Defect reduction of SiN_x embedded m-plane GaN grown by hydride vapor phase epitaxy

Woo, S.,Kim, M.,So, B.,Yoo, G.,Jang, J.,Lee, K.,Nam, O. North-Holland Pub. Co 2014 Journal of crystal growth Vol.407 No.-

Nonpolar (10-10) m-plane GaN has been grown on m-plane sapphire substrates by hydride vapor phase epitaxy (HVPE). We studied the defect reduction of m-GaN with embedded SiN<SUB>x</SUB> interlayers deposited by ex-situ metal organic chemical vapor deposition (MOCVD). The full-width at half-maximum values of the X-ray rocking curves for m-GaN with embedded SiN<SUB>x</SUB> along [11-20]<SUB>GaN</SUB> and [0001]<SUB>GaN</SUB> were reduced to 528 and 1427arcs, respectively, as compared with the respective values of 947 and 3170arcs, of m-GaN without SiN<SUB>x</SUB>. Cross-section transmission electron microscopy revealed that the basal stacking fault density was decreased by approximately one order to 5x10<SUP>4</SUP>cm<SUP>-1</SUP> due to the defect blocking of the embedded SiN<SUB>x</SUB>. As a result, the near band edge emission intensities of the room-temperature and low-temperature photoluminescence showed approximately two-fold and four-fold improvement, respectively.

Melatonin enhances arsenic trioxide-induced cell death via sustained upregulation of Redd1 expression in breast cancer cells

Yun, S.M.,Woo, S.H.,Oh, S.T.,Hong, S.E.,Choe, T.B.,Ye, S.K.,Kim, E.K.,Seong, M.K.,Kim, H.A.,Noh, W.C.,Lee, J.K.,Jin, H.O.,Lee, Y.H.,Park, I.C. North-Holland 2016 Molecular and cellular endocrinology Vol.422 No.-

Melatonin is implicated in various physiological functions, including anticancer activity. However, the mechanism(s) of its anticancer activity is not well understood. In the present study, we investigated the combined effects of melatonin and arsenic trioxide (ATO) on cell death in human breast cancer cells. Melatonin enhanced the ATO-induced apoptotic cell death via changes in the protein levels of Survivin, Bcl-2, and Bax, thus affecting cytochrome c release from the mitochondria to the cytosol. Interestingly, we found that the cell death induced by co-treatment with melatonin and ATO was mediated by sustained upregulation of Redd1, which was associated with increased production of reactive oxygen species (ROS). Combined treatment with melatonin and ATO induced the phosphorylation of JNK and p38 MAP kinase downstream from Redd1 expression. Rapamycin and S6K1 siRNA enhanced, while activation of mTORC1 by transfection with TSC2 siRNA suppressed the cell death induced by melatonin and ATO treatment. Taken together, our findings suggest that melatonin enhances ATO-induced apoptotic cell death via sustained upregulation of Redd1 expression and inhibition of mTORC1 upstream of the activation of the p38/JNK pathways in human breast cancer cells.

Highly sensitive wavelength-dependent nonaqueous capillary electrophoresis for simultaneous screening of various synthetic organic dyes

Park, M.,Bahng, S.H.,Woo, N.,Kang, S.H. Pergamon Press ; Elsevier Science Ltd 2016 Talanta Vol.152 No.-

<P>A novel multi-wavelength nonaqueous capillary electrophoresis (MW-NACE) technique based on wave-length-dependent laser-induced fluorescence (LIF) detection was investigated for the simultaneous screening of various synthetic organic dyes. Multi-wavelength excitation light sources were utilized to excite different organic dyes [e.g., 543 nm for crystal violet (CV), methyl violet B (MVB), methyl violet B base (MBB), rhodamine 6G (R6G), and rhodamine B base (RBB); 635 nm for nile blue A (NBA) and methylene blue (MB)] simultaneously. Using a nonaqueous buffer system composed of 15 mM sodium borate and 835 mM acetic acid in 100% ethanol (pH=5.4), all dyes were analyzed within 15 mM with excellent resolution (R >= 4.0) under an electric field of 500 V/cm. Calibration curves showed excellent linearity with square of correlation coefficients (r(2)) greater than 0.9908 over wide dynamic ranges of 0.4-50 mu M for CV, 0.8-50 mu M for MVB, 1.5-50 mu M for MBB, 0.08-5 nM for R6G, 0.06-10 mu M for MB, 0.02-10 mu M for NBA, and 0.13-10 pM for RBB. The detection limits (S/N=3) of 40 fM to 0.5 mu M were 10-200,000 times lower than those of previous detection methods. While adjacent peaks were not well distinguished with baseline separation in a single capillary, the devised technique was faster and more sensitive than conventional aqueous and nonaqueous CE approaches, thereby enabling the quantitative analysis of various dyes based on wavelength-dependent fluorescence detection with different excitation wavelengths. (C) 2016 Elsevier B.V. All rights reserved.</P>

Moracin M inhibits airway inflammation by interrupting the JNK/c-Jun and NF-κB pathways in vitro and in vivo

Lee, J.H.,Ko, H.J.,Woo, E.R.,Lee, S.K.,Moon, B.S.,Lee, C.W.,Mandava, S.,Samala, M.,Lee, J.,Kim, H.P. North-Holland ; Elsevier Science Ltd 2016 european journal of pharmacology Vol.783 No.-

<P>The therapeutic effectiveness of moracins as 2-arylbenzofuran derivatives against airway inflammation was examined. Moracin M, O, and R were isolated from the root barks of Morus alba, and they inhibited interleukin (IL)-6 production from IL-1 beta-treated lung epithelial cells (A549) at 101-00 mu M. Among them, moracin M showed the strongest inhibitory effect (IC50=8.1 mu M). Downregulation of IL-6 expression by moracin M was mediated by interrupting the c-Jun N-terminal kinase (JNK)/c-Jun pathway. Moracin derivatives inhibited inducible nitric oxide synthase (iNOS)-catalyzed NO production from lipopolysaccharide (LPS)-treated alveolar macrophages (MH-S) at 50-100 mu M. In particular, moracin M inhibited NO production by downregulating iNOS. When orally administered, moracin M (20-60mg/kg) showed comparable inhibitory action with dexamethasone (30mg/kg) against LPS-induced lung inflammation, acute lung injury, in mice with that of dexamethasone (30mg/kg). The action mechanism included interfering with the activation of nuclear transcription factor-kB in inflamed lungs. Therefore, it is concluded that moracin M inhibited airway inflammation in vitro and in vivo, and it has therapeutic potential for treating lung inflammatory disorders. (C) 2016 Elsevier B.V. All rights reserved.</P>

Butyric acid production from softwood hydrolysate by acetate-consuming Clostridium sp. S1 with high butyric acid yield and selectivity

Kim, M.,Kim, K.Y.,Lee, K.M.,Youn, S.H.,Lee, S.M.,Woo, H.M.,Oh, M.K.,Um, Y. Elsevier Applied Science 2016 Bioresource technology Vol.218 No.-

The aim of this work was to study the butyric acid production from softwood hydrolysate by acetate-consuming Clostridium sp. S1. Results showed that Clostridium sp. S1 produced butyric acid by simultaneously utilizing glucose and mannose in softwood hydrolysate and, more remarkably, it consumed acetic acid in hydrolysate. Clostridium sp. S1 utilized each of glucose, mannose, and xylose as well as mixed sugars simultaneously with partially repressed xylose utilization. When softwood (Japanese larch) hydrolysate containing glucose and mannose as the main sugars was used, Clostridium sp. S1 produced 21.17g/L butyric acid with the yield of 0.47g/g sugar and the selectivity of 1 (g butyric acid/g total acids) owing to the consumption of acetic acid in hydrolysate. The results demonstrate potential of Clostridium sp. S1 to produce butyric acid selectively and effectively from hydrolysate not only by utilizing mixed sugars simultaneously but also by converting acetic acid to butyric acid.

1987년 한국에서 발생한 렙토스피라병의 혈청역학적 조사

이증훈,박영수,이우곤,김석용,정선식,우준희,박성광,박경희,송영욱,김선영,기정일,최두혁,강성귀,김주완,최강원,김우열,최명식,최인학,장우현,윤성열 대한감염학회 1988 감염 Vol.20 No.3

Human leptospirosis was an unfamiliar disease in Korea until 1984 that outbreak of leptospirosis occurred among farmers and soldiers after field works for harvesting rice. During that time, Lee and Jo confirmed the first Korean cases of leptospirosis by serological test, isolation of causative agent and autopy findings. Afterward several outbreaks occurred also during autumn especially after flood in every years and some characterisitcs of leptospirosis in Korea such as clinical manifestations, serotypes and seroepidemiological features has been revealed by many investigators. Because of the major mode of transmission between rodents and human is by direct contact with leptospiral urine of rodents or contaminated soil by the urine, leptospirosis in Korea has been primarily a disease of person in occupations heavily exposed to contaminated soil or infected urine such as farmer, army and etc. Therefore it seems that leptospirosis is one of the main communicable diseases to be controlled urgently in Korea, for an agricultural people account for almost half of total Korean people. For clarifying the seroepidemiological patterns of human leptospirosis in Korea by sex, month region and main reacting serovars of L. interrogans among acute febrile disease occurred in 1987, 1,773 patient's sers with acute febrile episodes were tested by microagglutination test using 19 representative strains of leptospiral serogroup as antigen. All of those sera were collected from 10 collaborative clinics located in Kyunggi, Kangwon, Chungbuk, Chungnam, Chonbuk, Chonnam province and Seoul. The results wee summerized as follows. 1) Among 1,773 sera of patients with acute febrile episodes, 219 (12.4%) were seropositive to L. interrogans, 487(27.5%) to R. tsutsugamushi, 241(13.6%) to R.typhi and 160(90.0%) to Hantaan virus. 2) Among seropositives to L.interrogans, the male outnumbered the female, 65% and 35%. 3) For age distribution, 26.9% of seropositives to L.interrogans were fifties, 19.6% were forties, 9.1% were sixties, 5.9% were thirties and 4.1% were twenties. 4) Eighty three percent of seropositives had occurred between September and October in 1987 with a peak in September. 5) Main leptospiral serovars reactive to patient's sera were Icterohaemorrhagiae(54.3%), Canicola(31.0%), CH-48(13.2%), Tarassovi(0.9%)and Cynopteri(0.5%). 6) For regional distribution, 65.8% of seropositives to L.interrogans were residents from Chonbuk, 12.3% were Chonnam, 7.3% were Chungnam, 5.5% were Kyunggi and 1.4% were Kangwon.

Clinical and histopathological study of Charcot-Marie-Tooth neuropathy with a novel S90W mutation in BSCL2.

Choi, B-O,Park, M-H,Chung, K W,Woo, H-M,Koo, H,Chung, H-K,Choi, K-G,Park, K D,Lee, H J,Hyun, Y S,Koo, S K Oxford University Press 2013 Neurogenetics Vol.14 No.1

<P>The objective of the study was to investigate the disease-causing mutation in an autosomal dominant Charcot-Marie-Tooth disease type 2 family and examine the clinical and histopathological evaluation. We enrolled a family of Korean origin with axonal Charcot-Marie-Tooth disease neuropathy (FC305; 13 males, six females) and applied genome-wide linkage analysis. Whole exome sequencing was performed for two patients. In addition, sural nerve biopsies were obtained from two patients. Through whole exome sequencing, we identified an average of 20,336 coding variants from two patients. We also found evidence of linkage mapped to chromosome 11p11-11q13.3 (LOD score of 3.6). Among these variants in the linkage region, we detected a novel p.S90W mutation in the Berardinelli-Seip congenital lipodystrophy 2 (BSCL2) gene, after filtering 31 Korean control exomes. Our p.S90W patients had frequent sensory disturbances, pyramidal tract signs, and predominant right thenar muscle atrophy in comparison with reported p.S90L patients. The phenotypic spectra were wide and demonstrated intrafamilial variability. Two patients with different clinical features underwent sural nerve biopsies; the myelinated fiber densities were increased slightly in both patients, which differed from two previous case reports of BSCL2 mutations (p.S90L and p.N88S). This report expands the variability of the clinical spectrum associated with the BSCL2 gene and describes the first family with the p.S90W mutation.</P>

대학생 자녀를 둔 중년여성의 자아존중감, 자녀와의 관계, SNS 이용강도가 우울에 미치는 영향

우지원,김가은,김경미,남주희,박지인,범준희,이나경,조소연,조은경,최영윤,김석선,길민지 이화여자대학교 간호과학대학 2017 이화간호학회지 Vol.- No.51

Purpose: This study aims to identify the effects of self-esteem, relationship with children, Social Networking Services(SNS) use intensity on depression in middle-aged women with college-age children, and to provide basic data for the health promotion of middle-aged women. Method: A sample of 133 middle-aged people was purposely selected from parents of university students. Questionnaires used for this study were CES-D(The Center for Epidemiological Studies-Depression Scale), Self-esteem Scale, Relationship with Children Scale, SNS Intensity Scale. The collected data was analyzed by SPSS 21 with descriptive statistics, independent t-test, ANOVAs, Pearson correlation, multiple regression. Result: Self-esteem was correlated with relationship with children (r=0.385, p<0.01) and depression (r=-0.440, p<0.01). Relationship with children was correlated with depression(r=-0.402, p<0.01). As a result, a factor having the greatest influence on the subject's depression degree was self-esteem(β=-0.335), followed by relationship with children(β=-0.274). Conclusion: The result of this study suggested that depression in middle-aged women is closely related to self-esteem and relationship with children. This result can be used in Nursing by developing the theoretical basis for education program related to enhancing self-esteem and relationship with children.

Synthesis and characterization of ampelopsin glucosides using dextransucrase from Leuconostoc mesenteroides B-1299CB4: Glucosylation enhancing physicochemical properties

Woo, H.J.,Kang, H.K.,Nguyen, T.T.H.,Kim, G.E.,Kim, Y.M.,Park, J.S.,Kim, D.,Cha, J.,Moon, Y.H.,Nam, S.H.,Xia, Y.m.,Kimura, A.,Kim, D. IPC Science and Technology Press ; Elsevier Scienc 2012 Enzyme and microbial technology Vol.51 No.6

Novel ampelopsin glucosides (AMPLS-Gs) were enzymatically synthesized and purified using a Sephadex LH-20 column. Each structure of the purified AMPLS-Gs was determined by nuclear magnetic resonance, and the ionic product of AMPLS-G1 was observed at m/z 505 (C<SUB>21</SUB>H<SUB>22</SUB>O<SUB>13</SUB>.Na)<SUP>+</SUP> using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. AMPLS-G1 was identified as ampelopsin-4'-O-α-d-glucopyranoside. The optimum condition for AMPLS-G1, determined using response surface methodology, was 70mM ampelopsin, 150mM sucrose, and 1U/mL dextransucrase, which resulted in an AMPLS-G1 yield of 34g/L. The purified AMPLS-G1 displayed 89-fold increased water solubility and 14.5-fold browning resistance compared to those of AMPLS and competitive inhibition against tyrosinase with a K<SUB>i</SUB> value of 40.16μM. This value was smaller than that of AMPLS (K<SUB>i</SUB>=62.56μM) and much smaller than that of β-arbutin (K<SUB>i</SUB>=514.84μM), a commercial active ingredient of whitening cosmetics. These results indicate the potential of AMPLS and AMPLS-G1 as superior ingredients for functional cosmetics.

S–N Fatigue and Fatigue Crack Propagation Behaviors of X80 Steel at Room and Low Temperatures

Jung, D. H.,Kwon, J. K.,Woo, N. S.,Kim, Y. J.,Goto, M.,Kim, S. Springer Science + Business Media 2014 Metallurgical and Materials Transactions A - Physi Vol.45 No.2

<P>In the present study, the S-N fatigue and the fatigue crack propagation (FCP) behaviors of American Petroleum Institute X80 steel were examined in the different locations of the base metal (BM), weld metal (WM), and heat-affected zone (HAZ) at 298 K, 223 K, and 193 K (25 degrees C, 50 degrees C, and 80 degrees C). The resistance to S-N fatigue of X80 BM specimen increased greatly with decreasing temperature from 298 K to 193 K (25 degrees C to -80 degrees C) and showed a strong dependency on the flow strength (1/2(yield strength + tensile strength)). The FCP rates of X80 BM specimen were substantially reduced with decreasing temperature from 298 K to 223 K (25 degrees C to 50 degrees C) over the entire Delta K regime, while further reduction in FCP rates was not significant with temperature from 223 K to 193 K (-50 degrees C to -80 degrees C). The FCP rates of the X80 BM and the WM specimens were comparable with each other, while the HAZ specimen showed slightly better FCP resistance than the BM and the WM specimens over the entire Delta K regime at 298 K (25 degrees C). Despite the varying microstructural characteristics of each weld location, the residual stress appeared to be a controlling factor to determine the FCP behavior. The FCP behaviors of high strength X80 steel were discussed based on the microstructural and the fractographic observations. (C) The Minerals, Metals & Materials Society and ASM International 2013</P>