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• v.5 no.1
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• pp.60-72
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• 2001

This paper presents the user-interactive productivity analysis model based on material balance as well as deliverability equations equipped with EOS model to perform a productivity analysis for Gorae V structure, Donghae-1 gas field. This model is designed to be able to analyse the productivity in the case of reservoir contacting with the aquifer. Also, in order to investigate the effect of condensation on productions, condensation phenomenon is considered as an apparent skin effect in the computation of bottomhole pressure from average reservoir pressure. By utilizing the developed model, we investigate the productivity analysis for B2 layer of Garae V structure with the various production cases in volumetric and non­volumetric reservoirs that contact with aquifer. From the results in the case of 5500 MMSCF/year of production and reservoir-aquifer contacting angle 270$^{\circ}C$ with aquifer size of 10 times greater than reservoir, B2 layer could maintain peak production rate even after 8.5 years of production by considering the bottomhole pressure which is estimated above the operating pressure of 1298 psia. It is also found that condensate will be formed after 1100 days of production and existed throughout the reservoir at 1270 days. Note that the computed reservoir pressure of B2 layer is maintained sufficiently high enough for production due to the water influx into the reservoir, and skin effect caused by condensation is not significant.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1292-1298
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• 2022

Soil autotrophic bacterial communities play a significant role in the soil carbon (C) cycle in paddy fields, but little is known about how rhizosphere soil microorganisms respond to different long-term (35 years) fertilization practices under double rice cropping ecosystems in southern China. Here, we investigated the variation characteristics of rhizosphere soil RubisCO gene cbbL in the double rice ecosystems of in southern China where such fertilization practices are used. For this experiment we set up the following fertilizer regime: without any fertilizer input as a control (CK), inorganic fertilizer (MF), straw returning (RF), and organic and inorganic fertilizer (OM). We found that abundances of cbbL, 16S rRNA genes and RubisCO activity in rhizosphere soil with OM, RF and MF treatments were significantly higher than that of CK treatment. The abundances of cbbL and 16S rRNA genes in rhizosphere soil with OM treatment were 5.46 and 3.64 times higher than that of CK treatment, respectively. Rhizosphere soil RubisCO activity with OM and RF treatments increased by 50.56 and 45.22%, compared to CK treatment. Shannon and Chao1 indices for rhizosphere soil cbbL libraries with RF and OM treatments increased by 44.28, 28.56, 29.60, and 23.13% compared to CK treatment. Rhizosphere soil cbbL sequences with MF, RF and OM treatments mainly belonged to Variovorax paradoxus, uncultured proteobacterium, Ralstonia pickettii, Thermononospora curvata, and Azoarcus sp.KH33C. Meanwhile, cbbL-carrying bacterial composition was obviously influenced by soil bulk density, rhizosphere soil dissolved organic C, soil organic C, and microbial biomass C contents. Fertilizer practices were the principal factor influencing rhizosphere soil cbbL-carrying bacterial communities. These results showed that rhizosphere soil autotrophic bacterial communities were significantly changed under conditions of different long-term fertilization practices Therefore, increasing rhizosphere soil autotrophic bacteria community with crop residue and organic manure practices was found to be beneficial for management of double rice ecosystems in southern China.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1291-1298
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• 2015

Five different polymer nanofibers, namely, polyaniline nanofiber (PANI), magnetically separable polyaniline nanofiber (PAMP), magnetically separable DEAE cellulose fiber (DEAE), magnetically separable CM cellulose fiber (CM), and polystyrene nanofiber (PSNF), have been used for the immobilization of lactase (E.C. 3.2.1.23). Except for CM and PSNF, three polymers showed great properties. The catalytic activities (k_cat) of the free, PANI, PAMP, and magnetic DEAE-cellulose were determined to be 4.0, 2.05, 0.59, and 0.042 mM/min·mg protein, respectively. The lactase immobilized on DEAE, PANI, and PAMP showed improved stability and recyclability. PANI- and PAMP-lactase showed only a 0-3% decrease in activity after 3 months of vigorous shaking conditions (200 rpm) and at room temperature (25℃). PANI-, PAMP-, and DEAE-lactase showed a high percentage of conversion (100%, 47%, and 12%) after a 1 h lactose hydrolysis reaction. The residual activities of PANI-, PAMP-, and DEAE-lactase after 10 times of recycling were 98%, 96%, and 97%, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9C
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• pp.1298-1305
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• 2004

Most watermarking techniques embed watermarks in the middle frequency range for robustness and invisibility. In our proposed watermarking algorithms embed the gaussian sequence watermark into low frequency area of the wavelet transform domain because the histogram of low sub-band area is composed by similar coefficients. Also, our proposed scheme doesn't need the original image in extraction procedure The experimental results show good robustness against the Check Mark benchmarking tools.