Relationship Between K_trans and K₁ with Simultaneous Versus Separate MR/PET in Rabbits with VX2 Tumors

Lee, K. H.,Kang, S. K.,Goo, J. M.,Lee, J. S.,Cheon, G. J.,Seo, S.,Hwang, E. J. INTERNATIONAL INSTITUTE OF ANTICANCER RESEARCH 2017 Anticancer research Vol.37 No.3

<P>Background/Aim: To compare the relationship between Ktrans from DCE-MRI and K1 from dynamic (NNH3)-N-13- PET, with simultaneous and separate MR/PET in the VX-2 rabbit carcinoma model. Materials and Methods: MR/PET was performed simultaneously and separately, 14 and 15 days after VX-2 tumor implantation at the paravertebral muscle. The Ktrans and K-1 values were estimated using an in-house software program. The relationships between Ktrans and K-1 were analyzed using Pearson's correlation coefficients and linear/non-linear regression function. Results: Assuming a linear relationship, Ktrans and K-1 exhibited a moderate positive correlations with both simultaneous ( r=0.54-0.57) and separate ( r=0.53-0.69) imaging. However, while the Ktrans and K-1 from separate imaging were linearly correlated, those from simultaneous imaging exhibited a non-linear relationship. The amount of change in K-1 associated with a unit increase in Ktrans varied depending on Ktrans values. Conclusion: The relationship between K-trans and K-1 may be mis-interpreted with separate MR and PET acquisition.</P>

A Design of Transferable Sample Holder for Resistive Heating and Conductive Cooling

Seo, J.M.,Kim, K.J.,Ihm, S.,Koo, S.J.,Park, Ch.,Kim, Y.K. 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

통전가열, 접촉냉각, 전기적 bias 및 시료 교환을 자유로이 할 수 있는 다기능의 새롭고 간단한 시료 고정장치를 저온 및 초고진공 상태에서 기체와 여러 방향의 시료표면 사이의 상호작용을 연구하기 위하여 고안하였다. 이 장치로써 2분 이내에 기판의 온도를 1600 K에서 20 K로 2분 이내에 냉각시킬 수 있었다. 그러므로 청결한 표면위에 수소나 He이나 Ne을 제외하고는 대부분의 기체를 흡착시킬 수 있게 되었다. 이러한 장치는 표면에서의 상변화, 기체와 표면의 화학반응의 연구에 중요하게 활용될 수 있다. A simple and novel sample-holder which has multi-functions of resistive heating, conductive cooling, electrical biasing and sample exchanging has been designed in order to inverstigate gas-surface interations for various surface direction under ultrahigh vacuum and low temperature. It has been proved that the wafer can be cooled from 1600 K to 20 K within two minutes. Therefore the controlled adsorption of most gases, except H, He and Ne, were possible on the clean surfaces. The design has substantial applocations in areas like surface phase transitions and gas-surface chemical reactions.

고온기 초지의 예취관리에 관한 연구 6 . 고온기간중 예취높이와 질소 및 칼리추비가 혼파초지의 식생과 수량 및 목초품질에 미치는 영향

서성(S . Seo),조무환(M . H . Jo),박문수(M . S . Park),이종경(J . K . Lee),한영춘(Y . C . Han) 한국축산학회 1988 한국축산학회지 Vol.30 No.8

A field experiment was carried out to determine the effects of cutting height at the third cut and application of N and K₂O after cutting during mid-summer season on the soil temperature, plant height, grass coverage, percentages of grass and legume, yield and grass quality in orchardgrass dominated pasture. With three cutting heights (3, 6 and 9㎝) and 4 fertilizer levels (0, N 50㎏, K₂O 50㎏, and N 50㎏ + K₂O 50㎏ ㏊^(-1)), present experiment was conducted at Livestock Experiment Station, Suwon in 1987. 1. The soil temperature after the third cut was rapidly elevated, and lower value was observed with 9㎝ of cutting height through the regrowth period. Plant height after cutting was remarkably increased with higher stubble height regardless of fertilizer levels. 2. The grass coverage and percentage of grass were increased as stubble height was high, while the influence of fertilizer on those was very little. Application of N and K₂O with lower stubble height significantly increased the percentage of bareland. 3. The yield at the third cut was decreased with higher height. But the regrowth yield was significantly increased as the cutting height was increased regardless of fertilizer levels. Regrowth yield was great at N 50㎏ + K₂O 50㎏ $gt; 0 $gt; K₂O 50㎏, N 50㎏, in that order. However, there were not significantly different on regrowth yield among fertilizer treatment. 4. The contents of crude protein, crude fat, crude ash, P, K and Ca were decreased as stubble height was high, and that of crude fiber was increased at 9 ㎝ cutting height. Also the influence of N and K₂O fertilizer on grass quality was little.

15-Deoxy-Δ^12,14-prostaglandin J₂ prevents oxidative injury by upregulating the expression of aldose reductase in vascular smooth muscle cells

Kang, E. S.,Hwang, J. S.,Ham, S. A.,Park, M. H.,Kim, G. H.,Paek, K. S.,Yoo, T.,Lee, W. J.,Kang, K. R.,Lee, J. H.,Choi, Y. J.,Seo, H. G. Informa Healthcare 2014 Free radical research Vol.48 No.2

<P>The omega-6 fatty acid derivative 15-Deoxy-Δ<SUP>12,14</SUP>-prostaglandin J<SUB>2</SUB> (15d-PGJ<SUB>2</SUB>) is believed to play a role in cellular protection against oxidative stress in diverse cell systems. However, the cellular mechanisms by which protection is afforded by 15d-PGJ<SUB>2</SUB> are not fully elucidated in vascular smooth muscle cells (VSMCs). In this study, we report the finding that 15d-PGJ<SUB>2</SUB> elicited a time and concentration- dependent increase in aldose reductase (AR) expression. This induction was independent of the activation of peroxisome proliferator- activated receptor γ. Inhibition of phosphatidylinositol 3-kinase (PI3K) significantly suppressed the increase in expression and promoter activity of AR induced by 15d-PGJ<SUB>2</SUB>. Luciferase reporter assays demonstrated that 15d-PGJ<SUB>2</SUB> targets the multiple stress response regions comprising the antioxidant response element in the promoter of the AR gene. 15d-PGJ<SUB>2</SUB>-mediated induction of AR promoter activity was potentiated in the presence of nuclear factor-erythroid 2-related factor 2 (Nrf2), but not in cells expressing dominant negative Nrf2. Cells treated with 15d-PGJ<SUB>2</SUB> were resistant to oxidant-induced apoptotic cell death by inhibiting production of reactive oxygen species. These effects were significantly attenuated in the presence of an AR inhibitor or small interfering RNA against AR, indicating that AR plays a protective role against oxidative injury. Taken together, these findings demonstrate that activation of PI3K by 15d-PGJ<SUB>2</SUB> increases the expression of AR through Nrf2, and increased AR activity may function as an important cellular response against oxidative injury.</P>

Lentibacillus kimchii sp. nov., an extremely halophilic bacterium isolated from kimchi, a Korean fermented vegetable

Oh, Y. J.,Lee, H. W.,Lim, S. K.,Kwon, M. S.,Lee, J.,Jang, J. Y.,Lee, J. H.,Park, H. W.,Nam, Y. D.,Seo, M. J. Springer Science + Business Media 2016 Antonie van Leeuwenhoek Vol.109 No.6

<P>A Gram-positive, aerobic, non-motile and extremely halophilic bacterial strain, designated K9(T), was isolated from kimchi, a Korean fermented food. The strain was observed as endospore-forming rod-shaped cells showing oxidase and catalase activity. It was found to grow at 10.0-30.0 % (w/v) NaCl (optimum, 15.0-20.0 %), pH 7.0-8.0 (optimum, pH 7.5) and 15-40 A degrees C (optimum, 30 A degrees C). The polar lipids of strain K9(T) were identified as phosphatidylglycerol, three unidentified phospholipids and an unidentified glycolipid. The isoprenoid quinone was identified as menaquinone-7. The major cellular fatty acids (> 20 % of the total) were found to be anteisio-C-15:0 and anteisio-C-17:0. The cell wall peptidoglycan composition was determined to contain meso-diaminopimelic acid. The G + C content of genomic DNA was determined to be 48.2 mol %. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the isolated strain is closely related to Lentibacillus salinarum AHS-1(T) (96.7 % sequence similarity). Based on its phenotypic, chemotaxonomic and phylogenetic data, strain K9(T) is considered to represent a novel species of the genus Lentibacillus, for which the name Lentibacillus kimchii sp. nov., is proposed. The type strain is K9(T) (=KACC 18490(T) = JCM 30234(T)).</P>

TMEM175 Is an Organelle K⁺ Channel Regulating Lysosomal Function

Cang, C.,Aranda, K.,Seo, Y.j.,Gasnier, B.,Ren, D. Cell Press ; MIT Press 2015 Cell Vol.162 No.5

Potassium is the most abundant ion to face both plasma and organelle membranes. Extensive research over the past seven decades has characterized how K<SUP>+</SUP> permeates the plasma membrane to control fundamental processes such as secretion, neuronal communication, and heartbeat. However, how K<SUP>+</SUP> permeates organelles such as lysosomes and endosomes is unknown. Here, we directly recorded organelle K<SUP>+</SUP> conductance and discovered a major K<SUP>+</SUP>-selective channel K<SUB>EL</SUB> on endosomes and lysosomes. K<SUB>EL</SUB> is formed by TMEM175, a protein with unknown function. Unlike any of the ~80 plasma membrane K<SUP>+</SUP> channels, TMEM175 has two repeats of 6-transmembrane-spanning segments and has no GYG K<SUP>+</SUP> channel sequence signature-containing, pore-forming P loop. Lysosomes lacking TMEM175 exhibit no K<SUP>+</SUP> conductance, have a markedly depolarized ΔΨ and little sensitivity to changes in [K<SUP>+</SUP>], and have compromised luminal pH stability and abnormal fusion with autophagosomes during autophagy. Thus, TMEM175 comprises a K<SUP>+</SUP> channel that underlies the molecular mechanism of lysosomal K<SUP>+</SUP> permeability.

Solvent-induced mono- and diplatinum(II) complexes of O₃S₂-macrocycle

Seo, J.,Park, K.M.,Yoon, I.,Kim, H.J.,Lee, S.S. Elsevier 2008 INORGANIC CHEMISTRY COMMUNICATIONS Vol.11 No.8

The reactions of O<SUB>3</SUB>S<SUB>2</SUB>-macrocycle L with K<SUB>2</SUB>PtCl<SUB>4</SUB> afforded mono- (1) or dinuclear (2) complexes depending on the solvent used. From the X-ray crystal structures, it is confirmed that one water molecule stabilizes the diplatinum complex 2 via hydrogen bond.

K-band frequency-selective limiter using an injection locked oscillator for blocker cancellation

Choi, K.,Jung, J.,Park, H.,Seo, T.,Jeong, J.,Kwon, Y. Institution of Electrical Engineers 2018 Electronics letters Vol.54 No.7

<P>A frequency-selective limiter (FSL) using an injection locked oscillator (ILO) is proposed for a blocker cancellation, which employs an ILO in the feedforward path as a high-Q notch filter to select and amplify the blocker from the input signal. The ILO also functions as a phase shifter providing a proper phase delay so that two blockers in the feedforward and thru paths cancel each other out in the combining node. The proposed FSL is fabricated in a commercial 0.15 mu m GaAs pHEMT process with a maximum blocker suppression of 27 dB in the 50 MHz spacing two-tone measurement at the K-band. Thus, it provides a blocker suppression higher than 20 dB over the 250 MHz blocker bandwidth.</P>

A Case of Letterer-Siwe Disease

Lee, Y. J 大韓皮膚科學會 1995 大韓皮膚科學會誌 Vol.33 No.5

Existence of metastable molecular precursors to dissociative oxygen chemisorption on Si(111) and Si(100) at 40 K

Seo, J. M.,Kim, K. J.,Yeom, H. W.,Park, Ch. 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.17 No.-

The presence of metastable molecular precursor to dissociative oxygen chemisorption has been identified, for the first time, on Si(100) and Si(111) surfaces using ultraviolet photoelectron spectroscopy and x-ray photoelectron spectroscopy at 40 K. Density of valence states for such species shows three distinct peaks at 1.8, 3.4, and 4.9 eV below the Fermi energy of substrates. The precursor stabilized on Si(100) at 40 K induces a large work- function increase of 1.5 eV at saturation coverage. It also gives rise to a shoulder to O 1s photoemission spectrum that it located at 1.2 eV lower binding energy than the O 1s peak of stable and dissociated oxygen species. It has been concluded that the major reason of a larger work-function increment at 40 K is the existence of a molecular precursor, or peroxy radical type, on Si(100) and Si(111). These results strongly suggest that exists a general mechanism of oxygen adsorption onto silicon surfaces.