4,992 research outputs found
Topological magnons in one-dimensional ferromagnetic Su-Schrieffer-Heeger model with anisotropic interaction
Topological magnons in a one-dimensional (1D) ferromagnetic (FM)
Su-Schrieffer-Heeger (SSH) model with anisotropic exchange interactions are
investigated. Apart from the inter-cellular isotropic Heisenberg interaction,
the intercellular anisotropic exchange interactions, i.e. Dzyaloshinskii-Moriya
interaction (DMI) and pseudo-dipolar interaction (PDI), also can induce the
emergence of the non-trivial phase with two degenerate in-gap edge states
separately localized at the two ends of the 1D chain, while the intracellular
interactions instead unfavors the topological phase. The interplay among them
has synergistic effects on the topological phase transition, very different
from that in the two-dimensional (2D) ferromagnet. These results demonstrate
that the 1D magnons possess rich topological phase diagrams distinctly
different from the electronic version of the SSH model and even the 2D magnons.
Due to the lower dimensional structural characteristics of this 1D topological
magnonic system, the magnonic crystals can be constructed from bottom to top,
which has important potential applications in the design of novel magnonic
devices.Comment: 22 pages, 11 figure
Serum soluble ST2 is associated with ER-positive breast cancer
BACKGROUND: ST2, a member of the interleukin (IL)-1receptor family, regulates Th1/Th2 immune responses in autoimmune and inflammatory conditions. However, the role of ST2 signaling in tumor growth and metastasis of breast cancers has not been investigated. This study investigated the possible role of soluble ST2 (sST2) in breast cancer. METHODS: The serum levels of IL-33, sST2, and vascular endothelial growth factor (VEGF) in 150 breast cancer patients and 90 healthy women were measured by enzyme-linked immunosorbent assay. Estrogen receptor(ER), progesterone receptor, human epithelial receptor (HER)-2, and cell cycle regulated protein Ki-67 were measured. Clinical stage, tumor size, lymph node metastasis, and histological type were also recorded. RESULTS: The serum levels of sST2, IL-33, and VEGF were significantly higher in breast cancer patients than in the control group (P < 0.05, each). Serum sST2 levels in ER-positive breast cancer patients were significantly associated with age, histological type, clinical stage, tumor size, and Ki-67 status (P < 0.05, each). Moreover, the serum levels of IL-33 and sST2 in breast cancers significantly correlated with VEGF levels (IL-33: r = 0.375, P < 0.0001; sST2: r = 0.164, P = 0.045). Serum levels of sST2, IL-33, and VEGF decreased after modified radical mastectomy in ER-positive breast cancers. Serum levels of IL-33, sST2, and VEGF and clinicopathological factors were not significantly correlated with disease-free survival and overall survival of ER-positive breast cancer women during follow-up. CONCLUSION: Serum sST2 levels in ER-positive breast cancer patients are significantly associated with factors that indicate poor prognosis
Physical properties and chemical composition of the cores in the California molecular cloud
We aim to reveal the physical properties and chemical composition of the
cores in the California molecular cloud (CMC), so as to better understand the
initial conditions of star formation. We made a high-resolution column density
map (18.2") with Herschel data, and extracted a complete sample of the cores in
the CMC with the \textsl{fellwalker} algorithm. We performed new
single-pointing observations of molecular lines near 90 GHz with the IRAM 30m
telescope along the main filament of the CMC. In addition, we also performed a
numerical modeling of chemical evolution for the cores under the physical
conditions. We extracted 300 cores, of which 33 are protostellar and 267 are
starless cores. About 51\% (137 of 267) of the starless cores are prestellar
cores. Three cores have the potential to evolve into high-mass stars. The
prestellar core mass function (CMF) can be well fit by a log-normal form. The
high-mass end of the prestellar CMF shows a power-law form with an index
that is shallower than that of the Galactic field stellar
mass function. Combining the mass transformation efficiency ()
from the prestellar core to the star of and the core formation
efficiency (CFE) of 5.5\%, we suggest an overall star formation efficiency of
about 1\% in the CMC. In the single-pointing observations with the IRAM 30m
telescope, we find that 6 cores show blue-skewed profile, while 4 cores show
red-skewed profile. []/[HNC] and []/ in protostellar cores are higher than those in prestellar cores;
this can be used as chemical clocks. The best-fit chemical age of the cores
with line observations is ~years.Comment: Accepted by Astronomy & Astrophysics (A&A
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