The jet cross-section and jet-substructure observables in $p$$+$$p$
collisions at $\sqrt{s}=200$ GeV were measured by the PHENIX Collaboration at
the Relativistic Heavy Ion Collider (RHIC). Jets are ...reconstructed from
charged-particle tracks and electromagnetic-calorimeter clusters using the
anti-$k_{t}$ algorithm with a jet radius $R=0.3$ for jets with transverse
momentum within $8.0<p_T<40.0$ GeV/$c$ and pseudorapidity $|\eta|<0.15$.
Measurements include the jet cross section, as well as distributions of
SoftDrop-groomed momentum fraction ($z_g$), charged-particle transverse
momentum with respect to jet axis ($j_T$), and radial distributions of charged
particles within jets ($r$). Also meaureed was the distribution of
$\xi=-ln(z)$, where $z$ is the fraction of the jet momentum carried by the
charged particle. The measurements are compared to theoretical next-to and
next-to-next-to-leading-order calculatios, PYTHIA event generator, and to other
existing experimental results. Indicated from these meaurements is a lower
particle multiplicity in jets at RHIC energies when compared to models. Also
noted are implications for future jet measurements with sPHENIX at RHIC as well
as at the future Election-Ion Collider.
This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Hidekazu Tsukamoto and Yoshiyuki Takei. The presentations were (1) Tribute to ...Professor Rajendar K. Chawla, by Craig J. McClain; (2) Dysregulated TNF signaling in alcoholic liver disease, by Craig J. McClain, S. Joshi-Barve, D. Hill, J Schmidt, I. Deaciuc, and S. Barve; (3) The role of mitochondria in ethanol-mediated sensitization of the liver, by Anna Colell, Carmen Garcia-Ruiz, Neil Kaplowitz, and Jose C. Fernandez-Checa; (4) A peroxisome proliferator (bezafibrate) can prevent superoxide anion release into hepatic sinusoid after acute ethanol administration, by Hirokazu Yokoyama, Yukishige Okamura, Yuji Nakamura, and Hiromasa Ishii; (5) S-adenosylmethionine affects tumor necrosis factor-alpha gene expression in macrophages, by Rajendar K. Chawla, S. Barve, S. Joshi-Barve, W. Watson, W. Nelson, and C. McClain; (6) Iron, retinoic acid and hepatic macrophage TNFalpha gene expression in ALD, by Hidekazu Tsukamoto, Min Lin, Mitsuru Ohata, and Kenta Motomura; and (7) Role of Kupffer cells and gut-derived endotoxin in alcoholic liver injury, by N. Enomoto, K. Ikejima, T. Kitamura, H. Oide, Y. Takei, M. Hirose, B. U. Bradford, C. A. Rivera, H. Kono, S. Peter, S. Yamashina, A. Konno, M. Ishikawa, H. Shimizu, N. Sato, and R. Thurman.
Phys. Rev. C 109, 054910 (2024) The PHENIX experiment has performed a systematic study of identified
charged-hadron ($\pi^\pm$, $K^\pm$, $p$, $\bar{p}$) production at midrapidity
in $p$$+$Al, ...$^3$He$+$Au, Cu$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV and
U$+$U collisions at $\sqrt{s_{_{NN}}}=193$ GeV. Identified charged-hadron
invariant transverse-momentum ($p_T$) and transverse-mass ($m_T$) spectra are
presented and interpreted in terms of radially expanding thermalized systems.
The particle ratios of $K/\pi$ and $p/\pi$ have been measured in different
centrality ranges of large (Cu$+$Au, U$+$U) and small ($p$$+$Al, $^3$He$+$Au)
collision systems. The values of $K/\pi$ ratios measured in all considered
collision systems were found to be consistent with those measured in $p$$+$$p$
collisions. However the values of $p/\pi$ ratios measured in large collision
systems reach the values of $\approx0.6$, which is $\approx2$ times larger than
in $p$$+$$p$ collisions. These results can be qualitatively understood in terms
of the baryon enhancement expected from hadronization by recombination.
Identified charged-hadron nuclear-modification factors ($R_{AB}$) are also
presented. Enhancement of proton $R_{AB}$ values over meson $R_{AB}$ values was
observed in central $^3$He$+$Au, Cu$+$Au, and U$+$U collisions. The proton
$R_{AB}$ values measured in $p$$+$Al collision system were found to be
consistent with $R_{AB}$ values of $\phi$, $\pi^\pm$, $K^\pm$, and $\pi^0$
mesons, which may indicate that the size of the system produced in $p$$+$Al
collisions is too small for recombination to cause a noticeable increase in
proton production.
Limited data exist regarding morphogenesis and differentiation during liver regeneration. We examined the role of epimorphin on liver regeneration. After 70% partial hepatectomy, mouse liver was ...collected on days 1, 3, 7, and 14 for immunohistochemistry and the detection of epimorphin mRNA and connexin 32. Using primary cultured rat hepatocytes, morphogenesis and differentiation of cells were tested with or without epimorphin. Seven days after cell inoculation, the expression of connexin 32 and the cell–cell communication was tested as a marker of differentiation. Epimorphin was detected exclusively in hepatic stellate cells. Connexin 32 was detected only in hepatocytes. After partial hepatectomy, epimorphin mRNA was detected on day 3 and peaked at day 7, followed by protein expression. Connexin 32 expression showed a similar time course. Cultured hepatocytes formed multicellular spheroids in an active epimorphin-coated culture dish and showed positive dye coupling, whereas the cell–cell communication was lost without active epimorphin. Because epimorphin was expressed late in liver regeneration, it might play a role in morphogenesis and differentiation.
We previously reported stellate (Ito) cells possess voltage-activated Ca
2+ current. The activation of stellate cells has been indicated to contribute to liver fibrosis and the regulation of hepatic ...hemodynamics. The aim of this study was to investigate the relationship between voltage-activated Ca
2+ current and activation of stellate cells. Voltage-activated Ca
2+ current in stellate cells isolated from rats were studied using whole-cell patch clamp technique. L-type voltage-activated Ca
2+ current was hardly detected in stellate cells cultured for less than 9 days. Ca
2+ current was detected 12.5 and 69% of cells at the 10th and 14th day of culture, respectively. BrdU incorporation indicated cell proliferation was recognized over 50% of cells at the 3rd and 5th day of culture, respectively, then decreased significantly in a time-dependent manner. On the other hand, the expression of α-smooth muscle actin indicated cell activation increased from 7th day of culture and collagen type I mRNA appeared remarkably in cells cultured for more than 10 days. In this study, we concluded L-type voltage-activated Ca
2+ current was recognized in activated stellate (myofibroblast-like) cells.
A neutron decays into a proton, an electron, and an anti-neutrino through the beta-decay process. The decay lifetime (\(\sim\)880 s) is an important parameter in the weak interaction. For example, ...the neutron lifetime is a parameter used to determine the |\(V_{\rm ud}\)| parameter of the CKM quark mixing matrix. The lifetime is also one of the input parameters for the Big Bang Nucleosynthesis, which predicts light element synthesis in the early universe. However, experimental measurements of the neutron lifetime today are significantly different (8.4 s or 4.0\(\sigma\)) depending on the methods. One is a bottle method measuring surviving neutron in the neutron storage bottle. The other is a beam method measuring neutron beam flux and neutron decay rate in the detector. There is a discussion that the discrepancy comes from unconsidered systematic error or undetectable decay mode, such as dark decay. A new type of beam experiment is performed at the BL05 MLF J-PARC. This experiment measured neutron flux and decay rate simultaneously with a time projection chamber using a pulsed neutron beam. We will present the world situation of neutron lifetime and the latest results at J-PARC.
Background: Ethanol causes both tolerance and sensitization of Kupffer cells. Accordingly, this study examines the effect of acute ethanol consumption on nitric oxide (NO) production from Kupffer ...cells with or without lipopolysaccharide (LPS) treatment.
Methods: Rats were given ethanol (4 g/kg body weight) intragastrically, and Kupffer cells were isolated 2 and 24 hr later. Some rats were treated for 4 days with 150 mg/kg/day of polymyxin B and 450 mg/kg/day of neomycin to prevent growth of intestinal bacteria, the primary source of endotoxin in the gastrointestinal tract. After addition of LPS, NO was measured by the Griess reaction.
Results: Two hours after ethanol administration, LPS‐induced NO production by Kupffer cells was diminished by 50% but was enhanced 2‐fold at 24 hr. Sterilization of the gut with antibiotics blocked this enhancement.
Conclusions: Kupffer cells isolated from rats early after ethanol exhibited tolerance to LPS, whereas sensitization was observed later. It is likely that sensitization to Kupffer cell is caused by gut‐derived endotoxin.
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