3,253 research outputs found
Macroscopic Quantum Tunneling Effect of Z2 Topological Order
In this paper, macroscopic quantum tunneling (MQT) effect of Z2 topological
order in the Wen-Plaquette model is studied. This kind of MQT is characterized
by quantum tunneling processes of different virtual quasi-particles moving
around a torus. By a high-order degenerate perturbation approach, the effective
pseudo-spin models of the degenerate ground states are obtained. From these
models, we get the energy splitting of the ground states, of which the results
are consistent with those from exact diagonalization methodComment: 25 pages, 14 figures, 4 table
On the Vertex Operators of the Elliptic Quantum Algebra }
A realization of the elliptic quantum algebra for
any given level is constructed in terms of three free boson fields and
their accompanying twisted partners. It can be viewed as the elliptic
deformation of Wakimoto realization. Two screening currents are constructed;
they commute or anti-commute with modulo total
q-differences. The free fields realization for two types vertex operators
nominated as the type and the type vertex operators are presented. The
twisted version of the two types vertex operators are also obtained. They all
play crucial roles in calculating correlation functions.Comment: 23 page
Anyonic statistics with continuous variables
We describe a continuous-variable scheme for simulating the Kitaev lattice
model and for detecting statistics of abelian anyons. The corresponding quantum
optical implementation is solely based upon Gaussian resource states and
Gaussian operations, hence allowing for a highly efficient creation,
manipulation, and detection of anyons. This approach extends our understanding
of the control and application of anyons and it leads to the possibility for
experimental proof-of-principle demonstrations of anyonic statistics using
continuous-variable systems.Comment: 5 pages, 2 figures, appear in Phys. Rev.
Full one-loop electroweak corrections to associated productions at linear colliders
We study the complete one-loop electroweak(EW) corrections to the processes
of single charged Higgs boson production associated with a neutral Higgs
boson and a gauge boson in the framework of the minimal
supersymmetric standard model(MSSM). Numerical results at the
benchmark point as proposed in the SPA project, are presented for
demonstration. We find that for the process the EW
relative correction can be either positive or negative and in the range of
in our chosen parameter space. While for the processes
the corrections generally reduce the Born cross
sections and the EW relative corrections are typically of order .Comment: 22 pages, 20 figures, LaTex, to be appeared in PR
Longitudinal dependence of B and D meson nuclear modifications in heavy-ion collisions at RHIC and the LHC
It is widely acknowledged that heavy flavor probes are sensitive to the
properties of the quark-gluon plasma and are often considered an important tool
for the plasma tomography studies. Forward rapidity observables can provide
further insight on the dynamics of the medium due to the interplay between the
medium size and the differences in the production spectra of heavy quark
probes. In this proceedings we present the nuclear modification factor
's for B and D mesons, as well as heavy flavor leptons, in the
rapidity range obtained from relativistic Langevin equation
with gluon radiation coupled with a (3+1)-dimensional viscous hydrodynamics
medium background. We present comparison with experimental data at mid-rapidity
as well as predictions for different rapidity ranges.Comment: 4 pages, 4 figures, contribution to the proceedings of Quark Matter -
XXVIII international conference on ultrarelativistic heavy-ion collisions
(Wuhan, China, 4-9 November, 2019
MicroRNA-1 acts as a tumor suppressor microRNA by inhibiting angiogenesis-related growth factors in human gastric cancer
Background
We recently reported that miR-1 was one of the most significantly downregulated microRNAs in gastric cancer (GC) patients from The Cancer Genome Atlas microRNA sequencing data. Here we aim to elucidate the role of miR-1 in gastric carcinogenesis.
Methods
We measured miR-1 expression in human GC cell lines and 90 paired primary GC samples, and analyzed the association of its status with clinicopathological features. The effect of miR-1 on GC cells was evaluated by proliferation and migration assay. To identify the target genes of miR-1, bioinformatic analysis and protein array analysis were performed. Moreover, the regulation mechanism of miR-1 with regard to these predicted targets was investigated by quantitative PCR (qPCR), Western blot, ELISA, and endothelial cell tube formation. The putative binding site of miR-1 on target genes was assessed by a reporter assay.
Results
Expression of miR-1 was obviously decreased in GC cell lines and primary tissues. Patients with low miR-1 expression had significantly shorter overall survival compared with those with high miR-1 expression (P = 0.0027). Overexpression of miR-1 in GC cells inhibited proliferation, migration, and tube formation of endothelial cells by suppressing expression of vascular endothelial growth factor A (VEGF-A) and endothelin 1 (EDN1). Conversely, inhibition of miR-1 with use of antago-miR-1 caused an increase in expression of VEGF-A and EDN1 in nonmalignant GC cells or low-malignancy GC cells.
Conclusions
MiR-1 acts as a tumor suppressor by inhibiting angiogenesis-related growth factors in human gastric cancer. Downregulated miR-1 not only promotes cellular proliferation and migration of GC cells, but may activates proangiogenesis signaling and stimulates the proliferation and migration of endothelial cells, indicating the possibility of new strategies for GC therapy
The elliptic quantum algebra and its vertex operators
We construct a realization of the elliptic quantum algebra
for any given level in terms of free boson fields and
their twisted partners. It can be considered as the elliptic deformation of the
Wakimoto realization of the quantum affine algebra . We also
construct a family of screening currents, which commute with the currents of
up to total q-differences. And we give explicit twisted
expressions for the type and the type vertex operators of
by twisting the known results of the type vertex
operators of the quantum affine algebra and the new results
of the type vertex operators of we obtained in this
paper.Comment: 28 page
Suppressing nano-scale stick-slip motion by feedback
When a micro cantilever with a nano-scale tip is manipulated on a substrate
with atomic-scale roughness, the periodic lateral frictional force and
stochastic fluctuations may induce stick-slip motion of the cantilever tip,
which greatly decreases the precision of the nano manipulation. This unwanted
motion cannot be reduced by open-loop control especially when there exist
parameter uncertainties in the system model, and thus needs to introduce
feedback control. However, real-time feedback cannot be realized by the
existing virtual reality virtual feedback techniques based on the position
sensing capacity of the atomic force microscopy (AFM). To solve this problem,
we propose a new method to design real-time feedback control based on the force
sensing approach to compensate for the disturbances and thus reduce the
stick-slip motion of the cantilever tip. Theoretical analysis and numerical
simulations show that the controlled motion of the cantilever tip tracks the
desired trajectory with much higher precision. Further investigation shows that
our proposal is robust under various parameter uncertainties. Our study opens
up new perspectives of real-time nano manipulation.Comment: 8 pages, 10 figure
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