370 research outputs found
Strain distributions in lattice-mismatched semiconductor core-shell nanowires
The authors study the elastic deformation field in lattice-mismatched
core-shell nanowires with single and multiple shells. The authors consider
infinite wires with a hexagonal cross section under the assumption of
translational symmetry. The strain distributions are found by minimizing the
elastic energy per unit cell using the finite element method. The authors find
that the trace of the strain is discontinuous with a simple, almost piecewise
variation between core and shell, whereas the individual components of the
strain can exhibit complex variations.Comment: 4 pages, 3 figure
Expression of Ets-1, Ang-2 and maspin in ovarian cancer and their role in tumor angiogenesis
<p>Abstract</p> <p>Background</p> <p>Various angiogenic regulators are involved in angiogenesis cascade. Transcription factor Ets-1 plays important role in angiogenesis, remodeling of extracellular matrix, and tumor metastasis. Ets-1 target genes involved in various stages of new blood vessel formation include angiopoietin, matrix metalloproteinases (MMPs) and the protease inhibitor maspin.</p> <p>Methods</p> <p>We used immunohistochemistry (IHC) to detect the expression of Ets-1, angiopoietin-2 (Ang-2) and maspin in ovarian tumor and analyzed the relationship between the expression of these proteins and the clinical manifestation of ovarian cancer.</p> <p>Results</p> <p>Ets-1 expression was much stronger in ovarian cancer compared to benign tumors, but had no significant correlation with other pathological parameters of ovarian cancer. However, Ang-2 and maspin expression had no obvious correlation with pathological parameters of ovarian cancer. Ets-1 had a positive correlation with Ang-2 which showed their close relationship in angiogenesis. Although microvessel density (MVD) value had no significant correlation with the expression of Ets-1, Ang-2 or maspin, strong nuclear expression of maspin appeared to be correlated with high grade and MVD.</p> <p>Conclusions</p> <p>The expression of Ets-1, Ang2 and maspin showed close relationship with angiogenesis in ovarian cancer and expression of maspin appeared to be correlated with high grade and MVD. The mechanisms underlying the cross-talk of the three factors need further investigations.</p
Information entropy-based intention prediction of aerial targets under uncertain and incomplete information
© 2020 by authors. To improve the effectiveness of air combat decision-making systems, target intention has been extensively studied. In general, aerial target intention is composed of attack, surveillance, penetration, feint, defense, reconnaissance, cover and electronic interference and it is related to the state of a target in air combat. Predicting the target intention is helpful to know the target actions in advance. Thus, intention prediction has contributed to lay a solid foundation for air combat decision-making. In this work, an intention prediction method is developed, which combines the advantages of the long short-term memory (LSTM) networks and decision tree. The future state information of a target is predicted based on LSTM networks from real-time series data, and the decision tree technology is utilized to extract rules from uncertain and incomplete priori knowledge. Then, the target intention is obtained from the predicted data by applying the built decision tree. With a simulation example, the results show that the proposed method is effective and feasible for state prediction and intention recognition of aerial targets under uncertain and incomplete information. Furthermore, the proposed method can make contributions in providing direction and aids for subsequent attack decision-makin
Dynamic motion of polar skyrmions in oxide heterostructures
Polar skyrmions have been widely investigated in oxide heterostructure
recently, due to their exotic properties and intriguing physical insights.
Meanwhile, so far, the external field-driven motion of the polar skyrmion, akin
to the magnetic counterpart, has yet to be discovered. Here, using phase-field
simulations, we demonstrate the dynamic motion of the polar skyrmions with
integrated external thermal, electrical, and mechanical stimuli. The external
heating reduces the spontaneous polarization hence the skyrmion motion barrier,
while the skyrmions shrink under the electric field, which could weaken the
lattice pinning and interactions between the skyrmions. The mechanical force
transforms the skyrmions into c-domain in the vicinity of the indenter center
under the electric field, providing the space and driving force needed for the
skyrmions to move. This study confirmed that the skyrmions are quasi-particles
that can move collectively, while also providing concrete guidance for the
further design of polar skyrmion-based electronic devices.Comment: 17 pages, 4 figure
Ionic Signal Amplification of DNA in a Nanopore
Ionic signal amplification is a key challenge for single-molecule analyses by solid-state nanopore sensing. Here, a permittivity gradient approach for amplifying ionic blockade characteristics of DNA in a nanofluidic channel is reported. The transmembrane ionic current response is found to change substantially through modifying the liquid permittivity at one side of a pore with an organic solvent. Imposing positive liquid permittivity gradients with respect to the direction of DNA electrophoresis, this study observes the resistive ionic signals to become larger due to the varying contributions of molecular counterions. On the contrary, negative gradients render adverse effects causing conductive ionic current pulses upon polynucleotide translocations. Most importantly, both the positive and negative gradients are demonstrated to be capable of amplifying the ionic signals by an order of magnitude with a 1.3-fold difference in the transmembrane liquid dielectric constants. This phenomenon allows a novel way to enhance the single-molecule sensitivity of nanopore sensing that may be useful in analyzing secondary structures and genome sequence of DNA by ionic current measurements.This is the pre-peer reviewed version of the following article: Tsutsui, M., Yokota, K., He, Y., Kawai, T., Ionic Signal Amplification of DNA in a Nanopore. Small Methods 2022, 6, 2200761, which has been published in final form at https://doi.org/10.1002/smtd.202200761. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving
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