3,608 research outputs found
A Note on Asymptotic Freedom at High Temperatures
This short note considers, within the external field approach outlined in
hep-ph/0202026, the role of the lowest lying gluon Landau mode in QCD in the
high temperature limit. Its influence on a temperature- and field-dependent
running coupling constant is examined. The thermal imaginary part of the mode
is temperature-independent in our approach and exactly cancels the well-known
zero temperature imaginary part, thus rendering the Savvidy vacuum stable.
Combining the real part of the mode with the contributions from the higher
lying Landau modes and the vacuum contribution, a field-independent coupling
alpha_s(T) is obtained. It can be interpreted as the ordinary zero temperature
running coupling constant with average thermal momenta \approx 2pi T for
gluons and \approx pi T for quarks.Comment: 4 pages; minor changes, version to appear in Phys. Rev.
Glycosylation pattern of brush border-associated glycoproteins in enterocyte-like cells: involvement of complex-type N-glycans in apical trafficking
We have previously reported that galectin-4, a tandem repeat-type galectin, regulates the raft-dependent delivery of glycoproteins to the apical brush border membrane of enterocyte-like HT-29 cells. N-Acetyllactosamine-containing glycans, known as galectin ligands, were found enriched in detergent-resistant membranes. Here, we analyzed the potential contribution of N-and/ or O-glycans in this mechanism. Structural studies were carried out on the brush border membrane-enriched fraction using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and nano-ESI-QTOF-MS/MS. The pattern of N-glycans was very heterogeneous, with the presence of high mannose- and hybrid-type glycans as well as a multitude of complex-type glycans. In contrast, the pattern of O-glycans was very simple with the presence of two major core type 1 O-glycans, sialylated and bisialylated T-antigen structures {[}Neu5Ac alpha 2-3Gal beta 1-3GalNAc-ol and Neu5Ac alpha 2-3Gal beta 1 -3(Neu5Ac alpha 2-6)GalNAc-ol]. Thus, N-glycans rather than O-glycans contain the N-acetyllactosamine recognition signals for the lipid raft-based galectin-4-dependent apical delivery. In the presence of 1-deoxymannojirimycin, a drug which inhibits the generation of hybrid-type or complex type N-glycans, the extensively O-glycosylated mucin-like MUC1 glycoprotein was not delivered to the apical brush border but accumulated inside the cells. Altogether, our data demonstrate the crucial role of complex N-glycans in the galectin-4-dependent delivery of glycoproteins to the apical brush border membrane of enterocytic HT-29 cells
Chromomagnetism in nuclear matter
Quarks are color charged particles. Due to their motion there is a strong
possibility of generation of color magnetic field. It is shown that however
hadrons are color singlet particles they may have non-zero color magnetic
moment. Due to this color magnetic moment hadrons can show color interaction.
In this paper we have studied the chromomagnetic properties of nuclear matter.Comment: 6 pages, 1 figure, accepted for publication in Int. J. Theor. Phy
"Cold Melting" of Invar Alloys
An anomalously strong volume magnetostriction in Invars may lead to a
situation when at low temperatures the dislocation free energy becomes negative
and a multiple generation of dislocations becomes possible. This generation
induces a first order phase transition from the FCC crystalline to an amorphous
state, and may be called "cold melting". The possibility of the cold melting in
Invars is connected with the fact that the exchange energy contribution into
the dislocation self energy in Invars is strongly enhanced, as compared to
conventional ferromagnetics, due to anomalously strong volume magnetostriction.
The possible candidate, where this effect can be observed, is a FePt disordered
Invar alloy in which the volume magnetostriction is especially large
Orbital and spin interplay in spin-gap formation in pyroxene titanium oxides ATiSi2O6 (A=Na, Li)
Interplay between orbital and spin degrees of freedom is theoretically
studied for the phase transition to the spin-singlet state with lattice
dimerization in pyroxene titanium oxides ATiSi2O6 (A=Na, Li). For the quasi
one-dimensional spin-1/2 systems, we derive an effective spin-orbital-lattice
coupled model in the strong correlation limit with explicitly taking account of
the t_2g orbital degeneracy, and investigate the model by numerical simulation
as well as the mean-field analysis. We find a nontrivial feedback effect
between orbital and spin degrees of freedom; as temperature decreases,
development of antiferromagnetic spin correlations changes the sign of orbital
correlations from antiferro to ferro type, and finally the ferro-type orbital
correlations induce the dimerization and the spin-singlet formation. As a
result of this interplay, the system undergoes a finite-temperature transition
to the spin-dimer and orbital-ferro ordered phase concomitant with the
Jahn-Teller lattice distortion. The numerical results for the magnetic
susceptibility show a deviation from the Curie-Weiss behavior, and well
reproduce the experimental data. The results reveal that the Jahn-Teller energy
scale is considerably small and the orbital and spin exchange interactions play
a decisive role in the pyroxene titanium oxides.Comment: 13 pages, 9 figures; final version. Text, Fig.1, and references are
revised. To appear in Phys. Rev.
Homo-chiral crystal growth and mono-chiral helimagnetism in inorganic chiral magnetic compounds
Trabajo presentado al International Workshop on Multipole Physics and Related Phenomena (J-Physics), celebrado en Hachimantai, Iwate (Japón) del 24 al 28 de septiembThis work was supported by JSPS KAKENHI Grant Number 25220803, 25390139, 26108719, 15H03680, 15H05885, 15H05886, 16KK0102, 17H02912, 17H02767, and 17H02815. JC acknowledges the Grant Number MAT2015-68200-C2-2-P from the Spanish Ministry of Economy and Competitiveness.Peer Reviewe
Efficacy of conversion gastrectomy following docetaxel, cisplatin, and S-1 therapy in potentially resectable stage IV gastric cancer
AbstractBackgroundRecent advances in gastric cancer chemotherapy have made macroscopic complete resection possible in some patients with stage IV disease.MethodsWe retrospectively investigated the efficacy of multimodal therapy with combined docetaxel, cisplatin, and S-1 (DCS) and conversion gastrectomy in 57 patients with stage IV gastric cancer.ResultsOf the 57 patients, 15 patients were categorized into potentially resectable case, which is defined as patients with single incurable factor including the upper abdominal para-aortic lymph node metastasis (16a2b1 PAN metastasis) or fewer than three peripheral liver metastases. The other 42 were categorized as initially unresectable. All of patients underwent DCS therapy, and then 34 patients underwent conversion gastrectomy. The 3-year overall survival (OS) rate among the patients who underwent conversion gastrectomy was 50.1% with MST of 29.9 months. They had significantly longer OS than patients who underwent DCS therapy alone (p < 0.01). Univariate analysis among the patents with conversion gastrectomy identified 16a2b1PAN metastasis, peritoneal metastasis, potential resectable case, R0 resection as significant prognostic factors. A 3-year OS in potential resectable cases was 92.9%. Multivariate analysis identified potential resectability as the only independent prognostic factor contributing to OS (HR 0.133, 95%CI 0.024-0. 744, p = 0.021). In contrast, clinical response was selected as the only independent prognostic factor in the subgroup of initially unresectable cases (HR 0.354, 95%CI 0.151-0.783, p = 0.021).ConclusionPatients with potentially resectable disease had a remarkably good prognosis among stage IV gastric cancer patients, and might be ideal candidates for conversion gastrectomy following DCS therapy
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