2,411 research outputs found
Tighter weighted polygamy inequalities of multipartite entanglement in arbitrary-dimensional quantum systems
We investigate polygamy relations of multipartite entanglement in
arbitrary-dimensional quantum systems. By improving an inequality and using the
th () power of entanglement of assistance, we provide a
new class of weighted polygamy inequalities of multipartite entanglement in
arbitrary-dimensional quantum systems. We show that these new polygamy
relations are tighter than the ones given in [Phys. Rev. A 97, 042332 (2018)]
Ordering states with various coherence measures
Quantum coherence is one of the most significant theories in quantum physics.
Ordering states with various coherence measures is an intriguing task in
quantification theory of coherence. In this paper, we study this problem by use
of four important coherence measures -- the norm of coherence, the
relative entropy of coherence, the geometric measure of coherence and the
modified trace distance measure of coherence. We show that each pair of these
measures give a different ordering of qudit states when . However, for
single-qubit states, the norm of coherence and the geometric coherence
provide the same ordering. We also show that the relative entropy of coherence
and the geometric coherence give a different ordering for single-qubit states.
Then we partially answer the open question proposed in [Quantum Inf. Process.
15, 4189 (2016)] whether all the coherence measures give a different ordering
of states.Comment: 12 page
Amending coherence-breaking channels via unitary operations
The coherence-breaking channels play a significant role in quantum
information theory. We study the coherence-breaking channels and give a method
to amend the coherence-breaking channels by applying unitary operations. For
given incoherent channel , we give necessary and sufficient conditions
for the channel to be a coherence-breaking channel and amend it via unitary
operations. For qubit incoherent channels that are not
coherence-breaking ones, we consider the mapping and present
the conditions for coherence-breaking and channel amendment as well.Comment: 8 page
Dynamics of coherence-induced state ordering under Markovian channels
We study the dynamics of coherence-induced state ordering under incoherent
channels, particularly four specific Markovian channels: amplitude damping
channel, phase damping channel, depolarizing channel and bit flit channel for
single-qubit states. We show that the amplitude damping channel, phase damping
channel, and depolarizing channel do not change the coherence-induced state
ordering by norm of coherence, relative entropy of coherence, geometric
measure of coherence, and Tsallis relative -entropies, while the bit
flit channel does change for some special cases.Comment: 7 pages, 21 figure
Dual-Octave Convolution for Accelerated Parallel MR Image Reconstruction
Magnetic resonance (MR) image acquisition is an inherently prolonged process,
whose acceleration by obtaining multiple undersampled images simultaneously
through parallel imaging has always been the subject of research. In this
paper, we propose the Dual-Octave Convolution (Dual-OctConv), which is capable
of learning multi-scale spatial-frequency features from both real and imaginary
components, for fast parallel MR image reconstruction. By reformulating the
complex operations using octave convolutions, our model shows a strong ability
to capture richer representations of MR images, while at the same time greatly
reducing the spatial redundancy. More specifically, the input feature maps and
convolutional kernels are first split into two components (i.e., real and
imaginary), which are then divided into four groups according to their spatial
frequencies. Then, our Dual-OctConv conducts intra-group information updating
and inter-group information exchange to aggregate the contextual information
across different groups. Our framework provides two appealing benefits: (i) it
encourages interactions between real and imaginary components at various
spatial frequencies to achieve richer representational capacity, and (ii) it
enlarges the receptive field by learning multiple spatial-frequency features of
both the real and imaginary components. We evaluate the performance of the
proposed model on the acceleration of multi-coil MR image reconstruction.
Extensive experiments are conducted on an {in vivo} knee dataset under
different undersampling patterns and acceleration factors. The experimental
results demonstrate the superiority of our model in accelerated parallel MR
image reconstruction. Our code is available at:
github.com/chunmeifeng/Dual-OctConv.Comment: Proceedings of the 35th AAAI Conference on Artificial Intelligence
(AAAI) 202
MicroRNA-519a promotes proliferation and inhibits apoptosis of hepatocellular carcinoma cells by targeting FOXF2
AbstractRecent studies report that microRNA-519a (miR-519a) is a novel oncomir, which facilitates the onset and progression of human cancers. However, the clinical significance of miR-519a and its functional role and underlying mechanisms in hepatocellular carcinoma (HCC) are poorly investigated. In the present study, elevated expression of miR-519a was observed in HCC tissues compared with adjacent non-tumor tissues. The increased level of miR-519a expression was significantly correlated with adverse clinical features of HCC including hepatitis B virus (HBV) infection, large tumor size, cirrhosis and advanced tumor-node-metastasis tumor stage. Furthermore, high expression of miR-519a was prominently associated with a poorer 5-year overall survival and recurrence-free survival of HCC patients. Gain- and loss-of function experiments showed that miR-519a overexpression enhanced proliferation and reduced apoptosis of Huh7 cells. By contrast, miR-519a knockdown inhibited SMMC-7721 cell proliferation and induced apoptosis. Importantly, up-regulation of miR-519a reduced the expression of FOXF2 mRNA and protein in Huh7 cells, while down-regulation of miR-519a resulted in increased expression of FOXF2 in SMMC-7721 cells. An inverse correlation between mRNA levels of miR-519a and FOXF2 was observed in HCC tissues. Thus, Forkhead box F2 (FOXF2) was identified as a downstream target of miR-519a in HCC. Mechanistically, the effects of miR-519a knockdown on SMMC-7721 cells were abrogated by FOXF2 repression. In conclusion, miR-519a is a novel prognostic predictor for HCC patients and it may potentiate proliferation and inhibits apoptosis of HCC cells by targeting FOXF2
Quantum Fisher information-based detection of genuine tripartite entanglement
Genuine multipartite entanglement plays important roles in quantum
information processing. The detection of genuine multipartite entanglement has
been long time a challenging problem in the theory of quantum entanglement. We
propose a criterion for detecting genuine tripartite entanglement of arbitrary
dimensional tripartite states based on quantum Fisher information. We show that
this criterion is more effective for some states in detecting genuine
tripartite entanglement by detailed example.Comment: 12 pages, 2 figure
Separation and determination of the bioactivity of oosporein from Chaetomium cupreum
Many plants have devised methods of protecting themselves; one of such methods is the use of endophytic fungi. The antagonistic mechanism by endophytic fungi has rarely been revealed. This study investigated Chaetomium cupreum from Macleaya cordata (Willd.) R.Br Herb, which was identified by analysis of morphological characteristics and 28S rDNA sequence. The crystal isolated from culture broth of C. cupreum was identified by X-ray single crystal diffraction as 3,3',6,6'-tetrahydroxy-4,4'- dimethyl-1,1'-bi(cyclohexa-3,6-diene)-2,2',5,5'-tetraone (abbreviated as oosporein). We demonstrated that oosporein had antifungal activity against Rhizoctonia solani, Botrytis cinerea, Pytium ultimum, and antitumor activities against HL-60 and A549. It is toxic to Artemia salina.Keywords: Chaetomium cupreum, toxicity, antifungal activity, oosporein, antitumorAfrican Journal of Biotechnology Vol. 9(36), pp. 5955-5961, 6 September, 201
- …