Interference Effect betweenϕandΛ(1520)Production Channels in theγp→K+K−pReaction near Threshold

Ryu, S. Y.,Ahn, J. K.,Nakano, T.,Ahn, D. S.,Ajimura, S.,Akimune, H.,Asano, Y.,Chang, W. C.,Chen, J. Y.,Daté,, S.,Ejiri, H.,Fujimura, H.,Fujiwara, M.,Fukui, S.,Hasegawa, S.,Hicks, K.,Horie, K.,Ho American Physical Society 2016 Physical Review Letters Vol.116 No.23

<P>The phi-Lambda(1520) interference effect in the gamma p -> K(+)K(-)p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between phi and Lambda(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K+K- pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the root s = 2.1 GeV bump structure in forward differential cross sections for phi photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.</P>

Isolation and partial characterization of a bacteriocin produced by <i>Pediococcus pentosaceus</i> K23-2 isolated from Kimchi

Shin, M.S.,Han, S.K.,Ryu, J.S.,Kim, K.S.,Lee, W.K. Blackwell Publishing Ltd 2008 Journal of Applied Microbiology Vol.105 No.2

<P>Abstract</P><P>Aims: </P><P>Screening and partial characterization of a bacteriocin produced by <I>Pediococcus pentosaceus</I> K23-2 isolated from Kimchi, a traditional Korean fermented vegetable.</P><P>Methods and Results: </P><P>A total of 1000 lactic acid bacteria were isolated from various Kimchi samples and screened for the production of bacteriocin. Pediocin K23-2, a bacteriocin produced by the <I>Pediococcus pentosaceus</I> K23-2 strain, showed strong inhibitory activity against <I>Listeria monocytogenes</I>. The bacteriocin activity remained unchanged after 15 min of heat treatment at 121°C or exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. The bacteriocin was maximally produced at 37°C, when the pH of the culture broth was maintained at 5·0 during the fermentation, although the optimum pH for growth was 7·0. The molecular weight of the bacteriocin was about 5 kDa according to a tricine SDS-PAGE analysis.</P><P>Conclusions: </P><P><I>Pediococcus pentosaceus</I> K23-2 isolated from Kimchi produces a bacteriocin, which shares similar characteristics to the Class IIa bacteriocins. The bacteriocin is heat stable and shows wide antimicrobial activity against Gram-positive bacteria, especially <I>L. monocytogenes</I>.</P><P>Significance and Impact of the Study: </P><P>Pediocin K23-2 and pediocin K23-2-producing <I>P. pentosaceus</I> K23-2 could potentially be used in the food and feed industries as natural biopreservatives, and for probiotic application to humans or livestock.</P>

OGLE-2016-BLG-1190Lb: The First<i>Spitzer</i>Bulge Planet Lies Near the Planet/Brown-dwarf Boundary

Ryu, Y.-H.,Yee, J. C.,Udalski, A.,Bond, I. A.,Shvartzvald, Y.,Zang, W.,Jaimes, R. Figuera,Jørgensen, U. G.,Zhu, W.,Huang, C. X.,Jung, Y. K.,Albrow, M. D.,Chung, S.-J.,Gould, A.,Han, C.,Hwang, K.-H.,Sh American Astronomical Society 2018 The Astronomical journal Vol.155 No.1

<P>We report the discovery of OGLE-2016-BLG-1190Lb, which is likely to be the first Spitzer microlensing planet in the Galactic bulge/ bar, an assignation that can be confirmed by two epochs of high-resolution imaging of the combined source-lens baseline object. The planet's mass, M-p = 13.4 +/- 0.9 M-J, places it right at the deuteriumburning limit, i. e., the conventional boundary between 'planets' and 'brown dwarfs.' Its existence raises the question of whether such objects are really ' planets' (formed within the disks of their hosts) or 'failed stars' (lowmass objects formed by gas fragmentation). This question may ultimately be addressed by comparing disk and bulge/bar planets, which is a goal of the Spitzer microlens program. The host is a G dwarf, M-host = 0.89. +/- 0.07 M-circle dot, and the planet has a semimajor axis a similar to 2.0 au. We use Kepler K2 Campaign 9 microlensing data to break the lens-mass degeneracy that generically impacts parallax solutions from Earth-Spitzer observations alone, which is the first successful application of this approach. The microlensing data, derived primarily from near-continuous, ultradense survey observations from OGLE, MOA, and three KMTNet telescopes, contain more orbital information than for any previous microlensing planet, but not quite enough to accurately specify the full orbit. However, these data do permit the first rigorous test of microlensing orbital-motion measurements, which are typically derived from data taken over < 1% of an orbital period.</P>

OGLE-2016-BLG-0693LB: Probing the Brown Dwarf Desert with Microlensing

Ryu, Y.-H.,Udalski, A.,Yee, J. C.,Albrow, M. D.,Chung, S.-J.,Gould, A.,Han, C.,Hwang, K.-H.,Jung, Y. K.,Shin, I.-G.,Zhu, W.,Cha, S.-M.,Kim, D.-J.,Kim, H.-W.,Kim, S.-L.,Lee, C.-U.,Lee, Y.,Park, B.-G.,P American Astronomical Society 2017 The Astronomical journal Vol.154 No.6

<P>We present an analysis of microlensing event OGLE-2016-BLG-0693, based on the survey-only microlensing observations by the OGLE and KMTNet groups. In order to analyze the light curve, we consider the effects of parallax, orbital motion, and baseline slope, and also refine the result using a Galactic model prior. From the microlensing analysis, we find that the event is a binary composed of a low-mass brown dwarf (49(-18)(+20) Mj) companion and a K- or G-dwarf host, which lies at a distance of 5.0 +/- 0.6 kpc toward the Galactic bulge. The projected separation between the brown dwarf and its host star is less than similar to 5 au, thus it is likely that the brown dwarf companion is located in the brown dwarf desert.</P>

Fluctuations in the ionosphere related to Honshu Twin Large Earthquakes of September 2004 observed by the DEMETER and CHAMP satellites

Ryu, K.,Chae, J.-S.,Lee, E.,Parrot, M. Elsevier Science Ltd ; Pergamon 2014 Journal of Atmospheric and Solar-Terrestrial Physi Vol.121 No.1

While investigating possible precursory signatures of large earthquakes in the ionospheric data measured by the DEMETER and CHAMP satellites, we found ionospheric disturbances related to large earthquakes (M=7.2 and 7.4) that occurred on September 2004 near the south coast of Honshu, Japan. The satellite data were statistically compared with an empirical model and local averages of the large set of data in the study period. A fluctuation in the electron density above the epicenter was observed roughly 2weeks before the main earthquakes. Surveys of the space weather and geomagnetic activities suggest that these fluctuations were not caused by changes in space conditions or by a geomagnetic storm. The features were also distinct from well-known natural ionospheric anomalies. In addition, a peak-like profile in the ion temperature and lowered O<SUP>+</SUP> density around the region of the epicenter was observed a week before the main earthquakes along the satellite passes whose longitudes are close to the epicenter. The features are more apparent when they are compared with the data more distant from the epicenter, suggesting that the disturbances occur along the geomagnetic field lines. The concurrent measurements of the ion drift velocity suggest the fluctuations were triggered by the vertical plasma drift. The observed anomalies disappeared ~2 weeks after the quakes. According to the current theories on the seismo-ionospheric coupling, the horizontal electric field at the lower boundary of the ionosphere should have been strengthened by the seismic activity in order for the ionospheric plasma movements above the epicenter and its geomagnetic conjugate regions to trigger the observed ionospheric anomalies.

In vitro and in vivo antifungal activities of decursin and decursinol angelate isolated from Angelica gigas against Magnaporthe oryzae, the causal agent of rice blast

Yoon, M.Y.,Kim, Y.S.,Ryu, S.Y.,Choi, G.J.,Choi, Y.H.,Jang, K.S.,Cha, B.,Han, S.S.,Kim, J.C. Academic Press 2011 Pesticide biochemistry and physiology Vol.101 No.2

Blast is considered the most important fungal disease of rice due to its wide distribution and destructiveness under favorable conditions. Development of new effective and environmentally benign agents against the causal pathogen, Magnaporthe oryzae, is of great interest. In the course of a search for natural antifungal compounds in medicinal plants, we found that the methanol extract of Angelica gigas roots showed a potent control efficacy against rice blast caused by M. oryzae. We isolated antifungal coumarins from the extract, and they were identified as decursin and decursinol angelate. Antifungal activities of these compounds, along with kasugamycin, were tested on M. oryzae in vivo and in vitro. In an in vivo assay, the three compounds effectively suppressed the development of rice blast at concentrations more than 100μg/mL. Coumarins showed relatively weak inhibitory effect on fungal mycelial growth when compared to kasugamycin. However, they strongly inhibited M. oryzae spore germination, which was not observed in kasugamycin treatments. This is the first report demonstrating that decursinol angelate can provide control against rice blast and that the two coumarins inhibit M. oryzae spore germination. In addition, the wettable powder formulation of the crude extract of A. gigas prohibited the development of blast symptoms on rice plants more effectively than liquid concentrate formulation of kasugamin, a commercial fungicide. Based on our study, we propose that coumarin compounds as well as the A. gigas root crude extract can be used as natural, benign fungicides for controlling rice blast.

디프테리아 및 破傷風에 對한 免疫 血淸學的 調査硏究 : Antitoxin Levels in the Human Sera 1974

鄭三逵,金景俊,趙敏基,柳在根,朴京錫 國立保健硏究院 1974 국립보건연구원보 Vol.11 No.-

Potential pancreatic lipase inhibitory activity of phenolic constituents from the root bark of Morus alba L.

Ha, M.T.,Tran, M.H.,Ah, K.J.,Jo, K.J.,Kim, J.,Kim, W.D.,Cheon, W.J.,Woo, M.H.,Ryu, S.H.,Min, B.S. Pergamon Press 2016 Bioorganic & medicinal chemistry letters Vol.26 No.12

Detailed phytochemical investigation from the root bark of Morus alba resulted in the isolation of eleven new compounds, including seven 2-arylbenzofuran derivatives (morusalfurans A-G), three flavonoids (morusalnols A-C), and one geranylated stilbene (morusibene A), as well as 22 known compounds. The structures of the identified compounds were elucidated based on a comprehensive analysis of spectroscopic data and Mosher's method. Compounds 2, 3, 6-8, 11, 23, 24, and 29 showed potent inhibition of PL in comparison with the positive control treatment (orlistat, IC<SUB>50</SUB>=0.012μM), with IC<SUB>50</SUB> values ranging from 0.09 to 0.92μM.

Histamine에 의한 위궤양 발생기전에 관하여

구명숙,김광주,김미경A,유경하 이화여자대학교 의과대학 1982 梨花醫學誌 Vol.- No.14

Histamine and Reserpine increased gastric secretion and free acidity, as a result they produced peptic ulceration. Cimetidime, a H_2 receptor antagonist, blocked the increase of gastric secretion and acidity In this experiment, some aspects of histamine, reserpine, and cimetidine on gastric secretion and ulceration in rat were studied. The data reported showes that; 1) Histamine treated group increased gastric volume and free acidity, compared with those of control group. But total acidity was decreased. Gastric mucosa showed significant gross hemorrhage and ulceration 2) Reserpine treated group showed significant increase in gastric volume and pH, slight increase in free acidity. But Total acidity decreased remarkably. 3) In cimetidine pretreated groups, gastric volume, pH, and free acidity were not increased. Total acidity was decreased remarkably. Ulceration of gastric mucosa was slightly occured. In conclusion, histamine and reserpine increased gastric volume and free acidity. They produced peptic ulceration on the mechanism of H^+ion back diffusion. Cimetidine pretreated group blocked gastric ulceration.

Phase II study of S-1 combined with oxaliplatin as therapy for patients with metastatic biliary tract cancer: influence of the <i>CYP2A6</i> polymorphism on pharmacokinetics and clinical activity

Kim, K-p,Jang, G,Hong, Y S,Lim, H-S,Bae, K-s,Kim, H-S,Lee, S S,Shin, J-G,Lee, J-L,Ryu, M-H,Chang, H-M,Kang, Y-K,Kim, T W Nature Publishing Group 2011 The British journal of cancer Vol.104 No.4

<P><B>Background:</B></P><P>Advanced biliary cancer is often treated with fluoropyrimidine-based chemotherapy. In this study, we evaluated the efficacy and tolerability of a combination of S-1, an oral fluoropyrimidine prodrug, and oxaliplatin in patients with metastatic biliary cancer.</P><P><B>Methods:</B></P><P>Patients with histologically confirmed metastatic biliary cancer and no history of radiotherapy or chemotherapy were enrolled. Oxaliplatin was administered intravenously (130 mg m<SUP>−2</SUP>), followed by 14-day administration of oral S-1 (40 mg m<SUP>−2</SUP> twice daily) with a subsequent 7-day rest period every 21 days. Pharmacokinetic analysis of S-1 was performed at cycle 1. Patients were genotyped for <I>CYP2A6</I> polymorphisms (<SUP>*</SUP>1, <SUP>*</SUP>4, <SUP>*</SUP>7, <SUP>*</SUP>9 or <SUP>*</SUP>10), and pharmacokinetic and clinical parameters compared according to the <I>CYP2A6</I> genotype.</P><P><B>Results:</B></P><P>In total, 49 patients were evaluated, who received a median of four cycles. The overall response rate was 24.5%. Median progression-free and overall survival was 3.7 and 8.7 months, respectively. The most common haematological grade 3 out of 4 toxicity was neutropenia (14%), while non-hematological grade 3 out of 4 toxicities included anorexia (14%), nausea (12%), asthenia (10%), vomiting (10%), and diarrhoea (4%). Biotransformation of S-1 (AUC<SUB>0−24 h</SUB> of 5-fluorouracil/AUC<SUB>0−24 h</SUB> of tegafur) was 1.85-fold higher for the <I>*1/*1</I> group than for the other groups (90% confidence interval 1.37–2.49). Diarrhoea (<I>P</I>=0.0740), neutropenia (<I>P</I>=0.396), and clinical efficacy (response rate, <I>P</I>=0.583; PFS, <I>P</I>=0.916) were not significantly associated with <I>CYP2A6</I> genotype, despite differences in 5-FU exposure.</P><P><B>Conclusion:</B></P><P>The combination of S-1 and oxaliplatin appears to be active and well tolerated in patients with metastatic biliary cancer, and thus is feasible as a therapeutic modality. <I>CYP2A6</I> genotypes are associated with differences in the biotransformation of S-1. However, the impact of the <I>CYP2A6</I> polymorphism on variations in clinical efficacy or toxicity requires further evaluation.</P>