1H NMR Measurements of the Phase Transition of (NH₄)₃H(SO₄)₂ Single Crystals

S. H. Choi,Moohee Lee,Ae Ran Lim,K. S. Han,S. K. Kwon,S. K. Nam 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.2

$^1$H nuclear magnetic resonance (NMR) experiments have been performed in the temperature range of 30 -- 300 K at 7 T to investigate the phase-dependent nature of the dynamic network of hydrogen bonds in a ((NH₄)₃H(SO₄)₂ single crystal. The crystal has six phases, which are ferroelectric, antiferroelectric, incommensurate, antiferroelectric, ferroelastic, and superionic with the respective transition temperatures of 63, 133, 139, 256 and 413 K. The spin-lattice relaxation time, T₁, of ¹H NMR is similar for the ammonium protons and the hydrogen-bond protons over the entire range of experimental temperatures. The T₁, of ¹H NMR gradually decreases down to 120 K and starts to steeply increase below 100 K. Then, the T₁ shows an abrupt decrease below 68 K with a sharp minimum at 63 K, where the ferroelectric transition occurs. The ¹H NMR spectrum shifts to the high-frequency side at temperatures below 63 K due to the ferroelectric phase transition. This behavior of the T₁ and the spectrum confirms a dramatic change in the dynamics of hydrogen bonds associated with the ferroelectric phase transition at 63 K. $^1$H nuclear magnetic resonance (NMR) experiments have been performed in the temperature range of 30 -- 300 K at 7 T to investigate the phase-dependent nature of the dynamic network of hydrogen bonds in a ((NH₄)₃H(SO₄)₂ single crystal. The crystal has six phases, which are ferroelectric, antiferroelectric, incommensurate, antiferroelectric, ferroelastic, and superionic with the respective transition temperatures of 63, 133, 139, 256 and 413 K. The spin-lattice relaxation time, T₁, of ¹H NMR is similar for the ammonium protons and the hydrogen-bond protons over the entire range of experimental temperatures. The T₁, of ¹H NMR gradually decreases down to 120 K and starts to steeply increase below 100 K. Then, the T₁ shows an abrupt decrease below 68 K with a sharp minimum at 63 K, where the ferroelectric transition occurs. The ¹H NMR spectrum shifts to the high-frequency side at temperatures below 63 K due to the ferroelectric phase transition. This behavior of the T₁ and the spectrum confirms a dramatic change in the dynamics of hydrogen bonds associated with the ferroelectric phase transition at 63 K.

Solubility of oxcarbazepine in eight solvents within the temperature range T=(288.15-308.15)K

Nam, K.,Ha, E.S.,Kim, J.S.,Kuk, D.H.,Ha, D.H.,Kim, M.S.,Cho, C.W.,Hwang, S.J. Academic Press 2017 The Journal of chemical thermodynamics Vol.104 No.-

In this study, the solubility of oxcarbazepine in pure methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, acetone, acetonitrile, and tetrahydrofuran was analysed across the temperature range of 288.15-308.15K under atmospheric pressure by using a solid-liquid equilibrium method. The experimental values obtained data were correlated using the modified Apelblat model at each temperature. The mole fraction solubility of oxcarbazepine in all eight pure solvents increased gradually in a temperature-dependent manner. The highest mole fraction solubility of 3.08x10<SUP>-3</SUP> at 308.15K was observed for tetrahydrofuran, followed by acetone (1.82x10<SUP>-3</SUP> at 308.15K), acetonitrile (1.22x10<SUP>-3</SUP> at 308.15K), methanol (1.11x10<SUP>-3</SUP> at 308.15K), ethanol (6.17x10<SUP>-4</SUP> at 308.15K), 1-butanol (6.17x10<SUP>-4</SUP> at 308.15K), 1-propanol (6.16x10<SUP>-4</SUP> at 308.15K), and 2-propanol (4.13x10<SUP>-4</SUP> at 308.15K). The experimental solubility in all solvents correlated well with that calculated using the modified Apelblat equation across the temperature range of (288.15-308.15)K. Therefore, the experimental solubility and correlation equations established in this study could be useful during the crystallization/purification, pre-formulation, and formulation stages of oxcarbazepine production in laboratories and related industries.

1H Nuclear Magnetic Resonance study of Ferroelectric (NH4)3H(SO4)2

S. H. Choi,K. S. Han,S. K. Kwon,S. K. Nam,H. H. Choi,Moohee Lee,Ae Ran Lim 한국자기공명학회 2007 Journal of the Korean Magnetic Resonance Society Vol.11 No.2

1H nuclear magnetic resonance (NMR) experiments have been performed at 30 - 300 K and 7 T to investigate dynamics of hydrogen bond network in the single crystal (NH4)3H(SO4)2. The two proton sites, ammonium proton and hydrogen-bond proton, are identified from the 1H NMR MAS spectrum at 340 K. As temperature decreases, the 1H NMR spectrum shifts to the higher frequency side with a larger linewidth. The spectrum at 65 K shows a distinctive change in line shape toward the ferroelectric transition at 63 K. The measured values of T1 for ammonium and hydrogen-bond protons are similar in the whole range of temperature. T1 of 1H NMR shows a gradual decrease down to 120 K and starts to steeply increase below 100 K. Then T1 shows abrupt decrease below 70 K with a sharp minimum at 63 K, where the ferroelectric transition occurs. This temperature dependence of spectrum and T1 clearly prove that the large change in the dynamics of hydrogen bond network is associated with the ferroelectric phase transition at 63 K.

S6K1 Phosphorylation of H2B Mediates EZH2 Trimethylation of H3: A Determinant of Early Adipogenesis

Yi, S.,Um, S.,Lee, J.,Yoo, J.,Bang, S.,Park, E.,Lee, M.,Nam, K.,Jeon, Y.,Park, J.,You, J.,Lee, S.J.,Bae, G.U.,Rhie, J.,Kozma, Sara C.,Thomas, G.,Han, J.W. Cell Press 2016 Molecular Cell Vol.62 No.3

S6K1 has been implicated in a number of key metabolic responses, which contribute to obesity. Critical among these is the control of a transcriptional program required for the commitment of mesenchymal stem cells to the adipocytic lineage. However, in contrast to its role in the cytosol, the functions and targets of nuclear S6K1 are unknown. Here, we show that adipogenic stimuli trigger nuclear translocation of S6K1, leading to H2BS36 phosphorylation and recruitment of EZH2 to H3, which mediates H3K27 trimethylation. This blocks Wnt gene expression, inducing the upregulation of PPARγ and Cebpa and driving increased adipogenesis. Consistent with this finding, white adipose tissue from S6K1-deficient mice exhibits no detectable H2BS36 phosphorylation or H3K27 trimethylation, whereas both responses are highly elevated in obese humans or in mice fed a high-fat diet. These findings define an S6K1-dependent mechanism in early adipogenesis, contributing to the promotion of obesity.

[ $^1H$ ] Nuclear Magnetic Resonance Study of Ferroelectric $(NH_4)_3H(SO_4)_2$

Choi, S.H.,Han, K.S.,Kwon, S.K.,Nam, S.K.,Choi, H.H.,Lee, Moo-Hee,Lim, Ae-Ran Korean Magnetic Resonance Society 2007 Journal of the Korean Magnetic Resonance Society Vol.11 No.2

[ $^1H$ ] nuclear magnetic resonance (NMR) experiments have been performed at 30 - 300 K and 7 T to investigate dynamics of hydrogen bond network in the single crystal $(NH_4)_3H(SO_4)_2$. The two proton sites, ammonium proton and hydrogen-bond proton, are identified from the $^1H$ NMR MAS spectrum at 340 K. As temperature decreases, the $^1H$ NMR spectrum shifts to the higher frequency side with a larger linewidth. The spectrum at 65 K shows a distinctive change in line shape toward the ferroelectric transition at 63 K. The measured values of $T_1$ for ammonium and hydrogen-bond protons are similar in the whole range of temperature. $T_1$ of $^1H$ NMR shows a gradual decrease down to 120 K and starts to steeply increase below 100 K. Then $T_1$ shows abrupt decrease below 70 K with a sharp minimum at 63 K, where the ferroelectric transition occurs. This temperature dependence of spectrum and $T_1$ clearly prove that the large change in the dynamics of hydrogen bond network is associated with the ferroelectric phase transition at 63 K.

한국인 Long Term Non Progressors로부터 분리된 HIV-1 env 및 nef 유전자와 이들의 면역 유전학적 특성 분석에 의한 질병진전 요인 규명

이주실,강춘,김성순,박근용,고운영,기미경,최병선,남정구,서순덕,이성래,구본기,박혜경,도경미,김태규,최희백,조현일,김요숙,김지영,이해정,안수진 국립보건연구원 1999 국립보건원보 Vol.36 No.-

煙草赤星病과 施肥量과의 關係에 關한 硏究

南基桓,沈在燮 충북대학교 엽연초연구소 1974 煙草硏究 Vol.2 No.-

This experiment was carried out in order to observe the effects three elements of fertilizer(N.,P.,K.,) on the infection of tobacco brown spot disease. The plots were designed by split plot method with 8 treatment (A: check, B: 50% added applied N., P. and K., C: 50% subatracted applied three elements., D: 50% added applied N., E: 50% added applied P., F: 50% added applied P., G: no applied P., G: an applied P: and H: no applied P.). Check is N 14kg P2O5 21kg and K3O 28kg per 10 are respectively. Y.S.A was employed for sample variety and transplanted on 15 May. The results obtained as follow; 1) There were no differences among the plots (treatments) during the early growing stages. 2) The plot of 1½N, no K. and 1½N.P.K. have shown larger number of lesions than the check respectively. 3) The plot of 1/2 N.P.K.(C), 1½K(F), and no P.(G) have shown almost no differences in the rate of disease occurence as compared with check (A). In conclusion, excess application of N. and defficiency of K. seemed to be related with tobacco brown spot disease infection.

Al₂O₃/SiC 세라믹스 균열치유능력에 미치는 첨가제 양의 영향

박성원(S. W. Park),안석환(S. H. Ahn),손창석(C. S. Son),김성광(S. K. Kim),남기우(K. W. Nam) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.10

The four kinds of Al₂O₃ composite ceramics were prepared using a mixture of 85 wt.% Al₂O₃ (mean size 0.5 μm), 15 wt.% SiC powder with Y₂O₃ as an additive powder (0, 1, 3 and 5 wt.%). The crack-healing strengths were studied as functions of crack-healing temperature and amount of Y₂O₃. The in-situ crack-healing behavior was observed at 1,573 K for 1 h in the air. The heat treated specimen with 3 wt.% of Y₂O₃ showed better crack-healing ability than specimen with 1 or 5 wt.% of Y₂O₃. In case of specimen with 3 wt.% of Y₂O₃, the bending strength of the crack-healed specimen at 1,473 K was recovered to the bending strength of smooth specimen treated at 1573 K. The heat-resistance limit temperature of Al₂O₃ composite ceramics was 1,073 K, 1,373 K, 873 K for the specimen with 1, 3, 5 wt.% of Y₂O₃.

Development of Naturally Degradable “Rice Polymer" For Organic Weed Management of Red Pepper and Rice

C.K. Kang,H.S. Nam,Y.K. Lee,S.B. Lee,B.M. Lee,Y.J. Oh,H.J. Jee,M.K. Hong,K.W. Jung,Y.J. Lee,Y.H. Choi 한국유기농업학회 2011 韓國有機農業學會誌 Vol.19 No.S

Among the developed bío-degradable polymer fílms as compared wíth transparent fílm(Whíte), black polymer fílm was sígnífícantly more effectíve for controllíng weeds ín red pepper. Also, we found that whíte and black polymer mulchíng had 81.8% and 97.9% of managing weed controllíng effects in rice, respectively. Compared to nonmulched rice paddy with water supply, the non-mulched rice paddy wíthout any water supply has stopped its growth at 41 days after transplantíng, whíle polymer -mulched rice paddy without water supply had about 60% of normally growing rice plants. This shows the polymer treatment has a remarkable effect on water and power saving, solution of herbicidal resistance, avoidance of herbícidal influence to eco-system etc. When the naturally decomposíng polymer was used, a temperature was elevated as high as 4.7 ℃ on maximum and 2.6 ℃ on average. Also the naturally decomposing polymer accelerated rooting by 7 days and lowered a stress level from transplanting. The weed control effect mulched by polymer was remarkable as 98. 7%. The p이ymer now, after 294 days treated on the rice paddy, has been completely decomposed.

<i>CYP2A6</i> and <i>ERCC1</i> polymorphisms correlate with efficacy of S-1 plus cisplatin in metastatic gastric cancer patients

Park, S R,Kong, S-Y,Nam, B-H,Choi, I J,Kim, C G,Lee, J Y,Cho, S J,Kim, Y W,Ryu, K W,Lee, J H,Rhee, J,Park, Y-I,Kim, N K Nature Publishing Group 2011 The British journal of cancer Vol.104 No.7

<P><B>Background:</B></P><P>We evaluated the association between polymorphisms of cytochrome P450 2A6 (<I>CYP2A6</I>)/excision repair cross-complementation group 1 (<I>ERCC1</I>)/X-ray repair cross-complementing group 1(<I>XRCC1</I>) and treatment outcomes of metastatic gastric cancer (MGC) patients treated with S-1/cisplatin.</P><P><B>Methods:</B></P><P>Among MGC patients (<I>n</I>=108), who received S-1 (40 mg m<SUP>−2</SUP> b.i.d., days 1–14) and cisplatin (60 mg m<SUP>−2</SUP>, day 1) every 3 weeks, we analysed the wild-type allele (<I>W</I>) and variants (<I>V</I>) of <I>CYP2A6</I> (<I>*4</I>, <I>*7, *9, *10</I>), and the polymorphisms of <I>ERCC1</I> (rs11615, rs3212986) and <I>XRCC1</I> (rs25487).</P><P><B>Results:</B></P><P>Patients having fewer <I>CYP2A6</I> variants had better response rates (<I>W</I>/<I>W vs W</I>/<I>V</I> other than <I>*1/*4 vs V</I>/<I>V</I> or <I>*1/*4</I>=66.7 <I>vs</I> 58.3 <I>vs</I> 32.3% <I>P</I>=0.008), time to progression (TTP) (7.2 <I>vs</I> 6.1 <I>vs</I> 3.5 months, <I>P</I>=0.021), and overall survival (23.2 <I>vs</I> 15.4 <I>vs</I> 12.0 months, <I>P</I>=0.004). <I>ERCC1 19442C</I>><I>A</I> (rs3212986) was also associated with response rate (<I>C/C</I>, 46.7% <I>vs C/A</I>, 55.3% <I>vs A/A</I>, 87.5%) (<I>P</I>=0.048) and TTP (4.4 <I>vs</I> 7.6 <I>vs</I> 7.9 months) (<I>P</I>=0.012). Patients carrying both risk genotypes of <I>CYP2A6</I> (<I>V</I>/<I>V</I> or <I>1/*4</I>) and <I>ERCC1 19442C</I>><I>A</I> (<I>C/C</I>) <I>vs</I> those carrying none showed an adjusted odds ratio of 0.113 (<I>P</I>=0.004) for response, and adjusted hazard ratios of 3.748 (<I>P</I>=0.0001) for TTP and 2.961 (<I>P</I>=0.006) for death.</P><P><B>Conclusion:</B></P><P>Polymorphisms of <I>CYP2A6</I> and <I>ERCC1 19442C</I>><I>A</I> correlated with the efficacy of S-1/cisplatin.</P>