33 research outputs found
Skyrmions with holography and hidden local symmetry
We study baryons as Skyrmions in holographic QCD with D4/D8/D8-bar multi-D
brane system in type IIA superstring theory, and also in the non-linear sigma
model with hidden local symmetry (HLS). Comparing these two models, we find
that the extra-dimension and its nontrivial curvature can largely change the
role of (axial) vector mesons for baryons in four-dimensional space-time. In
the HLS approach, the rho-meson field as a massive Yang-Mills field has a
singular configuration in Skyrmion, which gives a strong repulsion for the
baryon as a stabilizer. When a_1 meson is added in this approach, the stability
of Skyrmion is lost by the cancellation of rho and a_1 contributions. On the
contrary, in holographic QCD, the rho-meson field does not appear as a massive
Yang-Mills field due to the extra-dimension and its nontrivial curvature. We
show that the rho-meson field has a regular configuration in Skyrmion, which
gives a weak attraction for the baryon in holographic QCD. We argue that
Skyrmion with pi, rho and a_1 mesons become stable due to the curved
extra-dimension and also the presence of the Skyrme term in holographic QCD.
From this result, we also discuss the features of our truncated-resonance
analysis on baryon properties with pi and rho mesons below the cutoff scale
M_KK about 1GeV in holographic QCD, which is compared with other 5D instanton
analysis.Comment: 7 pages, 7 figure
Metastatic Patterns of Myxoid/Round Cell Liposarcoma: A Review of a 25-Year Experience
Myxoid/round cell liposarcoma (MRCL), unlike other soft tissue sarcomas, has been associated with unusual pattern of metastasis to extrapulmonary sites. In an attempt to elucidate the clinical features of MRCL with metastatic lesions, 58 cases, from the medical database of Keio University Hospital were used for the evaluation. 47 patients (81%) had no metastases, whereas 11 patients (11%) had metastases during their clinical course. Among the 11 patients with metastatic lesions, 8 patients (73%) had extrapulmonary metastases and 3 patients (27%) had pulmonary metastases. Patients were further divided into three groups; without metastasis, with extrapulmonary metastasis, and with pulmonary metastasis. When the metastatic patterns were stratified according to tumor size, there was statistical significance between the three groups (P = 0.028). The 8 cases with extrapulmonary metastases were all larger than 10 cm. Similarly, histological grading had a significant impact on metastatic patterns (P = 0.027). 3 cases with pulmonary metastatic lesions were all diagnosed as high grade. In conclusion, large size and low histological grade were significantly associated with extrapulmonary metastasis