Broadband Reflection of Polarization Conversion by 90 in Metamaterial

P. V. Tuong,J. W. Park,Y. J. KIM,Y. J. Yoo,Y. P. Lee,J. Y. Rhee,K. W. Kim,S. A. Nikitov,N. H. T. Anh 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.8

We developed a reflection polarization convertor by using the conventional metamaterial absorber. The metal-dielectric-metal sandwich structure, in which copper split ring at the front and metallicplane at the back are separated by FR-4, was employed to investigate for the GHz regime. Thisshows that a broadband of 14−18 GHz with reflectance of 36−55% is converted to 90 -polarizationmode, while the original one is nearly harvested (absorption of 95−100%). In other words, theoriginal electromagnetic (EM) wave is “perfectly” absorbed and partly emitted as 90 -twisted EMwave, and the remaining is dissipated as heat.

Automatic Extraction of Liver Region from Medical Images by Using an MFUnet

Vo Thi Tuong Vi,오아란(A-Ran Oh),이귀상(Guee-Sang Lee),양형정(Hyung-Jeong Yang),김수형(Soo-Hyung Kim) 한국스마트미디어학회 2020 스마트미디어저널 Vol.9 No.3

This paper presents a fully automatic tool to recognize the liver region from CT images based on a deep learning model, namely Multiple Filter U-net, MFUnet. The advantages of both U-net and Multiple Filters were utilized to construct an autoencoder model, called MFUnet for segmenting the liver region from computed tomograph. The MFUnet architecture includes the autoencoding model which is used for regenerating the liver region, the backbone model for extracting features which is trained on ImageNet, and the predicting model used for liver segmentation. The LiTS dataset and Chaos dataset were used for the evaluation of our research. This result shows that the integration of Multiple Filter to U-net improves the performance of liver segmentation and it opens up many research directions in medical imaging processing field.

Comparative proteomics: assessment of biological variability and dataset comparability

Kim, Sa Rang,Nguyen, Tuong Vi,Seo, Na Ri,Jung, Seunghup,An, Hyun Joo,Mills, David A,Kim, Jae Han BioMed Central 2015 BMC bioinformatics Vol.16 No.-

<P><B>Background</B></P><P>Comparative proteomics in bacteria are often hampered by the differential nature of dataset quality and/or inherent biological deviations. Although common practice compensates by reproducing and normalizing datasets from a single sample, the degree of certainty is limited in comparison of multiple dataset. To surmount these limitations, we introduce a two-step assessment criterion using: (1) the relative number of total spectra (<I>R</I><SUB><I>TS</I></SUB>) to determine if two LC-MS/MS datasets are comparable and (2) nine glycolytic enzymes as internal standards for a more accurate calculation of relative amount of proteins. <I>Lactococcus lactis</I> HR279 and JHK24 strains expressing high or low levels (respectively) of green fluorescent protein (GFP) were used for the model system. GFP abundance was determined by spectral counting and direct fluorescence measurements. Statistical analysis determined relative GFP quantity obtained from our approach matched values obtained from fluorescence measurements.</P><P><B>Results</B></P><P><I>L. lactis</I> HR279 and JHK24 demonstrates two datasets with an <I>R</I><SUB><I>TS</I></SUB> value less than 1.4 accurately reflects relative differences in GFP levels between high and low expression strains. Without prior consideration of <I>R</I><SUB><I>TS</I></SUB> and the use of internal standards, the relative increase in GFP calculated by spectral counting method was 3.92 ± 1.14 fold, which is not correlated with the value determined by the direct fluorescence measurement (2.86 ± 0.42 fold) with the <I>p</I> = 0.024. In contrast, 2.88 ± 0.92 fold was obtained by our approach showing a statistically insignificant difference (<I>p</I> = 0.95).</P><P><B>Conclusions</B></P><P>Our two-step assessment demonstrates a useful approach to: (1) validate the comparability of two mass spectrometric datasets and (2) accurately calculate the relative amount of proteins between proteomic datasets.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s12859-015-0561-9) contains supplementary material, which is available to authorized users.</P>

Tuning of the Curie Temperature in La1-xSrxMn1-yTiyO₃

N. X. Phuc,N. T. Hieu,N. T. H. Le,D. H. Manh,N. A. Tuan,L. V. Hong,L. T. C. Tuong 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

Magnetic nanoparticles of La₁-xSrxMn₁-yTiyO₃ were prepared by using a sol-gel method, followed by annealing at various elevated temperatures. We found that the Curie temperature of the manganite nanoparticles could easily be tuned (from TC ~ 90 ℃ down to ~20 ℃) by substitution of nonmagnetic Ti⁴+ ions (from y = 0 to 7 %) for Mn. A comparison showed that the titanium substitution approach had advantages such as the phase transition being sharper and the magnetization remaining higher than in the case of the earlier known way of TC reduction by decreasing the Sr content from the optimal value of x = 0.3. The new features seem to make La1..xSrxMn₁..yTiyO₃ nanoparticles promising for hyperthermia application. Magnetic nanoparticles of La₁-xSrxMn₁-yTiyO₃ were prepared by using a sol-gel method, followed by annealing at various elevated temperatures. We found that the Curie temperature of the manganite nanoparticles could easily be tuned (from TC ~ 90 ℃ down to ~20 ℃) by substitution of nonmagnetic Ti⁴+ ions (from y = 0 to 7 %) for Mn. A comparison showed that the titanium substitution approach had advantages such as the phase transition being sharper and the magnetization remaining higher than in the case of the earlier known way of TC reduction by decreasing the Sr content from the optimal value of x = 0.3. The new features seem to make La1..xSrxMn₁..yTiyO₃ nanoparticles promising for hyperthermia application.

Synthesis of quinazolinones and benzazoles utilizing recyclable sulfated metal-organic framework-808 catalyst in glycerol as green solvent

Yen H. Vo,Thanh V. Le,Hieu D. Nguyen,Tuong A. To,Hiep Q. Ha,Anh T. Nguyen,Anh N.Q. Phan,Nam T.S. Phan 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.64 No.-

Zirconium-based metal-organic framework MOF-808 was synthesized, and sulfated with aqueous sulfuric acid. Sulfated MOF-808 was utilized as a recyclable heterogeneous catalyst for the synthesis of quinazolinones from β-ketoesters and benzamides, and for the synthesis of benzimidazoles from β-ketoesters and o-phenylenediamines in glycerol as a green solvent. The sulfated MOF-808 catalyst was more active than many heterogeneous and homogeneous catalysts. The combination of the sulfated MOF-808 and glycerol was also effective for the reaction of o-aminothiophenols with β-diketones or cyclic β-diketones to produce benzothiazoles. To our best knowledge, MOF-based catalysts were not previously utilized as heterogeneous catalyst in glycerol as green solvent.

Genome-wide average DNA methylation is determined <i>in utero</i>

Li, Shuai,Wong, Ee Ming,Dugué,, Pierre-Antoine,McRae, Allan F,Kim, Eunae,Joo, Ji-Hoon Eric,Nguyen, Tuong L,Stone, Jennifer,Dite, Gillian S,Armstrong, Nicola J,Mather, Karen A,Thalamuthu, Anbupal Oxford University Press 2018 International journal of epidemiology Vol.47 No.3

<P><B>Abstract</B></P><P><B>Background</B></P><P>Investigating the genetic and environmental causes of variation in genome-wide average DNA methylation (GWAM), a global methylation measure from the HumanMethylation450 array, might give a better understanding of genetic and environmental influences on methylation.</P><P><B>Methods</B></P><P>We measured GWAM for 2299 individuals aged 0 to 90 years from seven twin and/or family studies. We estimated familial correlations, modelled correlations with cohabitation history and fitted variance components models for GWAM.</P><P><B>Results</B></P><P>The correlation in GWAM for twin pairs was ∼0.8 at birth, decreased with age during adolescence and was constant at ∼0.4 throughout adulthood, with no evidence that twin pair correlations differed by zygosity. Non-twin first-degree relatives were correlated, from 0.17 [95% confidence interval (CI): 0.05–0.30] to 0.28 (95% CI: 0.08–0.48), except for middle-aged siblings (0.01, 95% CI: −0.10–0.12), and the correlation increased with time living together and decreased with time living apart. Spouse pairs were correlated in all studies, from 0.23 (95% CI: 0.3–0.43) to 0.31 (95% CI: 0.05–0.52), and the correlation increased with time living together. The variance explained by environmental factors shared by twins alone was 90% (95% CI: 74–95%) at birth, decreased in early life and plateaued at 28% (95% CI: 17–39%) in middle age and beyond. There was a cohabitation-related environmental component of variance.</P><P><B>Conclusions</B></P><P>GWAM is determined <I>in utero</I> by prenatal environmental factors, the effects of which persist throughout life. The variation of GWAM is also influenced by environmental factors shared by family members, as well as by individual-specific environmental factors.</P>

Broadband reflection of polarization conversion by 90° in metamaterial

Tuong, P. V.,Park, J. W.,Kim, Y. J.,Yoo, Y. J.,Lee, Y. P.,Rhee, J. Y.,Kim, K. W.,Nikitov, S. A.,Anh, N. H. T. 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.