Fabrication of ex situ processed MgB₂ wires using nano carbon doped powder

Lee, C.M.,Park, J.H.,Hwang, S.M.,Lim, J.H.,Joo, J.,Kang, W.N.,Kim, C.J. North-Holland 2009 Physica. C, Superconductivity Vol.469 No.15

We fabricated ex situ MgB<SUB>2</SUB> wires using C-doped MgB<SUB>2</SUB> powder as a precursor in order to improve the core density of the wires and their C doping content. The C-doped powder was prepared with Mg, B, and nano carbon (NC) powders by the in situ technique and then MgB<SUB>2-x</SUB>C<SUB>x</SUB> (x=0, 0.01, and 0.03) wires were fabricated by the ex situ technique using the powder-in-tube method. The phase formation, lattice change, and microstructure were characterized and correlated with the T<SUB>c</SUB> and J<SUB>c</SUB> variations. We observed that the ex situ wire had a higher core density than the in situ wire, however its morphology consisted of agglomerated particles, indicating that sintering and grain growth did not occur completely, even though the sintering was conducted at high temperature (1000<SUP>o</SUP>C). As the C content increased, T<SUB>c</SUB> decreased, while the decrease of J<SUB>c</SUB> with increasing magnetic field became smaller. The J<SUB>c</SUB> of MgB<SUB>1.97</SUB>C<SUB>0.03</SUB> wire made by the ex situ technique was 3.34kA/cm<SUP>2</SUP> at 6.6T and 5K which is comparable to that of the in situ wire (4.81kA/cm<SUP>2</SUP> at 6.6T and 5K).

Hepatoprotective effect of vitamin C on lithocholic acid-induced cholestatic liver injury in Gulo(-/-) mice

Yu, S.J.,Bae, S.,Kang, J.S.,Yoon, J.H.,Cho, E.J.,Lee, J.H.,Kim, Y.J.,Lee, W.J.,Kim, C.Y.,Lee, H.S. North-Holland ; Elsevier Science Ltd 2015 european journal of pharmacology Vol.762 No.-

<P>Prevention and restoration of hepatic fibrosis from chronic liver injury is essential for the treatment of patients with chronic liver diseases. Vitamin C is known to have hepatoprotective effects, but their underlying mechanisms are unclear, especially those associated with hepatic fibrosis. Here, we analyzed the impact of vitamin Con bile acid induced hepatocyte apoptosis in vitro and lithocholic acid (LCA) induced liver injury in vitamin C-insufficient Gulo(-/-) mice, which cannot synthesize vitamin C similarly to humans. When Huh BAT cells were treated with bile acid, apoptosis was induced by endoplasmic retiiculum stress related JNK activation but vitamin C attenuated bile acid induced hepatocyte apoprosis in vitro. In our in vivo experiments. LCA feeding increased plasma marker of cholestasis and resulted in more extensive liver damage and hepatic fibrosis by more prominent apoptotic cell death and recruiting more intrahepatic inflammatory CD11b(+) cells in the liver of vitamin C-insufficient Gulo(-/-) mice compared to wild type mice which have minimal hepatic fibrosis. However, when vitamin C was supplemented to vitamin C-insufficient Gulo(-/-) mice, hepatic fibrosis was significantly attenuated in the liver of vitamin C-sufficient Gulo(-/-) mice like in wild type mice and this hepatoprotective effect of vitamin C was thought to be associated with both decreased hepatic apoptosis and necrosis. These results suggested that vitamin C had hepatoprotective effect against cholestatic liver injury. (C) 2015 Elsevier B.V. All rights reserved.</P>

Investigation of lauric acid dopant as a novel carbon source in MgB₂ wire

Lee, C.M.,Lee, S.M.,Park, G.C.,Joo, J.,Lim, J.H.,Kang, W.N.,Yi, J.H.,Jun, B.H.,Kim, C.J. North-Holland 2010 Physica. C, Superconductivity Vol.470 No.20

We fabricated lauric acid (LA) doped MgB<SUB>2</SUB> wires and investigated the effects of the LA doping. For the fabrication of the LA-doped MgB<SUB>2</SUB> wires, B powder was mixed with LA at 0-5wt.% of the total amount of MgB<SUB>2</SUB> using an organic solvent, dried, and then the LA-treated B and Mg powders were mixed stoichiometrically. The powder mixture was loaded into an Fe tube and the assemblage was drawn and sintered at 900<SUP>o</SUP>C for 3h under an argon atmosphere. We observed that the LA doping induced the substitution of C for the B sites in MgB<SUB>2</SUB> and that the actual content of C increased monotonically with increasing LA doping level. The LA-doped MgB<SUB>2</SUB> wires exhibited a lower critical temperature (T<SUB>c</SUB>), but better critical current density (J<SUB>c</SUB>) behavior in a high magnetic field: the 5wt.% LA-doped sample had a J<SUB>c</SUB> value of 5.32x10<SUP>3</SUP>A/cm<SUP>2</SUP>, which was 2.17 times higher than that of the pristine sample (2.45x10<SUP>3</SUP>A/cm<SUP>2</SUP>) at 5K and 6T, suggesting that LA is an effective C dopant in MgB<SUB>2</SUB> for enhancing the high-field J<SUB>c</SUB> performance.

TmSR-C, scavenger receptor class C, plays a pivotal role in antifungal and antibacterial immunity in the coleopteran insect Tenebrio molitor

Kim, S.G.,Jo, Y.H.,Seong, J.H.,Park, K.B.,Noh, M.Y.,Cho, J.H.,Ko, H.J.,Kim, C.E.,Tindwa, H.,Patnaik, B.B.,Bang, I.S.,Lee, Y.S.,Han, Y.S. Pergamon Press ; Elsevier Science Ltd 2017 Insect biochemistry and molecular biology Vol.89 No.-

Scavenger receptors (SRs) constitute a family of membrane-bound receptors that bind to multiple ligands. The SR family of proteins is involved in removing cellular debris, oxidized low-density lipoproteins, and pathogens. Specifically, class C scavenger receptors (SR-C) have also been reported to be involved in phagocytosis of gram-positive and -negative bacteria in Drosophila and viruses in shrimp. However, reports are unavailable regarding the role of SR-C in antifungal immune mechanisms in insects. In this study, a full-length Tenebrio molitor SR-C (TmSR-C) sequence was obtained by 5'- and 3'-Rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). The TmSR-C full-length cDNA comprised 1671 bp with 5'- and 3'-untranslated regions of 23- and 107-bp, respectively. TmSR-C encodes a putative protein of 556 amino acid residues that is constitutively expressed in all tissues of late instar larvae and 2-day-old adults, with the highest transcript levels observed in hemocytes of larvae and adults. TmSR-C mRNA showed a 2.5-fold and 3-fold increase at 24 and 6 h after infection with Candida albicans and β-glucan, respectively. Immunoassay with TmSR-C polyclonal antibody showed induction of the putative protein in the cytosols of hemocytes at 3 h after inoculation of C. albicans. RNA interference (RNAi)-based gene silencing and phagocytosis assays were used to understand the role of TmSR-C in antifungal immunity. Silencing of TmSR-C transcripts reduced the survivability of late instar larvae at 2 days post-inoculation of C. albicans, Escherichia coli, or Staphylococcus aureus. Furthermore, in TmSR-C-silenced larvae, there was a decline in the rate of microorganism phagocytosis. Taken together, results of this study suggest that TmSR-C plays a pivotal role in phagocytosing not only fungi but also gram-negative and -positive bacteria in T. molitor.

정상인 및 당뇨병환자에서의 경구당부하시 혈중 Insulin과 C-Peptide의 변동

이명철,고창순,최성재,김응진,민헌기 대한핵의학회 1977 핵의학 분자영상 Vol.11 No.1

저자들은 정상인 및 당뇨병환자에서 insulin과 C-peptide의 변동양상의 의의를 관찰하고 또한 비만이 insulin 반응에 영향을 끼치는 것을 보고자 정상인 15명 (비비만형 10명, 비만형 5명), 중등도당뇨병환자 22례 (비비만형 13례, 비만형 9례) 및 중증당뇨병환자 9례, 총 46명을 대상으로 경구적 당부하시험을 시행하고 각 혈중 insulin과 C-peptide를 방사면역법으로 측정하여 다음과 같은 결과를 얻었기에 보고하는 바이다. 1) 10명의 비비만형정상인에서의 insulin치는 공복시 및 100 gm 경구당부하후 30, 60, 90, 120분에서 각각 15.7±3.4, 48.3±9.8, 4.4±6.7, 37.4±6.5 및 26.0±4.2uU/ml(Mean±S.E.)이고 C-peptide는 각각 1.9±0.3, 3.9±0.6, 6.3±0.6, 5.7±0.5 및 4.0±0.5 ng/ml로서 insulin가 C-peptide 평행한 반응을 보였고 insulin은 30분에서 최고치를 나타낸 반면 C-peptide는 60분에서 최고치를 보였다. 2) 비만형정상인 5례에서 insulin은 각각 38.9±12.3, 59.5±12.3, 59.2±17.1, 56.1±20.0 및 48.4±17.2uU/ml이고 C-peptide는 각각 5.5±0.4, 6.8±0.5, 7.9±0.8, 7.9±0.8 및 7.8±2.0ng/ml로서 비비만형에 비하여 반응이 현저히 증가함을 보였다. 3) 13례의 비비만형중등도당뇨병환자의 혈장내 insulin은 각각 27.1±4.9, 44.1±6.0, 37.3±6.6, 35.5±8.1 및 34.7±10.7uU/ml이고 C-peptide는 각각 2.7±0.4, 4.9±0.7, 6.5±0.5, 7.0±0.3 및 6.7±1.0ng/ml로서 비비만형정상군에 비하여 insulin 및 C-peptide의 차이는 없으나 지연되는 양상을 보였다. 4) 비비만형중등도당뇨병환자 9명에서의 insulin은 각각 22.1±7.9, 80.0±19.3, 108.0±27.0, 62.0±17.6 및 55.5±10.1 uU/ml이었으며 C-peptide는 5.2±0.4, 8.0±1.0, 10.4±1.6, 10.4±1.7 및 10.0±10ng/ml로서 insulin과 C-peptide 반응이 비비만형중둥도당뇨병환자군에 비해 각각 항진됨을 볼 수 있었다. 5) 중증당뇨병환자 9례에서의 혈중 insulin은 8.0±3.8, 12.1±3.5, 16.8±4.6, 19.6±5.2 및 15.0±5.0uU/ml이며 C-peptide는 1.6±0.3, 2.4±0.4, 4.1±0.6, 4.0±0.8 및 4.5±0.7ng/ml로서 insulin과 C-peptide가 각각 현저히 감소하였다. 이 각 당뇨병환자군에서의 총 insulin 및 C-peptide 면적, 그리고 insulinogenic index와 C-peptide index를 산출한 결과 당뇨병정도에 따른 유의한 차이를 관찰하였다. The present study was undertaken to evaluate the significance of the insulin and the C-peptide rseponse to oral glucose loads in normal and diabetic subjects and to establish the effects of the obesity. In this study, the authors have measured plasma insulin and C-peptide by means of radioimmunoassay in 10 nonobese normal, 5 obese normal, 13 nonobese moderate diabetic patients, 9 obese moderate diabetic patients and 9 severe diabetic patients. The results obtained were as follows; 1) In 10 nonobese normal subjects, the plasma insulin level at fasting state and at 30, 60, 90, and 120 min after oral glucose loads were 15.7±3.4, 48.3±9.8, 40.4±6.7, 37.4±6.5 and 26.0±4.2uU/ml(Mean±S.E.) and C-peptide were 1.9±0.3, 3.9±0.6, 6.3±0.6, 5.7±0.5 and 4.0±0.5ng/ml. The change of C-peptide was found to go almost parallel with that of insulin and the insulin value reaches to the highest level at 30 min whereas C-peptide reaches to its peak at 60min. 2) The plasma insulin level in 5 obese normal subjects were 38.5±12.3, 59.2±17.1, 56.1±20.0 and 48.4±17.2 uU/ml and the C-peptide were 5.5±0.4, 6.8±0.5, 7.9±0.8, 7.9±0.8 and 7.8±2.0ng/ml. The insulin response appeared to be greater than nonobese normal subjects. 3) In 13 nonobese moderate diabetic patients, the plasma insulin levels were 27.1±4.9, 44.1±6.0, 37.3±6.6, 35.5±8.1 and 34.7±10.7uU/ml and the C-peptide levels were 2.7±0.4, 4.9±0.7, 6.5±0.5, 7.0±0.3 and 6.7±1.0ng/ml. There was little significance compared to nonobese normal groups but delayed pattern is noted. 4) In 9 obese moderated diabetic patients, the plasma insulin levels were 22.1±7.9, 80.0±19.3, 108.0±27.0, 62.0±17.6 and 55.5±10.luU/ml and the C-peptide levels were 5.2±0.4, 8.0±1.0, 10.4±1.6, 10.4±1.7 and 10.1±1.0ng/ml and its response was also greater than that of nonobese moderate diabetic patients. 5) The plasma insulin concentrations in 9 severe diabetic subjects were 8.0±3.8, 12.1±3.5, 16.8±4.6, 19.6±5.2 and 15.0±5.0uU/ml and the C-peptide levels were 1.6±0.3, 2.4/ml and the insulin and C-peptide responses were markedly reduced in severe diabetic groups. 6) There were significant differences between each groups of patients on the magnitude of total insulin or C-peptide areas, the insulinogenic index and the C-peptide index. $quot;

Novel dentin phosphoprotein frameshift mutations in dentinogenesis imperfecta type II

Lee, K‐,E,Kang, H‐,Y,Lee, S‐,K,Yoo, S‐,H,Lee, J‐,C,Hwang, Y‐,H,Nam, KH,Kim, J‐,S,Park, J‐,C,Kim, J‐,W Blackwell Publishing Ltd 2011 Clinical genetics Vol.79 No.4

<P>Lee K‐E, Kang H‐Y, Lee S‐K, Yoo S‐H, Lee J‐C, Hwang Y‐H, Nam KH, Kim J‐S, Park J‐C, Kim J‐W. Novel dentin phosphoprotein frameshift mutations in dentinogenesis imperfecta type II.</P><P>The dentin sialophosphoprotein (<I>DSPP</I>) gene encodes the most abundant non‐collagenous protein in tooth dentin and DSPP protein is cleaved into several segments including the highly phosphorylated dentin phosphoprotein (DPP). Mutations in the <I>DSPP</I> gene have been solely related to non‐syndromic form of hereditary dentin defects. We recruited three Korean families with dentinogenesis imperfecta (DGI) type II and sequenced the exons and exon–intron boundaries of the <I>DSPP</I> gene based on the candidate gene approach. Direct sequencing of PCR products and allele‐specific cloning of the highly repetitive exon 5 revealed novel single base pair (bp) deletional mutations (c.2688delT and c.3560delG) introducing hydrophobic amino acids in the hydrophilic repeat domain of the DPP coding region. All affected members of the three families showed exceptionally rapid pulp chambers obliteration, even before tooth eruption. Individuals with the c.3560delG mutation showed only mild, yellowish tooth discoloration, in contrast to the affected individuals from two families with c.2688delT mutation. We believe that these results will help us to understand the molecular pathogenesis of DGI type II as well as the normal process of dentin biomineralization.</P>

Somatic Mutations in TSC1 and TSC2 Cause Focal Cortical Dysplasia

Lim, J.S.,Gopalappa, R.,Kim, S.H.,Ramakrishna, S.,Lee, M.,Kim, W.i.,Kim, J.,Park, S.M.,Lee, J.,Oh, J.H.,Kim, H.D.,Park, C.H.,Lee, J.S.,Kim, S.,Kim, D.S.,Han, J.M.,Kang, H.C.,Kim, H.(.,Lee, J.H. University of Chicago Press [etc.] 2017 American journal of human genetics Vol.100 No.3

<P>Focal cortical dysplasia (FCD) is a major cause of the sporadic form of intractable focal epilepsies that require surgical treatment. It has recently been reported that brain somatic mutations in MTOR account for 15%-25% of FCD type II (FCDII), characterized by cortical dyslamination and dysmorphic neurons. However, the genetic etiologies of FCDII-affected individuals who lack the MTOR mutation remain unclear. Here, we performed deep hybrid capture and amplicon sequencing (read depth of 100 x-20,012 x) of five important mTOR pathway genes-PIK3CA, PIK3R2, AKT3, TSC1, and TSC2-by using paired brain and saliva samples from 40 FCDII individuals negative for MTOR mutations. We found that 5 of 40 individuals (12.5%) had brain somatic mutations in TSC1 (c.64C>T [p.Arg22Trp] and c.610C>T [p.Arg204Cys]) and TSC2 (c.4639G>A [p.Va11547I1e]), and these results were reproducible on two different sequencing platforms. All identified mutations induced hyperactivation of the mTOR pathway by disrupting the formation or function of the TSC1TSC2 complex. Furthermore, in utero CRISPR-Cas9-mediated genome editing of Tsc1 or Tsc2 induced the development of spontaneous behavioral seizures, as well as cytomegalic neurons and cortical dyslamination. These results show that brain somatic mutations in TSC1 and TSC2 cause FCD and that in utero application of the CRISPR-Cas9 system is useful for generating neurodevelopmental disease models of somatic mutations in the brain.</P>

Intramolecular energy flow and bond dissociation in iodoacetylene and iododiacetylene

Ree,J.,Shin,H. K,Lee,C. S.,Kim,Y.H. 國立昌原大學校 基礎科學硏究所 1994 基礎科學硏究所論文集 Vol.6 No.-

Intermolecular and intramolecular energy flow and subsequent bond dissociation in collinear collisions Ⅰ-C≡C-H+Ar and Ⅰ-C≡C-C≡C-H+Ar have been studied by classical trajectory techniques over the collision energy range of 0 to 10 eV. When the molecule is initially in the ground state, the overall energy transfer in Ⅰ-C≡C-H+Ar is very small, but in Ⅰ-C≡C-C≡C-H+Ar it is large. The collisionally perturbed C-H bond stores a large amount of energy from translation for a brief period during the early stage of collision and transfers most of it to the inner region of the molecule, specifically to the low frequency C-I vibration. Thus the high-frequency vibration of the perturbed C-H bond during the collision plays a crucial role in determining the extent of intramolecular energy transfer and, in turn, C-I dissociation. But in nondissociative collisions, there is another series of the C-H vibration at the latter stage of collision. transferring energy back to translation. This study also considers collision-induced intramolecular energy flow in the molecule with an initially excited C-H bond. The relaxation of the low-lying C-H excitation is significantly weakened, thus becoming comparable to that of the triple bond, in which case the isolating effect of the adjacent C≡C bond is no longer important and intramolecular energy flow becomes efficient.

Improvement of high-field J_c of MgB₂ wires by polymethyl-methacrylate doping

Park, G.C.,Hwang, S.M.,Lee, C.M.,Choi, J.H.,Joo, J.,Lim, J.H.,Kang, W.N.,Kim, C.J. North-Holland 2010 Physica. C, Superconductivity Vol.470 No.suppl1

We applied polymethyl-methacrylate (PMMA) as a new doping material for MgB<SUB>2</SUB> and fabricated C-doped MgB<SUB>2</SUB> wires by in situ powder-in-tube (PIT) process. With increasing PMMA doping level, the transition temperature (T<SUB>c</SUB>) decreased and the MgO content increased, whereas the magnetic field dependence of the critical current density (J<SUB>c</SUB>) weakened. The MgB<SUB>2</SUB> wires doped with 3-10wt.% PMMA showed significantly higher J<SUB>c</SUB> by more than one order of magnitude than that of the undoped wire at 5K and 6.6T. These results confirmed the potential of PMMA as a promising material for the effective substitution of B by C in MgB<SUB>2</SUB>.

Holocene environmental change at the southern coast of Korea based on organic carbon isotope (δ¹³C) and C/S ratios

Lim, J.,Lee, J.Y.,Kim, J.C.,Hong, S.S.,Yang, D.Y. Pergamon Press 2015 QUATERNARY INTERNATIONAL Vol.384 No.-

<P>To trace the environmental change that occurred at a coastal area during the Holocene, we performed radiocarbon dating and geochemical analyses using sedimentary cores recovered from the Beolgyo tidal flats on the south coast of Korea. The delta C-13 values of total organic carbon (TOC), which represent relative inputs of terrestrial (or freshwater) and marine organic sources, revealed a long-term increasing trend from -27.5 to -21.7 parts per thousand during the period between 10,000 and 3000 cal BP, suggesting an evolutionary series of fluvial-dominant to marine-dominant environments, coupled with weakened summer monsoon intensity. From 3000 cal BP to the present, the delta C-13(TOC) decreased gradually from -21.7 to -24 parts per thousand, indicating enhancement of freshwater input during this time. The observed long-term environmental change was divided into six stages based on the averages of the total sulfur content (TS%) and the organic carbon to sulfur ratio (C/S), proxies for paleosalinity. On multi-centennial to millennial timescales, higher C/S ratios and lower TS% were linked to higher delta C-13(TOC) values, indicating strong freshwater input at Stage 2 (similar to 8300-7400 cal BP), Stage 4 (similar to 4500-3300 cal BP), and Stage 6 (similar to 1100 cal BP to present). Strong freshwater discharge events synchronously occurred at 4300 cal BP and 3600 cal BP along the south coast of Korea. Further testing should be carried out in other East Asian coastal areas. This study suggests that sedimentary delta C-13(TOC) values and C/S ratios can be used in Asian coastal regions to trace past freshwater input events and summer monsoon intensity during relatively stable sea level periods (e.g., the middle to late Holocene). (C) 2015 Elsevier Ltd and INQUA. All rights reserved.</P>