Projections of high resolution climate changes for South Korea using multiple-regional climate models based on four RCP scenarios. Part 1: surface air temperature

Suh, M. S.,Oh, S. G.,Lee, Y. S.,Ahn, J. B.,Cha, D. H.,Lee, D. K.,Hong, S. Y.,Min, S. K.,Park, S. C.,Kang, H. S. SPRINGER SCIENCE AND BUSINESS MEDIA 2016 Asia-Pacific Journal of Atmospheric Sciences Vol.52 No.2

<P>We projected surface air temperature changes over South Korea during the mid (2026-2050) and late (2076-2100) 21st century against the current climate (1981-2005) using the simulation results from five regional climate models (RCMs) driven by Hadley Centre Global Environmental Model, version 2, coupled with the Atmosphere- Ocean (HadGEM2-AO), and two ensemble methods (equal weighted averaging, weighted averaging based on Taylor's skill score) under four Representative Concentration Pathways (RCP) scenarios. In general, the five RCM ensembles captured the spatial and seasonal variations, and probability distribution of temperature over South Korea reasonably compared to observation. They particularly showed a good performance in simulating annual temperature range compared to HadGEM2-AO. In future simulation, the temperature over South Korea will increase significantly for all scenarios and seasons. Stronger warming trends are projected in the late 21st century than in the mid-21st century, in particular under RCP8.5. The five RCM ensembles projected that temperature changes for the mid/late 21st century relative to the current climate are +1.54A degrees C/+1.92A degrees C for RCP2.6, +1.68A degrees C/+2.91A degrees C for RCP4.5, +1.17A degrees C/+3.11A degrees C for RCP6.0, and +1.75A degrees C/+4.73A degrees C for RCP8.5. Compared to the temperature projection of HadGEM2-AO, the five RCM ensembles projected smaller increases in temperature for all RCP scenarios and seasons. The inter-RCM spread is proportional to the simulation period (i.e., larger in the late-21st than mid-21st century) and significantly greater (about four times) in winter than summer for all RCP scenarios. Therefore, the modeled predictions of temperature increases during the late 21st century, particularly for winter temperatures, should be used with caution.</P>

Mechanical properties of (W,Ti)C and (W,Ti)C-NiAl₃ cermet consolidated by the high-frequency induction-heating method

Kim, W.,Suh, C.Y.,Roh, K.M.,Cho, S.W.,Na, K.I.,Shon, I.J. Elsevier Sequoia 2013 Journal of alloys and compounds Vol.568 No.-

In the case of cemented (W,Ti)C, Co is added as a binder for the formation of composite structures. However, the high cost of Co and the low corrosion resistance of the (W,Ti)C-Co cermet have generated interest in recent years for alternative binder phases. In this study, NiAl<SUB>3</SUB> was used as a binder and consolidated by the high-frequency induction heated sintering (HFIHS) method. The densification of both monolithic (W,Ti)C and (W,Ti)C-NiAl<SUB>3</SUB> cermet was accomplished within 3min. Highly dense (W,Ti)C and (W,Ti)C-NiAl<SUB>3</SUB> with a relative density of upto 99% were obtained within 3min by HFIHS under a pressure of 80MPa. The method was found to enable not only the rapid densification but also the prohibition of grain growth preserving the nano-scale microstructure. The average grain sizes of the sintered (W,Ti)C and (W,Ti)C-NiAl<SUB>3</SUB> were lower than 100nm. The addition of NiAl<SUB>3</SUB> to (W,Ti)C enhanced the toughness at the expense of the slight decrease in hardness. The hardness of (W,Ti)C and (W,Ti)C-NiAl<SUB>3</SUB> was significantly higher than that of (W,Ti)C-Co or (W,Ti)C-Ni. The fracture toughness and hardness values of (W,Ti)C, (W,Ti)C-5vol.%NiAl<SUB>3</SUB>, and (W,Ti)C-10vol.%NiAl<SUB>3</SUB> consolidated by HFIHS with a pressure of 80MPa and a induced current were 7.6+/-0.4MPam<SUP>½</SUP> and 2850+/-35kg/mm<SUP>2</SUP>, 8.5+/-0.3MPam<SUP>½</SUP> and 2610+/-37kg/mm<SUP>2</SUP>, 9.7+/-0.5MPam<SUP>½</SUP> and 2520+/-26kg/mm<SUP>2</SUP>, respectively.

c-Jun N-terminal kinase has a pivotal role in the maintenance of self-renewal and tumorigenicity in glioma stem-like cells

Yoon, C-H,Kim, M-J,Kim, R-K,Lim, E-J,Choi, K-S,An, S,Hwang, S-G,Kang, S-G,Suh, Y,Park, M-J,Lee, S-J Macmillan Publishers Limited 2012 Oncogene Vol.31 No.44

Uncovering the mechanisms that govern the maintenance of stem-like cancer cells is critical for developing therapeutic strategies for targeting these cells. Constitutive activation of c-Jun N-terminal kinase (JNK) has been reported in gliomas and correlates with histological grade. Here, we found that JNK signaling is crucial for the maintenance of ‘stemness’ in glioma cells. Sphere-cultured glioma cells showed more phosphorylation of JNK compared with serum-containing monolayer cultures. Importantly, blockade of JNK signaling with SP600125 or small interfering RNAs targeting JNK1 or JNK2 significantly reduced the CD133<SUP>+</SUP>/Nestin<SUP>+</SUP> population and suppressed sphere formation, colony formation in soft agar, and expression of stem cell markers in sphere-cultured glioma cells. Intriguingly, sphere-cultured glioma cells exhibited enhanced expression of Notch-2, but not Notch-1, -3 or -4, and JNK inhibition almost completely abrogated this increase. Blocking the phosphoinoside 3-kinase (PI3K)/Akt pathway with LY294002 or si-Akt also suppressed the self-renewal of sphere-cultured glioma cells. PI3K, but not Akt, had a role as an upstream kinase in JNK1/2 activation. In addition, treatment with si-JNK greatly increased etoposide- and ionizing radiation (IR)-induced cell death in glioma spheres. Consistent with glioma cell lines, glioma stem-like cells isolated from primary patient glioma cells also had a higher activity of JNK and Notch-2 expression. Importantly, inhibition of JNK2 led to a decrease of Notch-2 expression and suppressed the CD133<SUP>+</SUP>/Nestin<SUP>+</SUP> cell population in patient-derived primary glioma cells. Finally, downregulation of JNK2 almost completely suppressed intracranial tumor formation by glioma cells in nude mice. Taken together, these data demonstrate that JNK signaling is crucial for the maintenance of self-renewal and tumorigenicity of glioma stem-like cells and drug/IR resistance, and can be considered a promising target for eliminating stem-like cancer cells in gliomas.

약물중독의 경과와 최신요법

서병태,안창근,최근춘,김문호 中央醫學社 1971 中央醫學 Vol.21 No.6

Drug intoxication with coma patients of I.C.U in N.M.C for 6 years from April, 1965 to Oct, 1971 were reviewed. It was seen that barbiturate poisoning ,was the most common one and the parathion intoxications were not a little. The other causes of acute poisoning was seen such as rodenticide, acid alkali, meprobamate, etcetra. Meticulous treatment with respirator and prognostic problems related to death rate were discussed.

Effects of High-energy Ni-ion Irradiation in the InAlGaN/GaN Heterostructure

M.Senthil Kumar,Y.S. Lee,S.J. Chung,C.-H. Hong,E.-K. Suh 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.2

We report the effects of high-energy Ni-ion irradiation on the properties of the InAlGaN/GaN heterostructure grown on c-plane sapphire substrates by using a low-pressure metal organic chemical vapor deposition system. The heterostructure was irradiated with 100 MeV Ni ions for a fluence of 5 × 1012 cm−2 at room temperature. The X-ray rocking curve (0002) full width at half maximum (FWHM) value of the as-grown InAlGaN layer was measured to be 250 arcsec and was not affected by Ni-ion irradiation. However, the PL peak intensity of the heterostructure was completely quenched after ion irradiation, and its electrical properties turned to be highly insulating due to irradiation-induced defects. These results indicate that optical and electrical isolation is feasible in InAlGaN/GaN devices without damaging the crystalline quality by using the Ni-ion irradiation. The thermal annealing process could partly recover the optical and electrical properties of the heterostructure whereas, the junction properties of Schottky contacts fabricated on InAlGaN layer could not be restored. We report the effects of high-energy Ni-ion irradiation on the properties of the InAlGaN/GaN heterostructure grown on c-plane sapphire substrates by using a low-pressure metal organic chemical vapor deposition system. The heterostructure was irradiated with 100 MeV Ni ions for a fluence of 5 × 1012 cm−2 at room temperature. The X-ray rocking curve (0002) full width at half maximum (FWHM) value of the as-grown InAlGaN layer was measured to be 250 arcsec and was not affected by Ni-ion irradiation. However, the PL peak intensity of the heterostructure was completely quenched after ion irradiation, and its electrical properties turned to be highly insulating due to irradiation-induced defects. These results indicate that optical and electrical isolation is feasible in InAlGaN/GaN devices without damaging the crystalline quality by using the Ni-ion irradiation. The thermal annealing process could partly recover the optical and electrical properties of the heterostructure whereas, the junction properties of Schottky contacts fabricated on InAlGaN layer could not be restored.

High Epidural Block Anesthesia가 호흡기능에 미치는 영향

서병태,안창근,최근춘,김문호 中央醫學社 1971 中央醫學 Vol.21 No.6

Certain aspects of respiratory function and muscle power of hands were studied before and after the induction of high and broad epidural block anesthesia with 30m1. of 1% lidocaine in patients with normal respiratory systems. 1 The changes in vital capacity and maximum breathing capacity after the anesthesia were observed somewhat great, but there were no important changes in arterial blood PH, Pa C02 and standard bicarbonate. The muscle power of hands grasping after the anesthesia was observed and there was greater degree of weakness in hand grasping power after the anesthesia. It is concluded that no important degree of respiratory impairment during the resting state after the anesthesia. Rather important degree of muscle relaxation in the chest, diaphragm, abdomen and upper exrtemities resulted in after the high epidural block anesthesia, even with the use of lower concentration of lidocaine as 1% was discussed.

Novel signaling axis for ROS generation during K-Ras-induced cellular transformation

Park, M-T,Kim, M-J,Suh, Y,Kim, R-K,Kim, H,Lim, E-J,Yoo, K-C,Lee, G-H,Kim, Y-H,Hwang, S-G,Yi, J-M,Lee, S-J Macmillan Publishers Limited 2014 CELL DEATH AND DIFFERENTIATION Vol.21 No.8

Reactive oxygen species (ROS) are well known to be involved in oncogene-mediated cellular transformation. However, the regulatory mechanisms underlying ROS generation in oncogene-transformed cells are unclear. In the present study, we found that oncogenic K-Ras induces ROS generation through activation of NADPH oxidase 1 (NOX1), which is a critical regulator for the K-Ras-induced cellular transformation. NOX1 was activated by K-Ras-dependent translocation of p47<SUP>phox</SUP>, a subunit of NOX1 to plasma membrane. Of note, PKCδ, when it was activated by PDPK1, directly bound to the SH3-N domain of p47<SUP>phox</SUP> and catalyzed the phosphorylation on Ser348 and Ser473 residues of p47<SUP>phox</SUP> C-terminal in a K-Ras-dependent manner, finally leading to its membrane translocation. Notably, oncogenic K-Ras activated all MAPKs (JNK, ERK and p38); however, only p38 was involved in p47<SUP>phox</SUP>-NOX1-dependent ROS generation and consequent transformation. Importantly, K-Ras-induced activation of p38 led to an activation of PDPK1, which then signals through PKCδ, p47<SUP>phox</SUP> and NOX1. In agreement with the mechanism, inhibition of p38, PDPK1, PKCδ, p47<SUP>phox</SUP> or NOX1 effectively blocked K-Ras-induced ROS generation, anchorage-independent colony formation and tumor formation. Taken together, our findings demonstrated that oncogenic K-Ras activates the signaling cascade p38/PDPK1/PKCδ/p47<SUP>phox</SUP>/NOX1 for ROS generation and consequent malignant cellular transformation.

Effect of barrier growth temperature on morphological evolution of green InGaN/GaN multi-quantum well heterostructures

Senthil Kumar, M,Park, J Y,Lee, Y S,Chung, S J,Hong, C-H,Suh, E-K Institute of Physics [etc.] 2007 Journal of Physics. D, Applied Physics Vol.40 No.17

<P>Surface morphology of green InGaN/GaN multi-quantum wells (MQWs) on a sapphire substrate with various high temperature grown GaN barriers has been evaluated. Keeping the InGaN well growth temperature constant at 740 °C, a series of MQWs were grown with GaN barrier temperatures varied up to 910 °C. GaN barriers grown below 800 °C lead to the generation of a high density of V-defects and inclusions embedded within V-defects as observed by atomic force microscopy. Scanning electron microscopy and cathodoluminescence (CL) studies revealed that the embedded inclusions are of two kinds: one of them appears as bright spots in CL mapping while the other appears as the surrounding region. Temperature ramping and subsequent interruption for GaN barrier growth suppresses both kinds of inclusion defects and also significantly reduces the V-defect density. An inclusion-free smooth surface is obtained for green emitting InGaN/GaN MQWs with the GaN barrier grown at 910 °C.</P>

Pulmonary TB and NTM lung disease: comparison of characteristics in patients with AFB smear-positive sputum.

Koh, W J,Yu, C M,Suh, G Y,Chung, M P,Kim, H,Kwon, O J,Lee, N Y,Chung, M J,Lee, K S The Union 2006 The international journal of tuberculosis and lung Vol.10 No.9

<P>OBJECTIVE: To compare the clinical and radiographic features of pulmonary tuberculosis (PTB) and non-tuberculous mycobacteria (NTM) lung disease in patients with acid-fast bacilli (AFB) positive sputum specimens. DESIGN: The initial clinical and radiographic features of 229 PTB patients were compared with those of 70 patients with NTM lung disease. The most commonly involved organisms in the NTM lung disease cases were Mycobacterium avium complex (n = 38, 54%) and M. abscessus (n = 26, 37%). RESULTS: Clinical and radiographic findings that were more common in patients with NTM lung disease than in PTB patients were: older age (P < 0.001), non-smoker (P < 0.001), history of previous TB treatment (P < 0.001), absence of pleural effusion (P = 0.017), involvement of middle and/or lower lung zones (P = 0.007), and bilateral disease (P = 0.005). Multivariate analysis showed that older age (> or = 40 years), non-smoker, previous TB treatment, absence of pleural effusion and involvement of middle and/or lower lung zones were significant independent predictors for NTM lung disease. CONCLUSIONS: There is considerable overlap in the clinical and radiographic appearances of PTB and NTM lung disease. The isolation and identification of causative organisms are mandatory for a correct diagnosis in patients with AFB-positive sputum specimens.</P>

Synthesis and biological evaluation of C-ring truncated deguelin derivatives as heat shock protein 90 (HSP90) inhibitors

Kim, H.S.,Hong, M.,Ann, J.,Yoon, S.,Nguyen, C.T.,Lee, S.C.,Lee, H.Y.,Suh, Y.G.,Seo, J.H.,Choi, H.,Kim, J.Y.,Kim, K.W.,Kim, J.,Kim, Y.M.,Park, S.J.,Park, H.J.,Lee, J. Elsevier/Pergamon 2016 Bioorganic & medicinal chemistry Vol.24 No.22

Based on the lead compound L-80 (compound 2), a potent heat shock protein 90 (HSP90) inhibitor, a series of C-ring truncated deguelin analogs were designed, synthesized and evaluated for Hypoxia Inducible Factor-1α (HIF-1α) inhibition as a primary screening method. Their structure-activity relationship was investigated in a systematic manner by varying the A/B ring, linker and D/E ring, respectively. Among the synthesized inhibitors, compound 5 exhibited potent HIF-1α inhibition in a dose-dependent manner and significant antitumor activity in human non-small cell lung carcinoma (H1299), with better activities than L-80. It also inhibited in vitro hypoxia-mediated angiogenic processes in human retinal microvascular endothelial cells (HRMEC). The docking study of 5 showed a similar binding mode as L-80: it occupied the C-terminal ATP-binding pocket of HSP90, indicating that the anticancer and antiangiogenic activities of 5 were derived from HIF-1α destabilization by inhibiting the C-terminal ATP-binding site of hHSP90.