815 research outputs found
Cross-correlations mediated by Majorana bound states
We consider the correlated parallel transport through two quantum dots which
are tunnel-coupled to the ends of a semiconductor nanowire where the Majorana
bound states (MBSs) may emerge under proper conditions. In terms of the
cross-correlation of currents, we reveal unusual behaviors originated from the
nonlocal MBSs, including such as the distinct symmetry and antisymmetry of the
spectral density in response to the dot-level modulations, and the vanished
cross correlation occurred when any of the dot-levels is in resonance with the
Majorana zero mode
Demonstrating nonlocality induced teleportation through Majorana bound states in a semiconductor nanowire
It was predicted by Tewari [Phys. Rev. Lett. {\bf 100}, 027001 (2008)] that a
teleportationlike electron transfer phenomenon is one of the novel consequences
of the existence of Majorana fermion, because of the inherently nonlocal
nature. In this work we consider a concrete realization and measurement scheme
for this interesting behavior, based on a setup consisting of a pair of quantum
dots which are tunnel-coupled to a semiconductor nanowire and are jointly
measured by two point-contact detectors. We analyze the teleportation dynamics
in the presence of measurement backaction and discuss how the teleportation
events can be identified from the current trajectories of strong response
detectors.Comment: 5 pages, 3 figure
Improving mobility of silicon metal-oxide-semiconductor devices for quantum dots by high vacuum activation annealing
To improve mobility of fabricated silicon metal-oxide-semiconductor (MOS)
quantum devices, forming gas annealing is a common method used to mitigate the
effects of disorder at the Si/SiO2 interface. However, the importance of
activation annealing is usually ignored. Here, we show that a high vacuum
environment for implantation activation is beneficial for improving mobility
compared to nitrogen atmosphere. Low-temperature transport measurements of Hall
bars show that peak mobility can be improved by a factor of two, reaching 1.5
m^2/(Vs) using high vacuum annealing during implantation activation. Moreover,
the charge stability diagram of a single quantum dot is mapped, with no visible
disturbance caused by disorder, suggesting possibility of fabricating
high-quality quantum dots on commercial wafers. Our results may provide
valuable insights into device optimization in silicon-based quantum computing.Comment: 13 pages, 4 figure
Profile of Antibacterial Activities of Essential Oil and Oleoresin from Clove Buds against Several Food-Related Bacteria
The oil from clove buds had a wide range of pharmacological action and bioactivities and is widely used in the medicine, food and flavouring industries. In this work, the antibacterial activity of the essential oil (EO) and oleoresin (OL) from clove buds against several food-related bacteria were evaluated based on Oxford cup method, the minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays, and the results showed that there is no obvious difference in antibacterial activity between essential oil and oleoresin, and they exhibited better antibacterial activity against test bacteria, and the antibacterial effects depended on its concentrations and action time. Kill-time assay also showed the essential oil and oleoresin from clove buds had a significant inhibitory effect on the growth rate of surviving Staphylococcus aureus and Escherichia coli
Expressions of COX-2 and VEGF-C in gastric cancer: correlations with lymphangiogenesis and prognostic implications
<p>Abstract</p> <p>Background</p> <p>Cyclooxygenase-2 (COX-2) has recently been considered to promote lymphangiogenesis by up-regulating vascular endothelial growth factor-C (VEGF-C) in breast and lung cancer. However, the impact of COX-2 on lymphangiogenesis of gastric cancer remains unclear. This study aims to test the expression of COX-2 and VEGF-C in human gastric cancer, and to analyze the correlation with lymphatic vessel density (LVD), clinicopathologic features and survival prognosis.</p> <p>Methods</p> <p>Using immunohistochemistry, COX-2, VEGF-C and level of LVD were analyzed in 56 R0-resected primary gastric adenocarcinomas, while paracancerous normal mucosal tissues were also collected as control from 25 concurrent patients. The relationships among COX-2 and VEGF-C expression, LVD, and clinicopathologic parameters were analyzed. The correlations of COX-2, VEGF-C and level of LVD with patient prognosis were also evaluated by univariate tests and multivariate Cox regression.</p> <p>Results</p> <p>The expression rates of COX-2 and VEGF-C were 69.64% and 55.36%, respectively, in gastric carcinoma. Peritumoral LVD was significantly higher than that in both normal and intratumoral tissue (<it>P </it>< 0.05). It was significantly correlated with lymph node metastasis and invasion depth (<it>P </it>= 0.003, <it>P </it>= 0.05). VEGF-C was significantly associated with peritumoral LVD (<it>r </it>= 0.308, <it>P </it>= 0.021). However, COX-2 was not correlated with VEGF-C (<it>r </it>= 0.110, <it>P </it>= 0.419) or LVD (<it>r </it>= 0.042, <it>P </it>= 0.758). Univariate analysis showed that survival time was impaired by higher COX-2 expression and higher peritumoral LVD. Multivariate survival analysis showed that age, COX-2 expression and peritumoral LVD were independent prognostic factors.</p> <p>Conclusions</p> <p>Although COX-2 expression was associated with survival time, it was not correlated with VEGF-C and peritumoral LVD. Our data did not show that overexpression of COX-2 promotes tumor lymphangiogenesis through an up-regulation of VEGF-C expression in gastric carcinoma. Age, COX-2 and peritumoral LVD were independent prognostic factors for human gastric carcinoma.</p
Active Site Identification and Modification of Electronic States by Atomic-Scale Doping To Enhance Oxide Catalyst Innovation
This work was supported by National Natural Science Foundation of China (No. 21477046) and Key Technology R&D Program of Shandong Province (No. 2016ZDJS11A03).Peer reviewedPostprin
Effect of p21Waf1 and p27Kip1 on centrosome replication and proliferation of breast cancer cell
Aberrant centrosome numbers are detected in virtually all cancers,increasing the risk for cell division errors and chromosomal instability. Deregulation of the centrosome duplication cycle is considered as the major contributing factor for abnormal amplification of centrosomes. p21Waf1 and p27Kip1, general CDK inhibitors by inhibiting cyclin-dependent kinase 2 (CDK2)/cyclin E and cyclin A complexes, controlled the initiation and progress of centrosome duplication . We transfected p21 Waf1, p27 Kip1 or p21 Waf1- p27 Kip1 genes into MCF-7 cells by lipofection to explore the effect of the genes on centrosome duplication and proliferation of breast cancer cell. The result shows that the cell growth was obviously inhibited after being transfected, resulting in an accumulation of cells in G1 and the proportion of cells which contained abnormal centrosomes was obviously decreased. Comparing with p21 Waf1or p27 Kip1, the effects of p21Waf1- p27 Kip1 genes are more significative. These results suggest that p21Waf1 and p27Kip1 genes could inhibit the growth of human breast cancer cells and reverse abnormal duplication of centrosomes. p21Waf1 and p27Kip1 cooperate to regulate centrosome duplication and cell cycle progress, indicating p21 Waf1- p27 Kip1 combined gene might be potential therapeutic agents of breast cancer which reveals suppressed p21Waf1 and p27Kip1 expression
- …