Site-selective doublon-holon dynamics in a pumped one-dimensional Hubbard superlattice with staggered Coulomb interactions

Doublon-holon dynamics is investigated in a pumped one-dimensional Hubbard model with a staggered on?site Coulomb interaction at half-filling. When the system parameters are set to be in the Mott insulating regime the equilibrium sublattice density of states exhibits several characteristic peaks, corresponding to the lower and upper Hubbard bands as well as hybridization bands. We study the linear absorption spectrum and find two main peaks characterizing the photon frequencies which excite the ground state to an excited state. For a system driven by a laser pulse with general intensity and frequency, both the energy absorption and the doublon-holon dynamics exhibit distinct behaviors as a function of laser amplitude and frequency. Single-photon processes are observed at low laser intensity where the energy is absorbed for resonance laser frequencies. For strong laser intensity multi-photon induced dynamics are observed in the system, which are confirmed by an evaluation of the Loschmidt amplitude. The contribution of multi-photon processes to site-specific double occupancy is also characterized by the generalized Loschmidt amplitude. The site-selective doublon-holon dynamics are observed in both the one and multi-photon processes and the site-selective behavior is explained within a quasiparticle picture. Our study suggests strategies to optically engineer the doublon-holon dynamics in one dimensional strongly correlated many-body systems.Comment: 10 pages, 7 figure

Analysis of Gut Flora in a Mouse Model of Esophageal Squamous Cell Carcinoma in Situ

BackgroundWith the application and development of high-throughput sequencing-based approaches for gut flora analysis, increasing studies have confirmed that gut flora is closely related to the development of various cancers. The relationship of gut floras with esophageal squamous cell carcinoma (ESCC) , a common cancer threatening the health of Chinese people, has attracted extensive attention.ObjectiveTo analyze the diversity of gut floras between a rat model of ESCC in situ and normal mice, to identify the carcinoma-specific bacterial genus in ESCC.MethodsFrom August 2020 to May 2021, 20 female SPF C57BL/6 mice were randomly and equally divided into control group and model group. Rice in control group were routinely fed and given ordinary drinking water for 32 weeks, and those in model group were routinely fed and received water containing 0.1 mg/ml cancer inducer 4-nitroquinoline-1-oxide for 16 weeks, and then only fed with ordinary drinking water for another 16 weeks. Stool samples of both groups were collected, and DNA in faeces was extracted and amplified by PCR, followed by high-throughput sequencing. The obtained sequencing data were divided into operational taxonomic units (OTU) based on the similarity between sequences. The α-diversity, β-diversity and species abundance were further analyzed according to species annotation.ResultsNo death occurred in the experiment, and the modeling of ESCC was successfully established in model group. Compared with control group, the proportion of Bacteroidota and Firmicutes increased, while the proportion of Verrucomicrobiota and Proteobacteria decreased in model group. Analysis showed that the α-diversity measured by Shannon Diversity Index in model group was lower than that of control group (P<0.05) . As for β-diversity analysis, PCoA diagram showed that the gut floras of control and model groups clustered in different quadrants, suggesting a significant discrepancy between the groups (t=22.444, P=0.004) . At the phylum level, the abundances of unidentified bacteria, Cyanobacteria, Elusimicrobia and Campilobacterota were higher in model group than those in control group (P<0.05) . At the genus level, the abundances of Prevotellaceae_UCG-003, Bacteroides and Lachnospiraceae_NK4A136_group, Ruminococcus, Prevotellaceae_UCG-001, Prevotella, Colidextribacter, Lachnospiraceae_UCG-006 were higher while those of Romboutsia and Turicibacter were lower in model group than those in control group (P<0.05) . LEfSe analysis showed that, at the genus level, the abundances of Prevotellaceae_UCG-003, Escherichia-Shigella, Bacteroides, Lachnospiraceae_NK4A136_group were increased significantly in model group (P<0.05) , but the abundance of Romboutsia was increased significantly in control group DZ (P<0.05) .ConclusionBy comparing the composition of gut flora, we identified the rat model of ESCC may have less diversity of species and specially differentiated bacteria, and Prevotellaceae_UCG-003, Bacteroides, Lachnospiraceae_NK4A136_group, and Romboutsia could be used as biomarkers for ESCC

Na/K-ATPase mimetic pNaKtide Peptide inhibits the growth of human cancer cells

Cells contain a large pool of non-pumping Na/K-ATPase that participates in signal transduction. Here, we show that the expression of α1 Na/K-ATPase is significantly reduced in human prostate carcinoma as well as in several human cancer cell lines. This down-regulation impairs the ability of Na/K-ATPase to regulate Src-related signaling processes. Supplement of pNaKtide, a peptide derived from α1 Na/K-ATPase, reduces activities of Src and Src effectors. Consequently, these treatments stimulate apoptosis and inhibit growth in cultures of human cancer cells. Moreover, administration of pNaKtide inhibits angiogenesis and growth of tumor xenograft. Thus, the new findings demonstrate the in vivo effectiveness of pNaKtide, and suggest that the defect in Na/K-ATPase-mediated signal transduction may be targeted for developing new anti-cancer therapeutics

Anomalous c-axis charge dynamics in copper oxide materials

Within the t-J model, the c-axis charge dynamics of the copper oxide materials in the underdoped and optimally doped regimes is studied by considering the incoherent interlayer hopping. It is shown that the c-axis charge dynamics is mainly governed by the scattering from the in-plane fluctuation. In the optimally doped regime, the c-axis resistivity is a linear in temperatures, and shows the metallic-like behavior for all temperatures, while the c-axis resistivity in the underdoped regime is characterized by a crossover from the high temperature metallic-like behavior to the low temperature semiconducting-like behavior, which are consistent with experiments and numerical simulations.Comment: 6 pages, Latex, Three figures are adde

Magneto‐responsive polydimethylsiloxane films with magnetic powder: Characterization and potential application in the tensile loading system

Abstract Magnetic actuation has attracted a growing attention due to its non‐contact performance, rapid response and penetrability. The realization of magnetic actuation requires the participation of magneto‐responsive materials (MRMS), and magneto‐responsive polymers (MRPs) are one of the most widely used MRMs. Here, we report the fabrication, characterization and actuation tests of neodymium‐iron‐boron‐polydimethylsiloxane (NdFeB‐PDMS) magnetic films. The NdFeB‐PDMS magnetic film has great flexibility and elasticity, as well as excellent magnetism. The film also shows exceptional deformation and magnetic controllability under magnetic actuation. Besides, it can be driven under a very low magnetic field down to 1mT, and generate an out‐of‐plane displacement of 2.7 mm under the action of magnetic fields. We focus on the tensile deformation of NdFeB‐PDMS films under magnetic driving and provide a possible design for their potential application in the tensile loading system. Preliminary tests demonstrate that the size of tensile deformation is adjusted by controlling the output signal and amplification factor. Highlights Fabrication of NdFeB‐PDMS magnetic films. Mechanical and magnetic characterizations of NdFeB‐PDMS films. Magnetic actuation tests of NdFeB‐PDMS films. Magnetic field‐induced tensile deformation of NdFeB‐PDMS films. Potential application of NdFeB‐PDMS films in the tensile loading system

Vehicle speed guidance strategy at signalized intersection based on cooperative vehicle infrastructure system

In order to reduce stopping time of vehicle at a signalized intersection, aiming at the difficulty, even the impossibility to obtain real-time queue length of intersection in third and fourth-tier cities in China sometimes, a speed guidance strategy based on cooperative vehicle infrastructure system is put forward and studied. For validating the strategy, the traffic signal timing data of the intersection at Hengshan Road and North Fengming Lake Road in Wuhu is collected by a vehicular traffic signal reminder system which is designed. The simulation experiments using the acquired data are done by software VISSIM. The simulation results demonstrate that the strategy under high and low traffic flow can effectively decrease the link travel-time, reducing average ratio is 9.2 % and 13.0 %, respectively, and the effect under low traffic flow is better than that under high traffic flow. The strategy improves efficiency of traffic at a signalized intersection and provides an idea for the application of vehicle speed guidance based on cooperative vehicle infrastructure system

A Multi-Function Conversion Technique for Vehicle-to-Grid Applications

This paper presents a new multi-function conversion technique for vehicle-to-grid (V2G) applications. The proposed bi-directional charger can achieve three functions, including EV battery charging, grid-connection and reactive compensation, which are keys for energy management of the grid. With the proposed multi-function technology, the bi-directional charger will benefit both the grid and electricity customers. A hybrid regulation of energy bi-directional transfer for V2G systems is proposed in this paper, which consists of the battery-side controller and the grid-side controller. This proposed multi-function conversion technique improves the whole system performance with proportional-resonant (PR) control and achieves reactive power compensation with instantaneous reactive theory and a deadbeat control scheme. Simulation and experimental results demonstrate the validity of this new multi-function technique in a V2G system