K₂WO₄ flux 에 의한 K₂Oㆍ6TiO₂ whisker 의 합성

이진식 ( J. S. Lee ),이상문 ( S. M. Lee ),이철태 ( C. T. Lee ),권긍택 ( K. T. Kohn ),김영명 ( Y. M. Kim ) 한국공업화학회 1993 한국공업화학회 연구논문 초록집 Vol.1993 No.0

K₂Oㆍ6TiO₂ whisker는 구조적인 특성 때문에 물리ㆍ화학적으로 매우 안정하며 보강재, 마찰재, 단열재 등의 많은 용도를 갖게된다. 특히 최근에는 석면이 발암물질로 인한 자동차 브레이크 마찰재료의 사용이 금지됨에 따라 K₂Oㆍ6TiO₂ whisker는 이의 대체 섬유로서 주목을 받고 있다. 이러한 K₂Oㆍ6TiO₂ whisker의 합성방법으로는 TiO₂와 K₂CO₃의 화학양론적 조성의 혼합들을 설정온도에서 소성(calcination method)시키는 방법을 비롯하여 응용법(melting method), 수열법(hydrothermal method), 융제법(flux) 및 KDC법(kneading-drying-calcination method) 등의 방법이 있다. 그러나 수열법의 경우 양질의 whisker를 얻을 수 있으나 고압합성 이므로 위험하고 가격이 비싼 결점이 있으며 공업상 제조에 필요한 조건이 복잡하고 연속조작이 어려워 비현실적인 방법이다. 또한 서냉소성법의 경우 공정이 단순하며 공업화가 쉬우나 비교적 장섬유가 얻어지게 된다. 따라서 본 연구에서는 융제법을 이용하여 K₂Oㆍ6TiO₂ whisker를 합성하였으며. 과거에 용제로 사용된 KC1-KF계. K₂O-Na₂O-B₂O₃계 등의 높은 volatility와 viscosity 그리고 낮은 solubility에 대한 문제점을 개선하기 위해 K₂WO₄를 flux로 선정하여 K₂Oㆍ6TiO₂ whisker를 합성하였다.

灌漑用水路의 水路損失率 算定에 관한 硏究

李基春,具滋雄,金在英,李宰泳,徐元明 전북대학교 농업과학기술연구소 1982 農大論文集 Vol.13 No.-

This study was carried out in order to estimate water losses in irrigation canals, which may be used to evaluate the water requirement for irrigation projects. The conveyance losses were measured by the inflow-outflow method, the seepage were measured by the ponding method, and the operation losses in the course of irrigation were calculated by comparing the two kinds of losses. The results obtained in this experiment were as follows : Conveyance losses per unit area of wetted perimeter per second by the main irrigation canal, the secondary irrigation canal and the tributary irrigation, canal, were 1.399x10-5m3/m3/sec, 5.154x10-5m3/m3/sec, and 2.670×10-5m3/m3/sec respectively in the Goong-sa area. And they were 1.934x10-5m3/m3/sec, 2.149x10-5m3/m3/sec, and 4.558x10-6m3/m3/sec respectively in the Seong-dug area. Seepage losses per unit area of wetted perimeter per second by the secondary irrigation canal and the tributary irrigation canal, were 2.180×10-6m3/m3/sec and 2.168×10-6m3/m3/sec in the Goons-sa area. 1.150x10-6m3/m3/sec and 1.084x10-6m3 /m3/sec in the Seong-dug area respectively. Operation losses per unit area of wetted perimeter per second by the secondary irrigation canal and the tributary irrigation canal, were 4.936×10-5m3/m3/sec and 2.453×10-5m3/m3/sec in the Goong-sa area, 2.034×10-5m3/m3/sec and 4.450×10-5m3/m3 /sec in the Seong-dug area respectively. Conveyance, seepage and operation losses in the Goong-sa area were 6.7%, 94.6%, and 14.0% more than those in the Seong-dug area. Operation losses amount to about 17 times as much as seepage losses in the Goons-sa area and about 29 times in the Seong-dug area .The seepage losses depend much on the soil texture. ranging from 7.437×10-7m3/m3/sec to 2.430x10-6 m3/m3/sec. Water loss rates in the main irrigation canal, the secondary irrigation canal and the tributary irrigation canal, were estimated as 8.49%. 37.27%, and 9.8l%, respectively in the Goong-sa area. And they were estimated as 15.10%, 32.67% and 13.73% respectively in the Seong-dug area.

2단계 급속동결 및 초자화 동결한 토끼상실배의 체외생존성에 관한 연구

정구민,이창규,임경순,김수헌 서울대학교농과대학농업개발연구소 1990 서울대농학연구지 Vol.15 No.1

본 시험은 수정란 급속동결보존기술의 개발을 위한 기초자료를 얻기 위하여 2단계 급속동결 및 초자화동결이 토끼 상실배의 체외발생등에 미치는 영향을 검토하고자 실시하였으며, 얻어진 결과는 다음과 같다. 1. 토끼 상실배를 1.5, 2.0, 2.5 및 3.0 M glycerol과 0.5 M sucrose가 포함된 동결액에 실온에서 10분간 노출후 -30℃에서 30∼40분간 정치하여 급속동결하였을 때 발생율은 각각 36.4, 83.3, 92.3 및 84.2%로 2.5 M glycerol에서 가장 높았다. 2. 토끼 상실배를 1.5, 2.0, 2.5 및 3.0 M 1,2-propanediol과 0.5 M sucrose가 포함된 동결액에 실온에서 10분간 노출 후 -30℃에서 30∼40분간 정치하여 급속동결하였을 때 발생율은 각각 26.6, 55.6, 65.0 및 52.9%로 2.5 M 1,2-propanediol에서 가장 높았으나, glycerol을 사용했을 때 보다 낮았다. 3. 토끼 상실배를 2.5, 3.0 및 3.5 M glycerol과 0.5 M trehalose가 포함된 동결액에 실온에서 10분간 노출후 액체질소에 침지하여 초급속동결한 결과 회수율은 각각 87.5, 92.5 및 92.5%, 형태적으로 정상인 수정란의 비율은 각각 37.5, 55.5 및 60.0%, 그리고 발생율은 각각 13.3, 36.4 및 37.5%로 3.5 M glycerol에서 가장 높았으나 초자화동결법보다 현저하게 낮았다. 4. 토끼 상실배를 25% glycerol과 25% 1,2-propanediol을 함유한 동결액에 실온에서 10분간 노출후 초자화동결했을 때 발생율은 75.0%로 실온에서 형평한 후 초자화동결이 가능하였다. This experiment was carried out to investigate on in vitro development of rabbit monla frozen by 2-step feezing and vitrification. The results obtained from this experiment are as follows; 1. When rabbit morula in m-PBS containing 1.5, 2.0, 2.5 or 3.0 M glyceral and 0.5 M sucrose for 10 min at room temperature were cooled at -30℃ for 30 to 40 min and plunged into liquid nitrogen, the proportion of embryo developed to expanded blastoyst was 36.4, 83.3, 92.3 and 84.2%, respectively. Glycerol 2.5 M showed higher survival than others. 2. When rabbit morula in m-PBS containing 1.5, 2.0, 2.5 or 3.0 M 1, 2-propanediol and 0.5 M sucrose for 10 min at room temperature were cooled at -30℃ for 30 to 40 min and plunged into liquid nitrogen, the proportion of embrye developed to expanded blastocyst was 26.6, 55.6, 65.0 and 52.9%, respectively. 1, 2-propanediol was less effective than glycerol. 3. When rabbit morula in m-PBS containing 2.5, 3.0 or 3.5 M glycerol and 0.5 M trehalose for 10 min at room temperature were plunged into liquid nitrogen and thawed rapidly, the recovery rate of embryo was 87.5, 92.5 and 92.5%, the proportion of morphologically normal embryo was 37.5, 55.5 and 60.0%, and the proportion of embryo developed to expanded blastocyst was 13.3. 36.4 and 37.5%, respectively. The proportion of embryo developed to expanded blastocyst was higher in vitrification than in plunging into liquid nitrogen. 4. When rabbit morula were frozen by vitrification in m-PBS containing 25% glycerol. 25% 1, 2-propanediol, the proportion of embryo developed to expanded blastocyst was 75.0%, the result suggested that rabbit embryos could be frozen by vitrification after equilibration at room temperature.

Supplemented vaccination with tandem repeat M2e virus-like particles enhances protection against homologous and heterologous HPAI H5 viruses in chickens

Song, B.M.,Kang, H.M.,Lee, E.K.,Jung, S.C.,Kim, M.C.,Lee, Y.N.,Kang, S.M.,Lee, Y.J. Butterworths ; Elsevier Science Ltd 2016 Vaccine Vol.34 No.5

Highly pathogenic avian influenza (HPAI) H5 viruses derived from A/Goose/Guangdong/1/96 have been continuously circulating globally, severely affecting the public health and poultry industries. The matrix 2 protein ectodomain (M2e) is considered a promising candidate for a universal cross-protective influenza vaccine that provides more effective control over HPAI H5 viruses harboring variant hemagglutinin (HA)-antigens. Here, we evaluated the protective efficacy of a tandem repeat construct of heterologous M2e presented on virus-like particles (M2e5x VLPs) either alone or as a supplement against HPAI H5 viruses in a chicken model. Chickens immunized with M2e5x VLPs alone induced M2e-specific antibodies but were not protected against HPAI H5. The homo- and cross-protective efficacy of M2e5x VLP-supplemented vaccination of chickens was also examined. Importantly, supplementation with M2e5x VLPs induced significantly higher levels of antibodies specific for M2e and different viruses as well as provided improved protection against homologous and heterologous HPAI H5 viruses. Considering the limited efficacy of inactivated vaccines, supplement vaccination with M2e5x VLPs may be an effective measure for preventing outbreaks of HPAI viruses that have the ability to constantly change their antigenic properties in poultry.

生體內 藥劑耐性 및 Plasmid 傳達에 關한 硏究

金鎬薰,李明遠,李英姬,金基湘,兪天權,吳明燉,李悌煥,李点揆,琴東吉,鄭泰華,李潤台 국립보건연구원 1989 국립보건원보 Vol.26 No.

Metabolic characterization of (1-(5-fluoropentyl)-1H-indol-3-yl)(4-methyl-1-naphthalenyl)-methanone (MAM-2201) using human liver microsomes and cDNA-overexpressed cytochrome P450 enzymes

Kong, T. Y.,Kim, J. H.,Choi, W. G.,Lee, J. Y.,Kim, H. S.,Kim, J. Y.,In, M. K.,Lee, H. S. Springer Science + Business Media 2017 Analytical and bioanalytical chemistry Vol.409 No.6

<P>MAM-2201 is a synthetic cannabinoid that is increasingly found in recreational drug abusers and cases of severe intoxication. Thus, characterization of the metabolic pathways of MAM-2201 is necessary to predict individual pharmacokinetics and toxicity differences, and to avoid toxic drug-drug interactions. Collectively, 19 phase 1 metabolites of MAM-2201 were identified using liquid chromatography-Orbitrap mass spectrometry following human liver microsomal incubations in the presence of NADPH: 7 hydroxy-MAM-2201 (M1-M7), 4 dihydroxy-MAM-2201 (M8-M11), dihydrodiol-MAM-2201 (M12), N-(5-hydroxypentyl)-MAM-2201 (M13), hydroxy-M13 (M14), N-dealkyl-MAM-2201 (M15), 2 hydroxy-M15 (M16, M17), MAM-2201 N-pentanoic acid (M18), and hydroxy-M18 (M19). On the basis of intrinsic clearance values in human liver microsomes, hydroxy-MAM-2201 (M1), N-(5-hydroxypentyl)-MAM-2201 (M13), and hydroxy-M13 (M14) were the major metabolites. Based on an enzyme kinetics study using human cDNA-expressed cytochrome P450 (CYP) enzymes and an immunoinhibition study using selective CYP antibodies in human liver microsomes, CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 enzymes were responsible for MAM-2201 metabolism. The CYP3A4 enzyme played a prominent role in MAM-2201 metabolism, and CYP1A2, CYP2B6, CYP2C8, and CYP2C9 enzymes played major roles in the formation of some metabolites. MAM-2201 is extensively metabolized by multiple CYP enzymes, indicating that MAM-2201 and its metabolites should be used as markers of MAM-2201 abuse and toxicity.</P>

Multistage symmetry breaking in the breathing pyrochlore latticeLi(Ga,In)Cr4O8

Lee, S.,Do, S.-H.,Lee, W.-J.,Choi, Y. S.,Lee, M.,Choi, E. S.,Reyes, A. P.,Kuhns, P. L.,Ozarowski, A.,Choi, K.-Y. American Physical Society 2016 Physical Review B Vol.93 No.17

<P>We present magnetic susceptibility, dielectric constant, high-frequency electron spin resonance, Li-7 nuclear magnetic resonance, and zero-field muon spin relaxation measurements of LiACr(4)O(8) (A = Ga, In), towards realizing a breathing pyrochlore lattice. Unlike the uniform pyrochlore ZnCr2O4 lattice, both the In and the Ga compounds feature two-stage symmetry breaking: a magnetostructural phase transition with subsequent antiferromagnetic ordering. We find a disparate symmetry breaking process between the In and the Ga compounds, having different degrees of bond alternation. Our data reveal that the Ga compound with moderate bond alternation shows the concomitant structural and magnetic transition at T-S = 15.2 K, followed by the magnetic ordering at T-m = 12.9 K. In contrast, the In compound with strong bond alternation undergoes a thermal crossover at T* approximate to 20.1 K from a tetramer singlet to a dimer singlet or a correlated paramagnet with a separate weak magnetostructural transition at T-S = 17.6 K and the second antiferromagnetic ordering at T-m = 13.7 K. This suggests that the magnetic phases and correlations of the breathing pyrochlore lattice can be determined from the competition between bond alternation and spin-lattice coupling, thus stabilizing long-range magnetic ordering against a nonmagnetic singlet.</P>

A novel chimeric promoter that is highly responsive to hypoxia and metals

Lee, J-Y,Lee, Y-S,Kim, J-M,Kim, K L,Lee, J-S,Jang, H-S,Shin, I-S,Suh, W,Jeon, E-S,Byun, J,Kim, D-K Nature Publishing Group 2006 Gene Therapy Vol.13 No.10

To develop a potent hypoxia-inducible promoter, we evaluated the usefulness of chimeric combinations of the (Egr-1)-binding site (EBS) from the Egr-1 gene, the metal-response element (MRE) from the metallothionein gene, and the hypoxia-response element (HRE) from the phosphoglycerate kinase 1 gene. In transient transfection assays, combining three copies of HRE (3 × HRE) with either EBS or MRE significantly increased hypoxia responsiveness. When a three-enhancer combination was tested, the EBS–MRE-3 × HRE (E–M–H) gave a hypoxia induction ratio of 69. The expression induced from E–M–H-pGL3 was 2.4-fold higher than that induced from H-pGL3 and even surpassed the expression from a human cytomegalovirus promoter-driven vector. The high inducibility of E–M–H was confirmed by validation studies in different cells and by expressing other cDNAs. Gel shift assays together with functional overexpression studies suggested that increased levels of hypoxia-inducible factor 1α, metal transcription factor-1 and Egr-1 may be associated with the high inducibility of the E–M–H chimeric promoter. E–M–H was also induced by hypoxia mimetics such as Co<SUP>2+</SUP> and deferoxamine (DFX) and by hydrogen peroxide. Gene expression from the E–M–H was reversible as shown by the reduced expression of the transgene upon removal of inducers such as hypoxia and DFX. In vivo evaluation of the E–M–H in ischemic muscle revealed that erythropoietin secretion and luciferase and LacZ expression were significantly higher in the E–M–H group than in a control or H group. With its high induction capacity and versatile means of modulation, this novel chimeric promoter should find wide application in the treatment of ischemic diseases and cancer.Gene Therapy (2006) 13, 857–868. doi:10.1038/sj.gt.3302728; published online 9 February 2006

Fe-Cu-M-(Si, B) (M = V, Nb, Mo, Ta, W) 합금의 연자기특성 (軟磁氣特性)

강일구,김희중,노태환,이명복,피우갑 대한금속재료학회(대한금속학회) 1990 대한금속·재료학회지 Vol.28 No.4

Dependence of the effective permeability on annealing and the annealing-induced structural change for amorphous Fe_(73.5)Cu₁M₃Si_(13.5)B_9(M=V, Nb, Mo, Ta or W)and Fe_(73.5)Cu₁Nb₃(Si_xB_(1-x))_(22.5)(x=0∼0.8) alloys were investigated. Crystalline Fe_(73.5)Cu₁M₃Si_(13.5)B_9(M=V, Nb, Mo, W)alloys with α-Fe phase which was obtained by annealing at above T_x showed higher effective permeability than with amorphous phase, and the increase in permeability upon crystallization was large in the order of V$lt;W$lt;Mo$lt;Nb. For amorphous Fe_(73.5)Cu₁Nb₃(Si_xB_(1-x))_(22.5) alloys in the composition range from x=0.5 to 0.8, soft magnetic property was improved by crystallization. Moreover, in that composition range, the effective permeability increased with the Si content(x). Superior soft magnetic property of the high-Si alloys was attributed to both the small magnetocrystalline anisotropy and the low magnetostriction. The effective permeabilities measured at 1㎑ and 5 m0e for crystalline Fe-Cu-Mo-Si-B and Fe-Cu-Nb-Si-B(0.5≤x≤0.8) alloys were about 1∼2 × 10⁴, and it was comparable to that of the zero-magnetostriction Co-based amorphous alloys.

Runx3 is required for the differentiation of lung epithelial cells and suppression of lung cancer

Lee, K-S,Lee, Y-S,Lee, J-M,Ito, K,Cinghu, S,Kim, J-H,Jang, J-W,Li, Y-H,Goh, Y-M,Chi, X-Z,Wee, H,Lee, H-W,Hosoya, A,Chung, J-H,Jang, J-J,Kundu, J K,Surh, Y-J,Kim, W-J,Ito, Y,Jung, H-S,Bae, S-C Macmillan Publishers Limited 2010 Oncogene Vol.29 No.23

Human lung adenocarcinoma, the most prevalent form of lung cancer, is characterized by many molecular abnormalities. K-ras mutations are associated with the initiation of lung adenocarcinomas, but K-ras-independent mechanisms may also initiate lung tumors. Here, we find that the runt-related transcription factor Runx3 is essential for normal murine lung development and is a tumor suppressor that prevents lung adenocarcinoma. Runx3−/− mice, which die soon after birth, exhibit alveolar hyperplasia. Importantly, Runx3−/− bronchioli exhibit impaired differentiation, as evidenced by the accumulation of epithelial cells containing specific markers for both alveolar (that is SP-B) and bronchiolar (that is CC10) lineages. Runx3−/− epithelial cells also express Bmi1, which supports self-renewal of stem cells. Lung adenomas spontaneously develop in aging Runx3+/− mice (∼18 months after birth) and invariably exhibit reduced levels of Runx3. As K-ras mutations are very rare in these adenomas, Runx3+/− mice provide an animal model for lung tumorigenesis that recapitulates the preneoplastic stage of human lung adenocarcinoma development, which is independent of K-Ras mutation. We conclude that Runx3 is essential for lung epithelial cell differentiation, and that downregulation of Runx3 is causally linked to the preneoplastic stage of lung adenocarcinoma.