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Noh YH, Chob HS, Kim DH, Kim OH, Park J, Lee SA, Yang HS, Sohn DS, Kim W, Kim D, Chung YH, Kim KY, Kim SS, Lee WB. N-acetylcysteine enhances neuronal differentiation of P19 embryonic stem cells via Akt and N-cadherin activation. Mol Biol (Mosk) 2012; 46:741-746. [PMID: 23156673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We examined whether N-acetylcysteine (NAC) enhanced embryonic body (EB) formation and neuronal differentiation in terms of EB formation, neuronal marker (microtubule-associated protein 2; MAP-2) expression, and neuron maturation using P19 embryonic stem cells. The size and numbers of EBs were greatly increased, together with the up-regulated N-cadherin expression. Also, MAP-2 expression and neurite outgrowth were much increased with activation of serine/threonine protein kinase (Akt) and blocked by addition of an Akt inhibitor (LY294002). Our results suggested that NAC increased EB formation by up-regulating the N-cadherin expression. Furthermore, NAC-enhanced neuronal differentiation was mediated by activation of Akt.
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Oh TI, You YS, Kim KY. Two-dimensional plasma current and optimized terahertz generation in two-color photoionization. OPTICS EXPRESS 2012; 20:19778-19786. [PMID: 23037030 DOI: 10.1364/oe.20.019778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Two-dimensional (2-D) transverse photocurrent generation is studied and applied to control and optimize terahertz energy and polarization in two-color, laser-produced air filaments. A full control of terahertz output is demonstrated and explained in the context of 2-D photocurrent model.
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Kim YS, Kang SJ, Kim JW, Cho HR, Moon SB, Kim KY, Lee HS, Han CH, Ku SK, Lee YJ. Effects of Polycan, a β-glucan, on experimental periodontitis and alveolar bone loss in Sprague-Dawley rats. J Periodontal Res 2012; 47:800-10. [PMID: 22780690 DOI: 10.1111/j.1600-0765.2012.01502.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVE Polycan is a promising candidate for the treatment of periodontal disease. This study was undertaken to examine whether Polycan, a type of β-glucan, has a protective effect on ligature-induced experimental periodontitis and related alveolar bone loss in Sprague-Dawley rats. MATERIAL AND METHODS Polycan was orally administered, daily, for 10 d, at 21.25, 42.5 or 85 mg/kg, beginning 1 d after ligation. Changes in body weight and alveolar bone loss were monitored, and the anti-inflammatory effects of Polycan were determined by measuring the levels of myeloperoxidase (MPO), interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in gingival tissue. We also evaluated inducible nitric oxide synthase (iNOS) activity and malondialdehyde (MDA) concentrations as a measure of the antioxidant effect. RESULTS Ligature placement led to a marked decrease in body weight, increased alveolar bone loss and increased concentrations of MPO, IL-1β, TNF-α and MDA, as well as increased iNOS activity and inflammatory cell infiltration and decreased collagen-fiber content. Histological examination revealed increases in the number and activity of osteoclast cells, decreases in alveolar bone volume and elevated percentages of osteclasts on the alveolar bone surface. Daily oral treatment with 42.5 or 85 mg/kg of Polycan for 10 d led to significant, dose-dependent inhibition of the effect of ligature placement. CONCLUSION Taken together, these results suggest that 10 d of oral treatment with Polycan effectively inhibits ligature placement-induced periodontitis and related alveolar bone loss via an antioxidant effect.
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Han WS, Kim KY, Park E, McPherson BJ, Lee SY, Park MH. Modeling of Spatiotemporal Thermal Response to CO2 Injection in Saline Formations: Interpretation for Monitoring. Transp Porous Media 2012. [DOI: 10.1007/s11242-012-9957-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Avila C, Huang RJ, Stevens MV, Aponte AM, Tripodi D, Kim KY, Sack MN. Platelet mitochondrial dysfunction is evident in type 2 diabetes in association with modifications of mitochondrial anti-oxidant stress proteins. Exp Clin Endocrinol Diabetes 2011; 120:248-51. [PMID: 21922457 DOI: 10.1055/s-0031-1285833] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Mitochondrial dysfunction and oxidative stress in insulin responsive tissues is implicated in the pathogenesis of type 2 diabetes. Whether these perturbations extend to other tissues and contribute to their pathophysiology is less well established. The objective of this study was to investigate platelet mitochondria to evaluate whether type 2 diabetes associated mitochondrial dysfunction is evident in circulating cells. METHOD A pilot study of mitochondrial respiratory function and proteomic changes comparing platelets extracted from insulin sensitive (n=8) and type 2 diabetic subjects (n=7). RESULTS In-situ platelet mitochondria show diminished oxygen consumption and lower oxygen-dependent ATP synthesis in diabetic vs. control subjects. Mass spectrometric identification and confirmatory immunoblot analysis identifies induction of the mitochondrial anti-oxidant enzymes superoxide dismutase 2 and thioredoxin-dependent peroxide reductase 3 in platelets of diabetic subjects. As oxidative stress upregulates anti-oxidant enzymes we assessed mitochondrial protein carbonylation as an index of oxidative-stress. Platelets of diabetic subjects exhibit significantly increased protein carbonylation compared to controls. CONCLUSIONS As platelets are anuclear fragments of megakaryocytes, our data suggest that the bone marrow compartment in type 2 diabetic subjects is exposed to increased mitochondrial oxidative stress with upregulation of nuclear-encoded antioxidant mitochondrial enzymes. This 'stress-signature' in platelets of diabetic subjects is associated with a diminution of their mitochondrial contribution to energy production and support that mitochondrial perturbations in type 2 diabetes extends beyond the classical insulin responsive tissues. Platelets, as "accessible human tissue", may be useful to measure the mitochondrial modulatory effects of emerging anti-diabetic therapeutics.
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Han WS, Kim KY, Esser RP, Park E, McPherson BJ. Sensitivity Study of Simulation Parameters Controlling CO2 Trapping Mechanisms in Saline Formations. Transp Porous Media 2011. [DOI: 10.1007/s11242-011-9817-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Park K, Kim KY. Synthesis and photoluminescence of nano-sized (Gd,Y)PO4:Eu3+ by solution combustion method. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2011; 11:7361-7364. [PMID: 22103196 DOI: 10.1166/jnn.2011.4774] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We synthesized (Gd(1-x)Yx)(0.94)PO4:Eu(0.06) (0 < or = x < or = 1.0) phosphor powders of an ultra-fine size (approximately 23 nm), smooth surface, and spherical and regular morphologies by the solution combustion method. The crystallite sizes of the annealed (Gd(1-x)Yx)(0.94)PO4:Eu(0.06) phosphors with x = 0, 0.25, 0.5, 0.75, and 1.0 were 63.3, 62.3, 49.9, 45.1, and 43.3 nm, respectively. The photoluminescent characteristics of the phosphors were studied under vacuum ultraviolet excitation, depending on the Y3+ concentration. The intensity of the peaks corresponding to the red emission increased with increases in the Y3+ concentration. The Y(0.94)PO4:Eu(0.06) phosphor emitted the strongest intensity and the purest red color.
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Rashid A, Kim BS, Khambampati AK, Kim S, Kim KY. An oppositional biogeography-based optimization technique to reconstruct organ boundaries in the human thorax using electrical impedance tomography. Physiol Meas 2011; 32:767-96. [DOI: 10.1088/0967-3334/32/7/s04] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kim JH, Kim HS, Seo WY, Nam CM, Kim KY, Jeung HC, Lai JF, Chung HC, Noh SH, Rha SY. External validation of nomogram for the prediction of recurrence after curative resection in early gastric cancer. Ann Oncol 2011; 23:361-7. [PMID: 21566150 DOI: 10.1093/annonc/mdr118] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Nomograms are statistics-based tools that provide the overall probability of a specific outcome. In our previous study, we developed a nomogram that predicts recurrence of early gastric cancer (EGC) after curative resection. We carried out this study to externally validate our EGC nomogram. PATIENTS AND METHODS The EGC nomogram was established from a retrospective EGC database that included 2923 consecutive patients. This nomogram was independently externally validated for a cohort of 1058 consecutive patients. For the EGC nomogram validation, we assessed both discrimination and calibration. RESULTS Within the follow-up period (median 37 months), a total of 11 patients (1.1%) experienced recurrence. The concordance index (c-index) was 0.7 (P = 0.02) and the result of the overall C index was 0.82 [P = 0.006, 95% confidence interval (CI) 0.59-1.00]. The goodness of fit test showed that the EGC nomogram had significantly good fit for 1- and 2-year survival intervals (P = 0.998 and 0.879, respectively). The actual and predicted survival outcomes showed good agreement, suggesting that the survival predictions from the nomogram are well calibrated externally. CONCLUSIONS A preexisting nomogram for predicting disease-free survival (DFS) of EGC after surgery was externally validated. The nomogram is useful for accurate and individual prediction of DFS, patient prognostication, counseling, and follow-up planning.
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Ryu JJ, Yoo S, Kim KY, Park JS, Bang S, Lee SH, Yang TJ, Cho H, Hwang SW. Laser modulation of heat and capsaicin receptor TRPV1 leads to thermal antinociception. J Dent Res 2010; 89:1455-60. [PMID: 20935279 DOI: 10.1177/0022034510381394] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Er,Cr:YSGG lasers are used clinically in dentistry. The advantages of laser therapy include minimal thermal damage and the alleviation of pain. This study examined whether the Er,Cr:YSGG laser has in vivo and in vitro antinociceptive effects in itself. In capsaicin-evoked acute licking/shaking tests and Hargreaves tests, laser irradiation with an aerated water spray suppressed nociceptive behavior in mice. Laser irradiation attenuated TRPV1 activation by capsaicin in Ca(2+) imaging experiments with TRPV1-overexpressing cells and cultured trigeminal neurons. Therefore, the laser-induced behavioral changes are probably due to the loss of TRPV1 activity. TRPV4 activity was also attenuated, but limited mechanical antinociception by the laser was observed. The laser failed to alter the other receptor functions, which indicates that the antinociceptive effect of the laser is dependent on TRPV1. These results suggest that the Er,Cr:YSGG laser has analgesic effects via TRPV1 inhibition. Such mechanistic approaches may help define the laser-sensitive pain modality and increase its beneficial uses.
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Kim KY, Ju WK, Hegedus B, Gutmann DH, Ellisman MH. Ultrastructural characterization of the optic pathway in a mouse model of neurofibromatosis-1 optic glioma. Neuroscience 2010; 170:178-88. [PMID: 20600672 DOI: 10.1016/j.neuroscience.2010.06.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 06/08/2010] [Accepted: 06/09/2010] [Indexed: 12/30/2022]
Abstract
The purpose of this study was to investigate the progression of changes in retinal ganglion cells and optic nerve glia in neurofibromatosis-1 (NF1) genetically-engineered mice with optic glioma. Optic glioma tumors were generated in Nf1+/- mice lacking Nf1 expression in GFAP+ cells (astrocytes). Standard immunohistochemistry methods were employed to identify astrocytes (GFAP, S100beta), proliferating progenitor cells (sox2, nestin), microglia (Iba1), endothelial cells (CD31) and retinal ganglion cell (RGC) axons (Neurofilament 68k) in Nf1+/-, Nf1(GFAP)CKO (wild-type mice with Nf1 loss in glial cells), and Nf1+/-(GFAP)CKO (Nf1+/- mice with Nf1 loss in glial cells) mice. Ultrastructural changes in the optic chiasm and nerve were assessed by electron microscopy (EM). RGC were counted in whole retina preparations using high-resolution, mosaic confocal microscopy following their delineation by retrograde FluoroGold labeling. We found that only Nf1+/-(GFAP)CKO mice exhibited gross pre-chiasmatic optic nerve and chiasm enlargements containing aggregated GFAP+/nestin+ and S100beta+/sox2+ cells (neoplastic glia) as well as increased numbers of blood vessels and microglia. Optic gliomas in Nf1+/-(GFAP)CKO mice contained axon fiber irregularities and multilamellar bodies of degenerated myelin. EM and EM tomographic analyses showed increased glial disorganization, disoriented axonal projections, profiles of degenerating myelin and structural alterations at nodes of Ranvier. Lastly, we found reduced RGC numbers in Nf1+/-(GFAP)CKO mice, supporting a model in which the combination of optic nerve Nf1 heterozygosity and glial cell Nf1 loss results in disrupted axonal-glial relationships, subsequently culminating in the degeneration of optic nerve axons and loss of their parent RGC neurons.
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Kim YC, Ko Y, Hong SD, Kim KY, Lee YH, Chae C, Choi Y. Presence ofPorphyromonas gingivalisand plasma cell dominance in gingival tissues with periodontitis. Oral Dis 2010; 16:375-81. [DOI: 10.1111/j.1601-0825.2009.01649.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lachniet J, Afanasev A, Arenhövel H, Brooks WK, Gilfoyle GP, Higinbotham D, Jeschonnek S, Quinn B, Vineyard MF, Adams G, Adhikari KP, Amaryan MJ, Anghinolfi M, Asavapibhop B, Asryan G, Avakian H, Bagdasaryan H, Baillie N, Ball JP, Baltzell NA, Barrow S, Batourine V, Battaglieri M, Beard K, Bedlinskiy I, Bektasoglu M, Bellis M, Benmouna N, Berman BL, Biselli AS, Bonner BE, Bookwalter C, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Bültmann S, Burkert VD, Calarco JR, Careccia SL, Carman DS, Casey L, Cheng L, Cole PL, Coleman A, Collins P, Cords D, Corvisiero P, Crabb D, Crede V, Cummings JP, Dale D, Daniel A, Dashyan N, De Masi R, De Vita R, De Sanctis E, Degtyarenko PV, Denizli H, Dennis L, Deur A, Dhamija S, Dharmawardane KV, Dhuga KS, Dickson R, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Dzyubak OP, Egiyan H, Egiyan KS, El Fassi L, Elouadrhiri L, Empl A, Eugenio P, Fatemi R, Fedotov G, Fersch R, Feuerbach RJ, Forest TA, Fradi A, Gabrielyan MY, Garçon M, Gavalian G, Gevorgyan N, Giovanetti KL, Girod FX, Goetz JT, Gohn W, Golovatch E, Gothe RW, Graham L, Griffioen KA, Guidal M, Guillo M, Guler N, Guo L, Gyurjyan V, Hadjidakis C, Hafidi K, Hakobyan H, Hanretty C, Hardie J, Hassall N, Heddle D, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hu J, Huertas M, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Ito MM, Jenkins D, Jo HS, Johnstone JR, Joo K, Juengst HG, Kageya T, Kalantarians N, Keller D, Kellie JD, Khandaker M, Khetarpal P, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klusman M, Konczykowski P, Kossov M, Kramer LH, Kubarovsky V, Kuhn J, Kuhn SE, Kuleshov SV, Kuznetsov V, Laget JM, Langheinrich J, Lawrence D, Lima ACS, Livingston K, Lowry M, Lu HY, Lukashin K, Maccormick M, Malace S, Manak JJ, Markov N, Mattione P, McAleer S, McCracken ME, McKinnon B, McNabb JWC, Mecking BA, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Mineeva T, Minehart R, Mirazita M, Miskimen R, Mokeev V, Moreno B, Moriya K, Morrow SA, Moteabbed M, Mueller J, Munevar E, Mutchler GS, Nadel-Turonski P, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niroula MR, Niyazov RA, Nozar M, O'Rielly GV, Osipenko M, Ostrovidov AI, Park K, Park S, Pasyuk E, Paterson C, Pereira SA, Philips SA, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Popa I, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Rosner G, Rossi P, Rowntree D, Rubin PD, Sabatié F, Saini MS, Salamanca J, Salgado C, Sandorfi A, Santoro JP, Sapunenko V, Schott D, Schumacher RA, Serov VS, Sharabian YG, Sharov D, Shaw J, Shvedunov NV, Skabelin AV, Smith ES, Smith LC, Sober DI, Sokhan D, Starostin A, Stavinsky A, Stepanyan S, Stepanyan SS, Stokes BE, Stoler P, Stopani KA, Strakovsky II, Strauch S, Suleiman R, Taiuti M, Taylor S, Tedeschi DJ, Thompson R, Tkabladze A, Tkachenko S, Ungaro M, Vlassov AV, Watts DP, Wei X, Weinstein LB, Weygand DP, Williams M, Wolin E, Wood MH, Yegneswaran A, Yun J, Yurov M, Zana L, Zhang J, Zhao B, Zhao ZW. Precise measurement of the neutron magnetic form factor G(M)n in the few-GeV2 region. PHYSICAL REVIEW LETTERS 2009; 102:192001. [PMID: 19518944 DOI: 10.1103/physrevlett.102.192001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Indexed: 05/27/2023]
Abstract
The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.
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Kim KY, Nam KA, Kurihara H, Kim SM. Potent alpha-glucosidase inhibitors purified from the red alga Grateloupia elliptica. PHYTOCHEMISTRY 2008; 69:2820-5. [PMID: 18951591 DOI: 10.1016/j.phytochem.2008.09.007] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2007] [Revised: 05/22/2008] [Accepted: 09/07/2008] [Indexed: 05/05/2023]
Abstract
Diabetes mellitus is a most serious and chronic disease whose incidence rates are increasing with incidences of obesity and aging of the general population over the world. One therapeutic approach for decreasing postprandial hyperglycemia is to retard absorption of glucose by inhibition of alpha-glucosidase. Two bromophenols, 2,4,6-tribromophenol and 2,4-dibromophenol, were purified from the red alga Grateloupia elliptica. IC(50) values of 2,4,6-tribromophenol and 2,4-dibromophenol were 60.3 and 110.4 microM against Saccharomyces cerevisiae alpha-glucosidase, and 130.3 and 230.3 microM against Bacillus stearothermophilus alpha-glucosidase, respectively. In addition, both mildly inhibited rat-intestinal sucrase (IC(50) of 4.2 and 3.6mM) and rat-intestinal maltase (IC(50) of 5.0 and 4.8mM). Therefore, bromophenols of G. elliptica have potential as natural nutraceuticals to prevent diabetes mellitus because of their high alpha-glucosidase inhibitory activity.
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Kim KY, Yellampalle B, Glownia JH, Taylor AJ, Rodriguez G. Measurements of terahertz electrical conductivity of intense laser-heated dense aluminum plasmas. PHYSICAL REVIEW LETTERS 2008; 100:135002. [PMID: 18517962 DOI: 10.1103/physrevlett.100.135002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Indexed: 05/26/2023]
Abstract
We report the electrical conductivity of laser-produced warm dense aluminum plasmas measured using single-shot ultrafast terahertz (THz) frequency spectroscopy. In contrast with experiments performed at optical frequencies, measurements based upon THz probe reflectivity directly determine a quasi-dc electrical conductivity, and therefore the analysis does not require a free-electron Drude model based extrapolation to recover the near zero frequency conductivity. In fact, our experimental results indicate that the Drude model breaks down for warm (>0.6 eV), moderate-dense (<1.6 g/cm(3)) aluminum at THz frequencies. A calculation of THz reflectivity over a non-Fresnel boundary in dense plasmas is also presented.
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Kim DM, Kim KY, Nam HS, Kweon SS, Park MY, Ryu SY. Risk-factors for human infection with Orientia tsutsugamushi: a case-control study in Korea. Clin Microbiol Infect 2007; 14:174-7. [PMID: 18070125 DOI: 10.1111/j.1469-0691.2007.01901.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A case-control study was conducted involving 156 patients with scrub typhus and 130 controls. Three factors were associated significantly with the risk of developing scrub typhus: engaging in fruit farming (OR 2.44; 95% CI 1.04-5.69), gathering chestnuts (OR 2.05; 95% CI 1.09-3.87) and taking breaks in areas adjacent to agricultural operations (OR 3.06; 95% CI 1.50-6.22). In contrast, receiving information or educational materials concerning the prevention of scrub typhus had a protective effect (OR 0.45; 95% CI 0.24-0.83). These results suggest that a health education programme will lower the risk of developing scrub typhus when applied to high-risk groups.
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Kim KY, Chon CM, Park KH. A simple method for locating the fresh water-salt water interface using pressure data. GROUND WATER 2007; 45:723-728. [PMID: 17973750 DOI: 10.1111/j.1745-6584.2007.00349.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Salt water intrusion is a key issue in dealing with exploitation, restoration, and management of fresh ground water in coastal aquifers. Constant monitoring of the fresh water-salt water interface is necessary for proper management of ground water resources. This study presents a simple method to estimate the depth of the fresh water-salt water interface in coastal aquifers using two sets of pressure data obtained from the fresh and saline zones within a single borehole. This method uses the density difference between fresh water and saline water and can practically be used at coastal aquifers that have a relatively sharp fresh water-salt water interface with a thin transition zone. The proposed method was applied to data collected from a coastal aquifer on Jeju Island, Korea, to estimate the variations in the depth of the interface. The interface varied with daily tidal fluctuations and heavy rainfall in the rainy season. The estimated depth of the interface showed a good agreement with the measured electrical conductivity profile.
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Kim KY, Yellampalle B, Taylor AJ, Rodriguez G, Glownia JH. Single-shot terahertz pulse characterization via two-dimensional electro-optic imaging with dual echelons. OPTICS LETTERS 2007; 32:1968-70. [PMID: 17632612 DOI: 10.1364/ol.32.001968] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A single-shot measurement of terahertz electromagnetic pulses is implemented using two-dimensional electro-optic imaging with dual echelon optics. The reported embodiment produces sequentially delayed multiprobe beamlets, routinely providing a time window of >10 ps with ~25 fs temporal step sizes. Because of its simplicity and robustness, the technique is ideally suited for real-time ultrashort relativistic electron bunch characterization.
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Kim HJ, Yang KY, Cho BH, Kim KY, Lee MC, Kim YH, Anderson AJ, Kim YC. Transcript accumulation from the rpoS gene encoding a stationary-phase sigma factor in Pseudomonas chlororaphis strain O6 is regulated by the polyphosphate kinase gene. Curr Microbiol 2007; 54:219-23. [PMID: 17294328 DOI: 10.1007/s00284-006-0361-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Accepted: 09/06/2006] [Indexed: 11/30/2022]
Abstract
Polyphosphate levels are modulated by the actions of polyphosphate kinase, encoded by ppk, and exopolyphosphatase, encoded by ppx. The genes ppk and ppx are adjacent to each other in the genome of the root colonizer, Pseudomonas chlororaphis O6. A ppk-deficient mutant was more sensitive to oxidative stress than the wild-type and the ppx mutant. Transcripts from ppx increased as cultures matured from mid- to late-logarithmic and stationary phases, whereas abundance was greater for ppk in the late-logarithmic phase than in the stationary phase. Transcript accumulation from the rpoS gene, encoding the stationary-phase sigma factor RpoS, was decreased in the mid- and late-logarithmic and stationary phases in the ppk mutant. Thus, ppk regulates rpoS transcript accumulation in P. chlororaphis 06. However, mutations in either the ppk or ppx genes had no effect on induction of systemic resistance in plants colonized by P. chlororaphis O6.
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Yellampalle B, Kim KY, Rodriguez G, Glownia JH, Taylor AJ. Details of electro-optic terahertz detection with a chirped probe pulse. OPTICS EXPRESS 2007; 15:1376-1383. [PMID: 19532368 DOI: 10.1364/oe.15.001376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
By revisiting the theory of terahertz pulse detection schemes employing a chirped optical probe pulse, we address and resolve a conflict that exists in literature. In this report, we show that the equation governing the detected field depends upon the experimental scheme, and in the limit of small bandwidth, that this expression differs from the conventionally used equation through a phase factor. We experimentally verify this equation using a spectral in-line interferometry approach. We also briefly discuss the implications of our new equations for single-shot terahertz retrieval schemes.
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Chen S, Avakian H, Burkert VD, Eugenio P, Adams G, Amarian M, Ambrozewicz P, Anghinolfi M, Asryan G, Bagdasaryan H, Baillie N, Ball JP, Baltzell NA, Barrow S, Batourine V, Battaglieri M, Beard K, Bedlinskiy I, Bektasoglu M, Bellis M, Benmouna N, Berman BL, Biselli AS, Bonner BE, Bouchigny S, Boiarinov S, Bosted P, Bradford R, Branford D, Briscoe WJ, Brooks WK, Bültmann S, Butuceanu C, Calarco JR, Careccia SL, Carman DS, Carnahan B, Cazes A, Cole PL, Collins P, Coltharp P, Cords D, Corvisiero P, Crabb D, Crannell H, Crede V, Cummings JP, DeMasi R, DeVita R, De Sanctis E, Degtyarenko PV, Denizli H, Dennis L, Deur A, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Donnelly J, Doughty D, Dugger M, Dytman S, Dzyubak OP, Egiyan H, Egiyan KS, El Fassi L, Elouadrhiri L, Fatemi R, Fedotov G, Feldman G, Feuerbach RJ, Forest TA, Funsten H, Garçon M, Gavalian G, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz JT, Golovatch E, Gonenc A, Gothe RW, Griffioen KA, Guidal M, Guillo M, Guler N, Guo L, Gyurjyan V, Hadjidakis C, Hafidi K, Hakobyan H, Hakobyan RS, Hardie J, Heddle D, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Huertas M, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Ito MM, Jenkins D, Jo HS, Joo K, Juengst HG, Keith C, Kellie JD, Khandaker M, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klusman M, Kossov M, Kramer LH, Kubarovsky V, Kuhn J, Kuhn SE, Kuleshov SV, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Li J, Lima ACS, Livingston K, Lu H, Lukashin K, MacCormick M, Markov N, McAleer S, McKinnon B, McNabb JWC, Mecking BA, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Morand L, Morrow SA, Moteabbed M, Mueller J, Mutchler GS, Nadel-Turonski P, Napolitano J, Nasseripour R, Natasha N, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niroula MR, Niyazov RA, Nozar M, O'Rielly GV, Osipenko M, Ostrovidov AI, Park K, Pasyuk E, Paterson C, Philips SA, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Popa I, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rosner G, Rossi P, Rowntree D, Rubin PD, Sabatié F, Salgado C, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Shaw J, Shvedunov NV, Skabelin AV, Smith ES, Smith LC, Sober DI, Stavinsky A, Stepanyan SS, Stepanyan S, Stokes BE, Stoler P, Strakovsky II, Strauch S, Suleiman R, Taiuti M, Tedeschi DJ, Thoma U, Tkabladze A, Tkachenko S, Todor L, Tur C, Ungaro M, Vanderhaeghen M, Vineyard MF, Vlassov AV, Watts DP, Weinstein LB, Weygand DP, Williams M, Wolin E, Wood MH, Yegneswaran A, Yun J, Zana L, Zhang J, Zhao B, Zhao Z. Measurement of deeply virtual compton scattering with a polarized-proton target. PHYSICAL REVIEW LETTERS 2006; 97:072002. [PMID: 17026221 DOI: 10.1103/physrevlett.97.072002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Indexed: 05/12/2023]
Abstract
The longitudinal target-spin asymmetry AUL for the exclusive electroproduction of high-energy photons was measured for the first time in ep-->e;'pgamma. The data have been accumulated at JLab with the CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized NH3 target. A significant azimuthal angular dependence was observed, resulting from the interference of the deeply virtual Compton scattering and Bethe-Heitler processes. The amplitude of the sinvarphi moment is 0.252+/-0.042stat+/-0.020sys. Theoretical calculations are in good agreement with the magnitude and the kinematic dependence of the target-spin asymmetry, which is sensitive to the generalized parton distributions H and H.
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Kim KY, Milchberg HM, Faenov AY, Magunov AI, Pikuz TA, Skobelev IY. X-ray spectroscopy of 1 cm plasma channels produced by self-guided pulse propagation in elongated cluster jets. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 73:066403. [PMID: 16906984 DOI: 10.1103/physreve.73.066403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Indexed: 05/11/2023]
Abstract
We diagnose the self-channeled propagation of intense femtosecond pulses over an extended distance in a N2O cluster gas target using high resolution kilovolt x-ray pinhole images of the channel and spatially resolved x-ray spectra. The x-ray images are consistent with femtosecond optical scattering, shadowgraphy, and interferometry images. We observe extended plasma channels (approximately 9 mm) limited either by the cluster jet length or by absorption, for injected laser intensities in the range of 10(16)-10(17) W/cm2. Spectral line shapes for the OVII 1s2-1s3p and OVIII 1s-2p transitions (at 1.8627 and 1.8969 nm, respectively) show significant broadening to the blue side and with truncated emission on the red side. We attribute this effect to Doppler blueshifted emission from fast ions from exploding clusters moving toward the spectrometer; redshifted emission from the opposite side of the cluster is absorbed.
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Milchberg HM, Kim KY, Kumarappan V, Layer BD, Sheng H. Clustered gases as a medium for efficient plasma waveguide generation. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2006; 364:647-61. [PMID: 16483955 DOI: 10.1098/rsta.2005.1729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Clustered gas jets are shown to be an efficient means for plasma waveguide generation, for both femtosecond and picosecond generation pulses. These waveguides enable significantly lower on-axis plasma density (less than 10(18) cm(-3)) than in conventional hydrodynamic plasma waveguides generated in unclustered gases. Using femtosecond pump pulses, self-guided propagation and strong absorption (more than 70%) are used to produce long centimetre scale channels in an argon cluster jet, and a subsequent intense pulse is coupled into the guide with 50% efficiency and guided at above 10(17)W cm(-2) intensity over 40 Rayleigh lengths. We also demonstrate efficient generation of waveguides using 100 ps axicon-generated Bessel-beam pump pulses. Despite the expected sub-picosecond cluster disassembly time, we observe long pulse absorption efficiencies up to a maximum of 35%. Simulations show that in the far leading edge of the long laser pulse, the volume of heated clusters evolves to a locally uniform and cool plasma already near ionization saturation, which is then efficiently heated by the remainder of the pulse.
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Egiyan KS, Dashyan NB, Sargsian MM, Strikman MI, Weinstein LB, Adams G, Ambrozewicz P, Anghinolfi M, Asavapibhop B, Asryan G, Avakian H, Baghdasaryan H, Baillie N, Ball JP, Baltzell NA, Batourine V, Battaglieri M, Bedlinskiy I, Bektasoglu M, Bellis M, Benmouna N, Biselli AS, Bonner BE, Bouchigny S, Boiarinov S, Bradford R, Branford D, Brooks WK, Bültmann S, Burkert VD, Bultuceanu C, Calarco JR, Careccia SL, Carman DS, Carnahan B, Chen S, Cole PL, Coltharp P, Corvisiero P, Crabb D, Crannell H, Cummings JP, De Sanctis E, DeVita R, Degtyarenko PV, Denizli H, Dennis L, Dharmawardane KV, Djalali C, Dodge GE, Donnelly J, Doughty D, Dragovitsch P, Dugger M, Dytman S, Dzyubak OP, Egiyan H, Elouadrhiri L, Empl A, Eugenio P, Fatemi R, Fedotov G, Feuerbach RJ, Forest TA, Funsten H, Gavalian G, Gevorgyan NG, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz JT, Golovatch E, Gothe RW, Griffioen KA, Guidal M, Guillo M, Guler N, Guo L, Gyurjyan V, Hadjidakis C, Hardie J, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hu J, Huertas M, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Ito MM, Jenkins D, Jo HS, Joo K, Juengst HG, Kellie JD, Khandaker M, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klimenko A, Klusman M, Kramer LH, Kubarovsky V, Kuhn J, Kuhn SE, Kuleshov S, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Lee T, Livingston K, Maximon LC, McAleer S, McKinnon B, McNabb JWC, Mecking BA, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Morrow SA, Mueller J, Mutchler GS, Nadel-Turonski P, Napolitano J, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, O'Relly GV, Osipenko M, Ostrovidov AI, Park K, Pasyuk E, Peterson C, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rosner G, Rossi P, Rowntree D, Rubin PD, Sabatié F, Salgado C, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Shaw J, Smith ES, Smith LC, Sober DI, Stavinsky A, Stepanyan S, Stokes BE, Stoler P, Strauch S, Suleiman R, Taiuti M, Taylor S, Tedeschi DJ, Thompson R, Tkabladze A, Tkachenko S, Todor L, Tur C, Ungaro M, Vineyard MF, Vlassov AV, Weygand DP, Williams M, Wolin E, Wood MH, Yegneswaran A, Yun J, Zana L, Zhang J. Measurement of two- and three-nucleon short-range correlation probabilities in nuclei. PHYSICAL REVIEW LETTERS 2006; 96:082501. [PMID: 16606174 DOI: 10.1103/physrevlett.96.082501] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Indexed: 05/08/2023]
Abstract
The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured at 1 < xB <. At Q2 > 1.4 GeV2, the ratios exhibit two separate plateaus, at 1.5 < xB < 2 and at xB > 2.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A = 3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A = 4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei.
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Dugger M, Ball JP, Collins P, Pasyuk E, Ritchie BG, Adams G, Ambrozewicz P, Anciant E, Anghinolfi M, Asavapibhop B, Asryan G, Audit G, Avakian H, Bagdasaryan H, Baillie N, Baltzell NA, Barrow S, Batourine V, Battaglieri M, Beard K, Bedlinskiy I, Bektasoglu M, Bellis M, Benmouna N, Berman BL, Bianchi N, Biselli AS, Bonner BE, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Bültmann S, Burkert VD, Butuceanu C, Calarco JR, Careccia SL, Carman DS, Carnahan B, Chen S, Cole PL, Coleman A, Coltharp P, Cords D, Corvisiero P, Crabb D, Crannell H, Credé V, Cummings JP, De Sanctis E, DeVita R, Degtyarenko PV, Denizli H, Dennis L, Deur A, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Donnelly J, Doughty D, Dragovitsch P, Dytman S, Dzyubak OP, Egiyan H, Egiyan KS, Elouadrhiri L, Empl A, Eugenio P, Fatemi R, Fedotov G, Feldman G, Feuerbach RJ, Forest TA, Funsten H, Garçon M, Gavalian G, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz JT, Gothe RW, Griffioen KA, Guidal M, Guillo M, Guler N, Guo L, Gyurjyan V, Hadjidakis C, Hakobyan RS, Hardie J, Heddle D, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hu J, Huertas M, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Ito MM, Jenkins D, Jo HS, Joo K, Juengst HG, Kellie JD, Khandaker M, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klimenko AV, Klusman M, Kossov M, Kramer LH, Kubarovsky V, Kuhn J, Kuhn SE, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Lee T, Lima ACS, Livingston K, Lukashin K, Manak JJ, Marchand C, Maximon LC, McAleer S, McKinnon B, McNabb JWC, Mecking BA, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Morrow SA, Muccifora V, Mueller J, Mutchler GS, Nadel-Turonski P, Napolitano J, Nasseripour R, Niccolai S, Niculescu G, Niczyporuk BB, Niyazov RA, Nozar M, O'Rielly GV, Osipenko M, Ostrovidov AI, Park K, Paterson C, Philips SA, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ricco G, Ripani M, Ronchetti F, Rosner G, Rossi P, Rowntree D, Rubin PD, Sabatié F, Salgado C, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Simionatto S, Skabelin AV, Smith ES, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan SS, Stepanyan S, Stokes BE, Stoler P, Strakovsky II, Strauch S, Taiuti M, Taylor S, Tedeschi DJ, Thoma U, Thompson R, Tkabladze A, Tkachenko S, Tur C, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weller H, Weygand DP, Williams M, Wolin E, Wood MH, Yegneswaran A, Yun J, Zana L, Zhang J. Eta' photoproduction on the proton for photon energies from 1.527 to 2.227 GeV. PHYSICAL REVIEW LETTERS 2006; 96:062001. [PMID: 16605984 DOI: 10.1103/physrevlett.96.062001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Indexed: 05/08/2023]
Abstract
Differential cross sections for the reaction gamma p --> eta' p have been measured with the CLAS spectrometer and a tagged photon beam with energies from 1.527 to 2.227 GeV. The results reported here possess much greater accuracy than previous measurements. Analyses of these data suggest for the first time the coupling of the eta'N channel to both the S11(1535) and P11(1710) resonances, known to couple strongly to the etaN channel in photoproduction on the proton, and the importance of J = 3/2 resonances in the process.
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