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.

[ $^1H$ ] 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.

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.

Residual Multi-dilated convolution U-Net을 이용한 다중 심장 영역 분할 알고리즘 연구

임상헌 ( Sang-heon Lim ),최한승 ( H. S. Choi ),배희진 ( S. K. Jung ),정서경 ( J. K. Jung ),정진교 ( Myung-suk Lee ),이명숙 한국정보처리학회 2019 한국정보처리학회 학술대회논문집 Vol.26 No.1

본 연구에서는 딥 러닝을 이용하여 완전 자동화된 다중 클래스 전체 심장 분할 알고리즘을 제안하였다. 제안된 방법은 recurrent convolutional block과 residual multi-dilated block을 삽입하여 기존 U-Net을 개선한 인공신경망 모델을 사용하였다. 평가는 자동화 분석 결과와 수동 평가를 비교하였다. 그 결과 96.88%의 평균 DSC, 95.60%의 정확도, 97.00%의 recall을 얻었다. 이 실험 결과는 제안된 방법이 다양한 심장 구조에서 효과적으로 구분되어 수행되었음을 알 수 있다. 본 연구에서 제안된 알고리즘이 의사와 방사선 의사가 영상을 판독하거나 임상 결정을 내리는데 보조적 역할을 할 것을 기대한다.

과산화수소가 함유된 저산도 질산용액에서 DEHPA 추출제에 의한 Np 의 추출거동

이일희,양한범,김광욱,임재관,유재형 ( E . H . Lee,H . B . Yang,K . K . Kim,J . K . Lim,J . H . Yoo ) 한국공업화학회 1996 공업화학 Vol.7 No.4

본 연구는 Np의 환원제로 H₂O₂가 함유된 IM 이하의 저산도 질산용액으로부터 DEHPA(di-(2-ethyhexyl)phosphoric acid) 추출제에 의한 Np의 추출 및 역추출 조건 설정과 추출속도 향상에 주안점을 두어, 회분식으로 실험을 수행하였다. 저산도 질산용액에서 Np의 산화상태는 주로 Np(V)로 존재하고 있음을 확인하였으며, NP의 추출율은 H₂0₂농도 및 DEHPA의 농도 증가에 따라 증가하고, 질산농도 증가에 따라 급격히 감소하였다. 제3의 산화/환원제가 첨가되지 않는 경우 추출율은 약 70% 정도로 다소 낮지만, DEHPA에 의해 추출이 가능함을 보았다. 또한 추출속도는 H₂O₂농도의 0.516 승에 비례하며, 질산농도의 0.483 승에 반비례하고 있는 다음과 같은 식을 얻었다. d[Np(V)]/dt=-1.391×10^(-2)[H₂O₂]^(0.516)[HNO₃]^(-0.483) [Np(V)] 그리고 과산화수소의 첨가 유무에 관계없이, 유기상으로 추출된 Np은 옥살산(oxalic acid)에 의해 효과적으로 역추출되었으며, 0.5M 옥살산으로 약 92% 이상을 역추출하였다. Extraction behaviour of Np with DEHPA(di-(2-ethyhexyl) phosphoric acid) from the low nitric acid solution(below 1M HNO₃) containing H₂O₂as a reducing agent was studied at a batch system in order to establish the conditions of extraction and stripping and to enhance the extraction rate. As results, it was confirmed that the Np was mainly the pentavalent oxidation state in the low nitric acid solution. The extraction yield of Np was increased with increasing the concentration of DEHPA and H₂O₂and decreased more rapidly with the increase of HNO₃ concentration. It was also found that the Np could be extracted into DEHPA even without the addition any redox agents, although the extraction yield is rather low as about 70%. The extraction rate was proportional to the 0.516 power of H₂O₂concentration and inversely proportional to 0.483 power of HNO, concentration as follows. d[Np(V)]/dt=-1.391×10^(-2)[H₂O₂]^(0.516)[HNO₃]^(-0.483) [Np(V)] Regardless of the H₂O₂, the Np extracted in the organic phase was effectively stripped to the aqueous phase with H₂C₂O₄. The Np could be stripped more than 92% with 0.5M H₂C₂O₄.

Intranasal Immunization of Pigs against Influenza with Synthetic Peptides Based on the Cassette Theory

Lim, Y.K.,Okazaki, K.,Matsuki, S.,Ogasawara, K.,Kida, H.,Lee, Y. S. 濟州大學校 農科大學 動物科學硏究所 1998 動物科學論叢 Vol.13 No.1

Synthetic petide vaccines prepared according to the cassette theory(Naruse et al., 1994), formalin-inactivated virus and ether-split vaccine of influenza virus A/Aichi/68(H3N2) were administered intranasally to the pigs. The peptide vac-cines contained single or double sets of the peptide sequence of hemagglutinin 127-133 of influenza virus A/Aichi/2/68(H3N2) inserted into the H-2 class allele specific amino acid motif of the agretope composed of residues 43-58 of pigeon cytochrome c in the mouse bearing A^(k) or A^(b). After 4 times immuniza- tion, pigs were challenged with 10^(4-5) PFU of virus intranasally. Intranasal immunization of the pigs with inactivated virus vaccine and split virus vaccine induced antibody production against A/Aichi/2/68( H3N2) virus, protecting them from infection. Synthetic peptide vaccine which contains 2 sets of epitope amino acid sequence evoked protective immune response although antibody response was not detected in the pigs. The present results indicated that intranasal route can be applied for inducing not only mucosal immunity but also systemic immunity against influenza virus infection. Based on the present finding we assume that synthetic peptide vaccine prepared according to Cas-sette theory may be applicable to the heterogenous species including human.

Effect of Curing Time on the Physicochemical and Sensory Properties of Beef Jerky Replaced Salt with Soy Sauce, Red Pepper Paste and Soybean Paste

Lim, H.J.,Kim, G.D.,Jung, E.Y.,Seo, H.W.,Joo, S.T.,Jin, S.K.,Yang, H.S. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.8

This study was done to investigate the quality properties of beef jerky with soy sauce, red pepper paste, and soybean paste replacing salt. Sliced beef samples were cured in salt (control), soy sauce, red pepper paste, and soybean paste for 24 or 48 h and then dried at $70^{\circ}C$ for 8 h. Treatments showed higher final moisture content and lower $Na^+$ concentration than the control after drying for 8 h. The lightness and shear force values were lower in all treatment samples than in the control during 48 h of curing time. In particular, lower lipid oxidation was found in the jerky cured with red pepper paste than in the control. Sensory evaluation showed that color, flavor, and tenderness of jerky samples were improved by replacing salt with soy sauce, red pepper paste and soybean paste, and higher likeability scores of the beef jerky were obtained among those treatments after 48 h of curing time.

Live attenuated nephropathogenic infectious bronchitis virus vaccine provides broad cross protection against new variant strains.

Lim, T-H,Kim, M-S,Jang, J-H,Lee, D-H,Park, J-K,Youn, H-N,Lee, J-B,Park, S-Y,Choi, I-S,Song, C-S Poultry Science Association, etc 2012 Poultry science Vol.91 No.1

<P>Infectious bronchitis virus (IBV) infections cause great economic losses to the poultry industry worldwide, and the emergence of new variant strains complicates disease control. The present study investigated the genetic and protectotypic features of newly emerged Korean IBV strains. A phylogenetic analysis showed that several recent isolates formed 2 different clusters (new cluster 1 and 2), which were distinct from other preexisting clusters. New cluster 1 IBV strains represented recombinants between Korean nephropathogenic strain KM91 and the QXIBV strain. New cluster 2 IBV strains showed low amino acid homology (<58.7%) compared with previous isolates. We evaluated the protective efficacy of commercial IBV vaccines (H120 and K2 strain) against these new isolates. In cross-protection studies, the H120 strain did not provide sufficient protection against these variants. However, highly attenuated nephropathogenic IBV vaccine, K2 strain, provided significantly higher levels of protection against variants compared with chickens vaccinated with H120 (P < 0.05 or better). These results indicate that the K2 vaccine could be helpful for the reduction of economic losses caused by newly evolving IBV recombinants (new cluster 1) and variants (new cluster 2).</P>

A novel canine influenza H3N2 virus isolated from cats in an animal shelter

Jeoung, H.Y.,Lim, S.I.,Shin, B.H.,Lim, J.A.,Song, J.Y.,Song, D.S.,Kang, B.K.,Moon, H.J.,An, D.J. Elsevier Scientific Pub. Co 2013 Veterinary microbiology Vol.165 No.3

The interspecies transmission of avian-origin H3N2 canine influenza virus (CIV) to dogs was first reported in 2007. The present study characterized a novel CIV H3N2 isolated from cats in an animal shelter. A comparative analysis of the deduced amino acid sequences of the A/Canine/Korea/CY009/2010(H3N2) (CY009) and A/Feline/Korea/FY028/2010 (H3N2) (FY028) strains isolated from dogs and cats, respectively, in the animal shelter identified point mutations in 18 amino acid positions within eight viral genes. Interestingly, CY009 and FY028 replicated well in specific pathogen-free embryonated chicken eggs and in mice, respectively. Mice infected with the FY028 strain exhibited significant over expression of IL-10, TNF-α, and IFN-γ (p<0.001) at 3 days postinfection. Thus, an emergency monitoring system should be developed to identify influenza mutations that occur during interspecies transmission in companion animals and for continuous public health surveillance.

Pharmacokinetics of prothionamide in patients with multidrug-resistant tuberculosis.

Lee, H W,Kim, D W,Park, J H,Kim, S-D,Lim, M-S,Phapale, P B,Kim, E-H,Park, S K,Yoon, Y-R The Union 2009 The international journal of tuberculosis and lung Vol.13 No.9

<P>SETTING: National Masan Tuberculosis Hospital, Masan, South Korea. OBJECTIVE: To evaluate the pharmacokinetics of prothionamide (PTH) in South Korean patients with multidrug-resistant tuberculosis (MDR-TB) and to investigate whether differences in body mass index (BMI) could explain observed differences in PTH disposition. DESIGN: Seventeen patients participated in the study; all had MDR-TB and had received combination anti-tuberculosis treatment, including PTH, cycloserine, ofloxacin, para-aminosalicylic acid and streptomycin or kanamycin, for at least 2 weeks. The patients were divided into two groups based on BMI: Group A (18.5 < or = BMI<23), and Group B (BMI<18.5). Serum samples were collected over 24 h, and the plasma PTH concentration was determined by a validated high-performance liquid chromatography assay. RESULTS: After steady-state administration of PTH, the mean area under the plasma concentration-time curve from time 0 to 12 h (AUC(0-12h)) was 11.0 +/- 3.7 microg h/ml. The mean T(max) and t(1/2) were respectively 3.6 h and 2.7 h. No significant difference in PTH disposition was observed between groups A and B, except for ke and t(1/2). CONCLUSION: In the pharmacokinetic parameter estimates for PTH in MDR-TB patients during routine treatment, the pharmacokinetics of PTH did not appear to correlate with extent of emaciation in MDR-TB patients.</P>