1,130 research outputs found

    Electric foot-shock stress drives TNF-alpha production in the liver of IL-6-deficient mice

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    Objectives: Accumulating evidence has shown that interleukin-6 (IL-6) has pleiotropic effects on a variety of biological functions, including its antiapoptotic potential during liver injury. Our previous work demonstrated that restraint stress-induced elevation of plasma IL-6 negatively regulates plasma tumor necrosis factor-alpha (TNF-alpha). Herein, we further clarified the mechanism underlying the above finding and investigated the effect of IL-6 on liver apoptosis triggered by stress. Methods: Male C57BL/6J and IL-6-deficient C57BL/SV129 mice were exposed to 1 h of electric foot-shock stress. Thereafter, the serum, liver and spleen TNF-alpha levels were measured at several time points. Serum alanine aminotransferase (ALT), liver caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling ( TUNEL) activities were analyzed to evaluate the severity of liver injury and apoptosis. Results: The liver, but not the spleen, of the IL-6-deficient mice exhibited a significant increase in TNF-alpha level after stress in parallel with serum TNF-alpha elevation, whereas no such TNF-alpha responses were found in the wild animals. No significant differences in stress-induced elevation of serum ALT levels, liver caspase-3 activities and the number of TUNEL-positive hepatocytes were found between the wild and IL-6-deficient mice. Conclusions: Taken together, these results indicate that IL-6 may play a critical role in suppressing TNF-alpha production in the liver, thereby decreasing the blood TNF-alpha level. In contrast, IL-6 secretion was shown to have no protective effect on stress-triggered liver injury. Copyright (C) 2004 S. Karger AG, Basel

    Photoelectron Angular Distributions for Two-photon Ionization of Helium by Ultrashort Extreme Ultraviolet Free Electron Laser Pulses

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    Phase-shift differences and amplitude ratios of the outgoing ss and dd continuum wave packets generated by two-photon ionization of helium atoms are determined from the photoelectron angular distributions obtained using velocity map imaging. Helium atoms are ionized with ultrashort extreme-ultraviolet free-electron laser pulses with a photon energy of 20.3, 21.3, 23.0, and 24.3 eV, produced by the SPring-8 Compact SASE Source test accelerator. The measured values of the phase-shift differences are distinct from scattering phase-shift differences when the photon energy is tuned to an excited level or Rydberg manifold. The difference stems from the competition between resonant and non-resonant paths in two-photon ionization by ultrashort pulses. Since the competition can be controlled in principle by the pulse shape, the present results illustrate a new way to tailor the continuum wave packet.Comment: 5 pages, 1 table, 3 figure

    Effects of cAMP on the composition of berry juice in Muscat Bailey A

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    In Muscat Bailey A, the increases of organic acids due to cAMP prebloom application 3 weeks before final harvest were accompanied by increases of glucose and fructose, though these increments compared with control diminished toward full maturity. Der Einfluß von cyclischem Adenosin-3' ,5' -monophosphat auf die Zusammensetzung des Beerensaftes bei Muscat Bailey A Wurden die Infloreszenzen der Rebsorte Muscat Bailey A (Vitis labrusca L. x V. vinifera L.) vor der Blüte mit cAMP behandelt, so war 3 Wochen vor der vollen Reife ein Anstieg des Säuregehaltes und ebenso der Glucose- und Fructosekonzentration zu verzeichnen; gegen Ende der Reifephase waren die Unterschiede im Glucose- und Fructosegehalt behandelter und unbehandelter Beeren allerdings ziemlich verwischt

    Increase of the acid contents in grape berries by treatment with cAMP

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    cAMP prebloom application to flower clusters of the grapevine variety Delaware (Vitis labruscana BAILEY) raised the content of organic acids in the repening berries. The total content of amino acids in the juice was raised by postbloom application, alanine, arginine and γ-aminobutyric acid being increased, whereas tyrosine was decreased. Zunahme des Säuregehaltes reifender Traubenbeeren durch Behandlung mit cyclischemAdenosin-3',5' -monophosphat Bei der Rebsorte Delaware wurde durch Behandlung der Infloreszenzen mit cAMP vor der Blüte der Gehalt des Beerensaftes an organischen Säuren erhöht.Durch cAMP-Behandlung nach der Blüte wurde der Gesamtgehalt der Aminosäuren gesteigert, wobei Alanin, Arginin und γ-Aminobuttersäure zunahmen, während die Tyrosinkonzentration verringert war. &nbsp

    Ultrafast Dynamics of a Nucleobase Analogue Illuminated by a Short Intense X-ray Free Electron Laser Pulse

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    Citation: Nagaya, K., Motomura, K., Kukk, E., Fukuzawa, H., Wada, S., Tachibana, T., . . . Ueda, K. (2016). Ultrafast Dynamics of a Nucleobase Analogue Illuminated by a Short Intense X-ray Free Electron Laser Pulse. Physical Review X, 6(2), 9. doi:10.1103/PhysRevX.6.021035Understanding x-ray radiation damage is a crucial issue for both medical applications of x rays and x-ray free-electron-laser (XFEL) science aimed at molecular imaging. Decrypting the charge and fragmentation dynamics of nucleobases, the smallest units of a macro-biomolecule, contributes to a bottom-up understanding of the damage via cascades of phenomena following x-ray exposure. We investigate experimentally and by numerical simulations the ultrafast radiation damage induced on a nucleobase analogue (5-iodouracil) by an ultrashort (10 fs) high-intensity radiation pulse generated by XFEL at SPring-8 Angstrom Compact free electron Laser (SACLA). The present study elucidates a plausible underlying radiosensitizing mechanism of 5-iodouracil. This mechanism is independent of the exact composition of 5-iodouracil and thus relevant to other such radiosensitizers. Furthermore, we found that despite a rapid increase of the net molecular charge in the presence of iodine, and of the ultrafast release of hydrogen, the other atoms are almost frozen within the 10-fs duration of the exposure. This validates single-shot molecular imaging as a consistent approach, provided the radiation pulse used is brief enough

    OGLE-2005-BLG-153: Microlensing Discovery and Characterization of A Very Low Mass Binary

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    The mass function and statistics of binaries provide important diagnostics of the star formation process. Despite this importance, the mass function at low masses remains poorly known due to observational difficulties caused by the faintness of the objects. Here we report the microlensing discovery and characterization of a binary lens composed of very low-mass stars just above the hydrogen-burning limit. From the combined measurements of the Einstein radius and microlens parallax, we measure the masses of the binary components of 0.10±0.01 M0.10\pm 0.01\ M_\odot and 0.09±0.01 M0.09\pm 0.01\ M_\odot. This discovery demonstrates that microlensing will provide a method to measure the mass function of all Galactic populations of very low mass binaries that is independent of the biases caused by the luminosity of the population.Comment: 6 pages, 3 figures, 1 tabl

    OGLE-2005-BLG-071Lb, the Most Massive M-Dwarf Planetary Companion?

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    We combine all available information to constrain the nature of OGLE-2005-BLG-071Lb, the second planet discovered by microlensing and the first in a high-magnification event. These include photometric and astrometric measurements from Hubble Space Telescope, as well as constraints from higher order effects extracted from the ground-based light curve, such as microlens parallax, planetary orbital motion and finite-source effects. Our primary analysis leads to the conclusion that the host of Jovian planet OGLE-2005-BLG-071Lb is an M dwarf in the foreground disk with mass M= 0.46 +/- 0.04 Msun, distance D_l = 3.3 +/- 0.4 kpc, and thick-disk kinematics v_LSR ~ 103 km/s. From the best-fit model, the planet has mass M_p = 3.8 +/- 0.4 M_Jup, lies at a projected separation r_perp = 3.6 +/- 0.2 AU from its host and so has an equilibrium temperature of T ~ 55 K, i.e., similar to Neptune. A degenerate model less favored by \Delta\chi^2 = 2.1 (or 2.2, depending on the sign of the impact parameter) gives similar planetary mass M_p = 3.4 +/- 0.4 M_Jup with a smaller projected separation, r_\perp = 2.1 +/- 0.1 AU, and higher equilibrium temperature T ~ 71 K. These results from the primary analysis suggest that OGLE-2005-BLG-071Lb is likely to be the most massive planet yet discovered that is hosted by an M dwarf. However, the formation of such high-mass planetary companions in the outer regions of M-dwarf planetary systems is predicted to be unlikely within the core-accretion scenario. There are a number of caveats to this primary analysis, which assumes (based on real but limited evidence) that the unlensed light coincident with the source is actually due to the lens, that is, the planetary host. However, these caveats could mostly be resolved by a single astrometric measurement a few years after the event.Comment: 51 pages, 12 figures, 3 tables, Published in Ap

    Enhanced Nogo-P3 amplitudes of mothers compared with non-mother women during an emotional Go/Nogo task

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    Background: It is known that emotion regulatory responses of humans are changed by the experiences they have, but in particular, they are changed by becoming a mother. A recent study has found how a woman's emotion regulatory response to a child's crying changes after becoming a mother. However, mothers' emotion regulatory responses other than those to children and the association between emotion regulatory response and parental stress are still unknown. Methods: Eighteen healthy Japanese females (nine mothers and nine non-mothers) participated in the experiment. They performed an emotional Go/Nogo task, with facial expressions of others (angry, happy, and neutral faces) used as emotional stimuli. The percentage of correct responses, response time, and event-related potentials (ERPs) during the task was measured. Results: This comparison revealed that the mother group had a larger P3 (Nogo-P3) amplitude than the non-mother group when Nogo trials were held. This indicates that in mothers, there was greater activation of the behavioral inhibition-related brain areas than in non-mother women when they inhibited inappropriate behavior following recognition of facial expressions of others. In addition, in the mother group, there was a negative correlation between parental stress levels and Nogo-P3 amplitudes evoked by angry faces. This suggests that there is a relation between the level of parental stress of mothers and their emotion regulatory responses to angry faces. Conclusions: Our results demonstrate that mothers' emotion regulatory processes may differ from those of non-mothers in response, not only to a child's crying but also to expressions of emotions by others, and also suggest that the inhibitory recognition activity of mothers can be affected by parental stres

    Two-photon resonant excitation of interatomic coulombic decay in neon dimers

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    The recent availability of intense and ultrashort extreme ultraviolet sources opens up the possibility of investigating ultrafast electronic relaxation processes in matter in an unprecedented regime. In this work we report on the observation of two-photon excitation of interatomic Coulombic decay (ICD) in neon dimers using the tunable intense pulses delivered by the free electron laser FERMI. The unique characteristics of FERMI (narrow bandwidth, spectral stability, and tunability) allow one to resonantly excite specific ionization pathways and to observe a clear signature of the ICD mechanism in the ratio of the ion yield created by Coulomb explosion. The present experimental results are explained by ab initio electronic structure and nuclear dynamics calculations
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