7,172 research outputs found

    Measurement of π\pi, K, p transverse momentum spectra with ALICE in proton-proton collisions at s=\sqrt{s} = 0.9 and 7 TeV

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    Results of the measurement of the π\pi, K, p transverse momentum (ptp_{\mathrm{t}}) spectra at mid-rapidity in proton-proton collisions at s=7\sqrt{s} = 7 TeV are presented. Particle identification was performed using the energy loss signal in the Inner Tracking System (ITS) and the Time Projection Chamber (TPC), while information from the Time-of-Flight (TOF) detector was used to identify particles at higher transverse momentum. From the spectra at s=7\sqrt{s} = 7 TeV the mean transverse momentum () and particle ratios were extracted and compared to results obtained for collisions at s=0.9\sqrt{s} = 0.9 TeV and lower energies.Comment: Quark Matter 2011 proceeding

    "Dry-column" chromatography of plant pigments

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    Separation of plant pigments which can be accomplished on thin-layer silica plates with mixture of petroleum ether, halocarbon, acetone, and polar solvent can be readily translated into dry-column technique that yields reproducible chromatograms after elution in fashion of liquid chromatography with fluorimeter as detector. Best solvent system was found to be mixture of petroleum ether, dichloromethane, acetone, and ethyl acetate

    Modification of cell vulnerability to oxidative stress by N-(3-oxododecanoyl)-L-homoserine-lactone, a quorum sensing molecule, in rat thymocytes

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    N-(3-oxododecanoyl)-L-homoserine-lactone (ODHL), a quorum sensing molecule, affects intracellular Zn2+ concentration ([Zn2+]i) and cellular levels of nonprotein thiols ([NPT]i) of rat thymic lymphocytes, both of which are assumed to affect cell vulnerability to oxidative stress. Therefore, it is interesting to examine the effects of ODHL on the cells under oxidative stress. ODHL augmented the cytotoxicity of H2O2, but not calcium ionophore A23187. ODHL potentiated the H2O2-induced elevation of [Zn2+]i, wherein, it greatly attenuated the H2O2-induced increase in intracellular Ca2+ concentration. ODHL did not affect [NPT]i in the presence of H2O2. Therefore, we conclude that the elevation of [Zn2+]i is involved in the ODHL-induced potentiation of H2O2 cytotoxicity. Our findings suggest that ODHL modifies cell vulnerability to oxidative stress in host cells

    Ziram, a dithiocarbamate fungicide, exhibits pseudo-cytoprotective actions against oxidative stress in rat thymocytes : Possible environmental risks

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    Ziram, a dithiocarbamate fungicide, protects various vegetables and fruits against infections by fungus. Recently, there have been increasing anxieties about the risks in the use of dithiocarbamate fungicides. Our previous studies showed that Zn2+ was a determinant of Ziram cytotoxicity. In addition, Zn2+ is linked to H2O2 cytotoxicity. Therefore, in this study, we aimed to test the hypothesis that Ziram could augment the cytotoxicity of H2O2 by examining the changes induced by Ziram in some cellular parameters in rat thymic lymphocytes subjected to H2O2-induced oxidative stress using flow-cytometric methods with fluorescent dyes. Ziram significantly attenuated H2O2-induced cell death at sublethal concentrations. However, in the cells under oxidative stress elicited by H2O2, Ziram promoted the changing over from intact cells to living cells with exposed phosphatidylserine (PS) on plasma membranes, whereas it inhibited the transition from PS-exposed living cells to dead cells. Ziram significantly augmented H2O2 actions, including reduction of cellular glutathione levels and elevation of intracellular Zn2+ concentrations. Conversely, it attenuated H2O2-induced depolarization of mitochondrial membrane potential. Ziram at sublethal concentrations seems to exhibit promotive and suppressive actions on the process of cell death caused by H2O2. Ziram increased the number of living cells with exposed PS, a phenomenon characteristic of early stages of apoptosis. Thus, it is concluded that Ziram exhibits pseudo-cytoprotective actions against H2O2- induced oxidative stress

    Oscillation Phenomena in the disk around the massive black hole Sagittarius A*

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    We report the detection of radio QPOs with structure changes using the Very Long Baseline Array (VLBA) at 43 GHz. We found conspicuous patterned changes of the structure with P = 16.8 +- 1.4, 22.2 +- 1.4, 31.2 +- 1.5, 56.4 +- 6 min, very roughly in a 3:4:6:10 ratio. The first two periods show a rotating one-arm structure, while the P = 31.4 min shows a rotating 3-arm structure, as if viewed edge-on. At the central 50 microasec the P = 56.4 min period shows a double amplitude variation of those in its surroundings. Spatial distributions of the oscillation periods suggest that the disk of SgrA* is roughly edge-on, rotating around an axis with PA = -10 degree. Presumably, the observed VLBI images of SgrA* at 43 GHz retain several features of the black hole accretion disk of SgrA* in spite of being obscured and broadened by scattering of surrounding plasma.Comment: 24 pages, 20 figures, revised version submitted to MN main journal (2010, Jan., 12th

    A Measurement of Proper Motions of SiO Maser Sources in the Galactic Center with the VLBA

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    We report on the high-precision astrometric observations of maser sources around the Galactic Center in the SiO J=1--0 v=1 and 2 lines with the VLBA during 2001 -- 2004. With phase-referencing interferometry referred to the radio continuum source Sgr A*, accurate positions of masers were obtained for three detected objects: IRS 10 EE (7 epochs), IRS 15NE (2 epochs), and SiO 6 (only 1 epoch). Because circumstellar masers of these objects were resolved into several components, proper motions for the maser sources were derived with several different methods. Combining our VLBA results with those of the previous VLA observations, we obtained the IRS 10EE proper motion of 76+-3 km s^{-1} (at 8 kpc) to the south relative to Sgr A*. Almost null proper motion of this star in the east--west direction results in a net transverse motion of the infrared reference frame of about 30+-9 km s^{-1} to the west relative to Sgr A*. The proper-motion data also suggests that IRS 10EE is an astrometric binary with an unseen massive companion.Comment: High-res. figures are available at ftp://ftp.nro.nao.ac.jp/nroreport/no656.pdf.gz . PASJ 60, No. 1 (2008) in pres

    Diffraction dissociation in proton-proton collisions at s\sqrt{s} = 0.9 TeV, 2.76 TeV and 7 TeV with ALICE at the LHC

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    The relative rates of single- and double- diffractive processes were measured with the ALICE detector by studying properties of gaps in the pseudorapidity distribution of particles produced in proton-proton collisions at s\sqrt{s} = 0.9 TeV, 2.76 TeV and 7 TeV. ALICE triggering efficiencies are determined for various classes of events, using a detector simulation validated with data on inclusive particle production. Cross-sections are determined using van der Meer scans to measure beam properties and obtain a measurement of the luminosity

    Differentiation of Cardiac from Noncardiac Pleural Effusions in Cats using Second-Generation Quantitative and Point-of-Care NT-proBNP Measurements

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    BACKGROUND: Pleural effusion is a common cause of dyspnea in cats. N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) measurement, using a first‐generation quantitative ELISA, in plasma and pleural fluid differentiates cardiac from noncardiac causes of pleural effusion. HYPOTHESIS/OBJECTIVES: To determine whether NT‐proBNP measurements using second‐generation quantitative ELISA and point‐of‐care (POC) tests in plasma and pleural fluid distinguish cardiac from noncardiac pleural effusions and how results compare to the first‐generation ELISA. ANIMALS: Thirty‐eight cats (US cohort) and 40 cats (UK cohort) presenting with cardiogenic or noncardiogenic pleural effusion. METHODS: Prospective cohort study. Twenty‐one and 17 cats in the US cohort, and 22 and 18 cats in the UK cohort were classified as having cardiac or noncardiac pleural effusion, respectively. NT‐proBNP concentrations in paired plasma and pleural fluid samples were measured using second‐generation ELISA and POC assays. RESULTS: The second‐generation ELISA differentiated cardiac from noncardiac pleural effusion with good diagnostic accuracy (plasma: sensitivity, 95.2%, specificity, 82.4%; pleural fluid: sensitivity, 100%, specificity, 76.5%). NT‐proBNP concentrations were greater in pleural fluid (719 pmol/L (134–1500)) than plasma (678 pmol/L (61–1500), P = 0.003), resulting in different cut‐off values depending on the sample type. The POC test had good sensitivity (95.2%) and specificity (87.5%) when using plasma samples. In pleural fluid samples, the POC test had good sensitivity (100%) but low specificity (64.7%). Diagnostic accuracy was similar between first‐ and second‐generation ELISA assays. CONCLUSIONS AND CLINICAL IMPORTANCE: Measurement of NT‐proBNP using a quantitative ELISA in plasma and pleural fluid or POC test in plasma, but not pleural fluid, distinguishes cardiac from noncardiac causes of pleural effusion in cats
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