899 research outputs found
Finite temperature strong-coupling expansions for the Kondo lattice model
Strong-coupling expansions, to order , are derived for the Kondo
lattice model of strongly correlated electrons, in 1-, 2- and 3- dimensions at
arbitrary temperature. Results are presented for the specific heat, and spin
and charge susceptibilities.Comment: revtex
Two-Hole and Four-Hole Bound States in a t-J Ladder at half-filling
The two-hole excitation spectrum of the t-J ladder at half-filling is studied
using linked-cluster series expansion methods. A rich spectrum of bound states
emerges, particularly at small . Their dispersion relations and coherence
lengths are computed, along with the threshold behaviour as the bound states
merge into the continuum. A class of 4-hole bound states is also studied,
leading to the conclusion that phase separation occurs for ,
in agreement with other studies.Comment: revtex
Surgical excision promotes tumor growth and metastasis by promoting expression of MMP-9 and VEGF in a breast cancer model
Surgery is still the main curative therapeutic modality for breast cancer. Although surgery often results in the successful removal of the primary tumor, its process could increase the risk of metastases of residual cancer cells. Understanding of the connection between breast cancer metastasis and surgical wound will lead to the establishment of a proper treatment strategy for postoperative cancer patient. Aim: To study the influence of surgical procedure on the metastasis of primary breast cancer. Methods: We established MDA-MB-435 human breast cancer xenograft model. Levels of Pro-matrix metalloproteinase 9 (Pro-MMP-9) and vascular endothelial growth factor (VEGF) in host serum and tumors were tested at different time points with ELISA and zymography and correlated to tumor growth and postoperative metastasis. Results: Our study demonstrated surgical wound had promoting effect on tumor growth and pulmonary metastasis of human breast cells, if tumor cells remain in bodies. This effect might be related to the postoperative interaction of cancer and host cells, which resulted in expression of Pro-MMP-9. Surgical process could also increase the VEGF expression in tumor tissues. Conclusions: Surgical wound-produced host Pro-MMP-9 and tumor cell VEGF might be important mediators leading to metastasis of residual breast cancer after surgery.Π₯ΠΈΡΡΡΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ΅ Π»Π΅ΡΠ΅Π½ΠΈΠ΅ Π΄ΠΎ ΡΠΈΡ
ΠΏΠΎΡ ΠΎΡΡΠ°Π΅ΡΡΡ Π³Π»Π°Π²Π½ΡΠΌ ΡΠ΅ΡΠ°ΠΏΠ΅Π²ΡΠΈΡΠ΅ΡΠΊΠΈΠΌ ΠΏΠΎΠ΄Ρ
ΠΎΠ΄ΠΎΠΌ ΠΏΡΠΈ Π»Π΅ΡΠ΅Π½ΠΈΠΈ Π±ΠΎΠ»ΡΠ½ΡΡ
ΡΠ°ΠΊΠΎΠΌ ΠΌΠΎΠ»ΠΎΡΠ½ΠΎΠΉ
ΠΆΠ΅Π»Π΅Π·Ρ. Π₯ΠΎΡΡ Ρ
ΠΈΡΡΡΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠ΄Π°Π»Π΅Π½ΠΈΠ΅ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ Π² Π±ΠΎΠ»ΡΡΠΈΠ½ΡΡΠ²Π΅ ΡΠ»ΡΡΠ°Π΅Π² Π΄ΠΎΡΡΠ°ΡΠΎΡΠ½ΠΎ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎ, Π² ΡΠΎ ΠΆΠ΅ Π²ΡΠ΅ΠΌΡ ΠΎΠ½ΠΎ ΠΌΠΎΠΆΠ΅Ρ
ΡΠ²Π΅Π»ΠΈΡΠΈΡΡ ΡΠΈΡΠΊ ΠΌΠ΅ΡΠ°ΡΡΠ°Π·ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΎΡΡΠ°ΡΠΎΡΠ½ΡΡ
ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ. ΠΠΎΠ½ΠΈΠΌΠ°Π½ΠΈΠ΅ ΡΠ²ΡΠ·ΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΠΌΠ΅ΡΠ°ΡΡΠ°Π·ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΠΏΡΠΈ ΡΠ°ΠΊΠ΅
ΠΌΠΎΠ»ΠΎΡΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ ΠΈ ΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΡΠ°Π½ΠΎΠΉ ΠΏΠΎΠ·Π²ΠΎΠ»ΠΈΡ Π²ΡΠ±ΡΠ°ΡΡ Π½Π°ΠΈΠ»ΡΡΡΡΡ ΡΡΡΠ°ΡΠ΅Π³ΠΈΡ ΠΏΠΎΡΡΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ Π»Π΅ΡΠ΅Π½ΠΈΡ. Π¦Π΅Π»Ρ:
ΠΎΠΏΡΠ΅Π΄Π΅Π»ΠΈΡΡ Π²Π»ΠΈΡΠ½ΠΈΠ΅ Ρ
ΠΈΡΡΡΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π²ΠΌΠ΅ΡΠ°ΡΠ΅Π»ΡΡΡΠ²Π° Π½Π° ΠΌΠ΅ΡΠ°ΡΡΠ°Π·ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ. ΠΠ΅ΡΠΎΠ΄Ρ: Π±ΡΠ»Π° ΡΠΎΠ·Π΄Π°Π½Π° ΠΌΠΎΠ΄Π΅Π»Ρ ΡΠ°ΠΊΠ°
ΠΌΠΎΠ»ΠΎΡΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° Π² Π²ΠΈΠ΄Π΅ ΠΊΡΠ΅Π½ΠΎΡΡΠ°Π½ΡΠΏΠ»Π°Π½ΡΠ°ΡΠ° MDA-MB-435. Π£ΡΠΎΠ²Π΅Π½Ρ Pro-ΠΌΠ°ΡΡΠΈΡΠ½ΠΎΠΉ ΠΌΠ΅ΡΠ°Π»Π»ΠΎΠΏΡΠΎΡΠ΅ΠΈΠ½Π°Π·Ρ 9
(Pro-MMP-9) ΠΈ ΡΠ°ΠΊΡΠΎΡΠ° ΡΠΎΡΡΠ° ΡΠ½Π΄ΠΎΡΠ΅Π»ΠΈΡ ΡΠΎΡΡΠ΄ΠΎΠ² (VEGF) Π² ΡΡΠ²ΠΎΡΠΎΡΠΊΠ΅ ΡΠ΅ΡΠΈΠΏΠΈΠ΅Π½ΡΠ° ΠΈ ΠΎΠΏΡΡ
ΠΎΠ»ΡΡ
ΠΎΡΠ΅Π½ΠΈΠ²Π°Π»ΠΈΡΡ Π² ΡΠ°Π·Π½ΡΠ΅
Π²ΡΠ΅ΠΌΠ΅Π½Π½ΡΠ΅ ΠΏΡΠΎΠΌΠ΅ΠΆΡΡΠΊΠΈ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ELISA ΠΈ Π·ΠΈΠΌΠΎΠ³ΡΠ°ΡΠΈΠΈ. ΠΡΠΈ ΡΡΠΎΠΌ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ»ΠΈ Π½Π°Π»ΠΈΡΠΈΠ΅ ΠΊΠΎΡΠ΅Π»Π»ΡΡΠΈΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΡΡΠΈΠΌΠΈ ΠΏΠΎΠΊΠ°Π·Π°- ΠΈ Π·ΠΈΠΌΠΎΠ³ΡΠ°ΡΠΈΠΈ. ΠΡΠΈ ΡΡΠΎΠΌ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ»ΠΈ Π½Π°Π»ΠΈΡΠΈΠ΅ ΠΊΠΎΡΠ΅Π»Π»ΡΡΠΈΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΡΡΠΈΠΌΠΈ ΠΏΠΎΠΊΠ°Π·Π° ΠΈ Π·ΠΈΠΌΠΎΠ³ΡΠ°ΡΠΈΠΈ. ΠΡΠΈ ΡΡΠΎΠΌ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ»ΠΈ Π½Π°Π»ΠΈΡΠΈΠ΅ ΠΊΠΎΡΠ΅Π»Π»ΡΡΠΈΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΡΡΠΈΠΌΠΈ ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π»ΡΠΌΠΈ,
ΡΠΎΡΡΠΎΠΌ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΠΈ ΠΏΠΎΡΡΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΡΠΌΠΈ ΠΌΠ΅ΡΠ°ΡΡΠ°Π·Π°ΠΌΠΈ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ: Π±ΡΠ»ΠΎ ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½Π°Ρ ΡΠ°Π½Π° ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΡΠ΅Ρ
ΡΠΎΡΡΡ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΠΌΠΎΠ»ΠΎΡΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ ΠΈ Π΅Π΅ ΠΌΠ΅ΡΠ°ΡΡΠ°Π·ΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π² Π»Π΅Π³ΠΊΠΈΠ΅ Π² ΡΠ»ΡΡΠ°Π΅, ΠΊΠΎΠ³Π΄Π° ΠΏΡΠΈ ΡΠ΄Π°Π»Π΅Π½ΠΈΠΈ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ Π² ΡΠ°Π½Π΅
ΠΎΡΡΠ°ΡΡΡΡ ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΠ΅ ΠΊΠ»Π΅ΡΠΊΠΈ. ΠΡΠΎ ΠΌΠΎΠΆΠ΅Ρ Π±ΡΡΡ ΡΠ²ΡΠ·Π°Π½ΠΎ Ρ ΠΏΠΎΡΡΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΡΠΌ Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ΠΌ ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΈ ΠΎΠΊΡΡΠΆΠ°ΡΡΠΈΡ
ΠΈΡ
Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ, ΠΊΠΎΡΠΎΡΠΎΠ΅ ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ Pro-MMP-9. Π£Π΄Π°Π»Π΅Π½ΠΈΠ΅ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΠΌΠΎΠΆΠ΅Ρ ΡΠ°ΠΊΠΆΠ΅ ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΠΎΠ²Π°ΡΡ
ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΡ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ VEGF ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΠΌΠΈ ΠΊΠ»Π΅ΡΠΊΠ°ΠΌΠΈ. ΠΡΠ²ΠΎΠ΄Ρ: Pro-MMP-9, ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΡΡΠ΅ΠΌΡΠΉ Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΡΠΌΠΈ ΠΊΠ»Π΅ΡΠΊΠ°ΠΌΠΈ,
ΠΎΠΊΡΡΠΆΠ°ΡΡΠΈΠΌΠΈ ΠΏΠΎΡΡΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΡΡ ΡΠ°Π½Ρ, Π° ΡΠ°ΠΊΠΆΠ΅ VEGF, ΠΏΡΠΎΠ΄ΡΡΠΈΡΡΠ΅ΠΌΡΠΉ ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΠΌΠΈ ΠΊΠ»Π΅ΡΠΊΠ°ΠΌΠΈ, ΠΌΠΎΠ³ΡΡ Π±ΡΡΡ Π²Π°ΠΆΠ½ΡΠΌΠΈ
ΠΌΠ΅Π΄ΠΈΠ°ΡΠΎΡΠ°ΠΌΠΈ ΠΌΠ΅ΡΠ°ΡΡΠ°Π·ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΎΡΡΠ°ΡΠΎΡΠ½ΡΡ
ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ ΠΏΠΎΡΠ»Π΅ Ρ
ΠΈΡΡΡΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π²ΠΌΠ΅ΡΠ°ΡΠ΅Π»ΡΡΡΠ²Π°
Critical Dynamics of Singlet Excitations in a Frustrated Spin System
We construct and analyze a two-dimensional frustrated quantum spin model with
plaquette order, in which the low-energy dynamics is controlled by spin
singlets. At a critical value of frustration the singlet spectrum becomes
gapless, indicating a quantum transition to a phase with dimer order. This T=0
transition belongs to the 3D Ising universality class, while at finite
temperature a 2D Ising critical line separates the plaquette and dimerized
phases.
The magnetic susceptibility has an activated form throughout the phase
diagram, whereas the specific heat exhibits a rich structure and a power law
dependence on temperature at the quantum critical point.
We argue that the novel quantum critical behavior associated with singlet
criticality discussed in this work can be relevant to a wide class of quantum
spin systems, such as antiferromagnets on Kagome and pyrochlore lattices, where
the low-energy excitations are known to be spin singlets, as well as to the
CAVO lattice and several recently discovered strongly frustrated square-lattice
antiferromagnets.Comment: 5 pages, 5 figures, additional discussion and figure added, to appear
in Phys. Rev.
Series study of the One-dimensional S-T Spin-Orbital Model
We use perturbative series expansions about a staggered dimerized ground
state to compute the ground state energy, triplet excitation spectra and
spectral weight for a one-dimensional model in which each site has an S=\case
1/2 spin and a pseudospin , representing a doubly
degenerate orbital. An explicit dimerization is introduced to allow study of
the confinement of spinon excitations. The elementary triplet represents a
bound state of two spinons, and is stable over much of the Brillouine zone. A
special line is found in the gapped spin-liquid phase, on which the triplet
excitation is dispersionless. The formation of triplet bound states is also
investigated.Comment: 9 pages, 9 figure
Various series expansions for the bilayer S=1/2 Heisenberg antiferromagnet
Various series expansions have been developed for the two-layer, S=1/2,
square lattice Heisenberg antiferromagnet. High temperature expansions are used
to calculate the temperature dependence of the susceptibility and specific
heat. At T=0, Ising expansions are used to study the properties of the
N\'{e}el-ordered phase, while dimer expansions are used to calculate the
ground-state properties and excitation spectra of the magnetically disordered
phase. The antiferromagnetic order-disorder transition point is determined to
be . Quantities computed include the staggered
magnetization, the susceptibility, the triplet spin-wave excitation spectra,
the spin-wave velocity, and the spin-wave stiffness. We also estimates that the
ratio of the intra- and inter-layer exchange constants to be for cuprate superconductor .Comment: RevTeX, 9 figure
A REAL TIME MONITORING MODEL OF THE CALCIUM CARBONATE FOULING INDUCTION PERIOD BASED ON THE CONDUCTANCE TITRATION
A new method has been developed to monitor the calcium carbonate fouling induction period (CCFIP) in real time. Based on the conductance titration, this paper investigated the forming process of CCFIP by a staticdynamic combined simulation experiment unit. With the help of titration analysis (that is titrimetry), an accurate definition of CCFIP and the corresponding real time monitoring model were built up. The investigation results show that the proposed model applies not only to measure the CCFIP in real time, but also applies to an investigation of the influence of various factors on the CCFIP
Minimal immersions of closed surfaces in hyperbolic three-manifolds
We study minimal immersions of closed surfaces (of genus ) in
hyperbolic 3-manifolds, with prescribed data , where
is a conformal structure on a topological surface , and is a holomorphic quadratic differential on the surface . We
show that, for each for some , depending only on
, there are at least two minimal immersions of closed surface
of prescribed second fundamental form in the conformal structure
. Moreover, for sufficiently large, there exists no such minimal
immersion. Asymptotically, as , the principal curvatures of one
minimal immersion tend to zero, while the intrinsic curvatures of the other
blow up in magnitude.Comment: 16 page
Excitation spectrum and ground state properties of the S=1/2 Heisenberg ladder with staggered dimerization
We have studied the excitation spectrum of the quantum spin ladder
with staggered dimerization by dimer series expansions, diagrammatic analysis
of an effective interacting Bose gas of local triplets, and exact
diagonalization of small clusters. We find that the model has two massive
phases, with predominant inter-chain (rung) or intra-chain correlations. The
transition from the rung dimer into the intra-chain dimer phase is
characterized by softening of the triplet spectrum at . The excitation
spectrum as well as the spin correlations away from and close to the critical
line are calculated. The location of the phase boundary is also determined.Comment: 13 pages, 7 figure
Hole dynamics and photoemission in a t-J model for SrCu_2(BO_3)_2
The motion of a single hole in a t-J model for the two-dimensional spin-gap
compound SrCu_2(BO_3)_2 is investigated. The undoped Heisenberg model for this
system has an exact dimer eigenstate and shows a phase transition between a
dimerized and a Neel phase at a certain ratio of the magnetic couplings. We
calculate the photoemission spectrum in the disordered phase using a
generalized spin-polaron picture. By varying the inter-dimer hopping parameters
we find a cross-over between a narrow quasiparticle band regime known from
other strongly correlated systems and free-fermion behavior. The hole motion in
the Neel-ordered phase is also briefly considered.Comment: 4 pages, 3 fig
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