2,692 research outputs found

    Gutzwiller density functional calculations of the electronic structure of FeAs-based superconductors: Evidence for a three-dimensional Fermi surface

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    The electronic structures of FeAs-compounds strongly depend on the Fe-As bonding, which can not be described successfully by the local density approximation (LDA). Treating the multi-orbital fluctuations from abab-initioinitio by LDA+Gutzwiller method, we are now able to predict the correct Fe-As bond-length, and find that Fe-As bonding-strength is 30% weaker, which will explain the observed "soft phonon". The bands are narrowed by a factor of 2, and the d3z2r2d_{3z^2-r^2} orbital is pushed up to cross the Fermi level, forming 3-dimensional Fermi surfaces, which suppress the anisotropy and the (π,π\pi,\pi) nesting. The inter-orbital Hund's coupling JJ rather than UU plays crucial roles to obtain these results.Comment: 4 pages, 4 figures, 1 tabl

    Noncollinearity-modulated electronic properties of the monolayer CrI3_3

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    Introducing noncollinear magnetization into a monolayer CrI3_3 is proposed to be an effective approach to modulate the local electronic properties of the two-dimensional (2D) magnetic material. Using first-principles calculation, we illustrate that both the conduction and valence bands in the monolayer CrI3_3 are lowered down by spin spiral states. The distinct electronic structure of the monolayer noncollinear CrI3_3 can be applied in nanoscale functional devices. As a proof of concept, we show that a magnetic domain wall can form a one-dimensional conducting channel in the 2D semiconductor via proper gating. Other possible applications such as electron-hole separation and identical quantum dots are also discussed

    Collective synchronization induced by epidemic dynamics on complex networks with communities

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    Much recent empirical evidence shows that \textit{community structure} is ubiquitous in the real-world networks. In this Letter, we propose a growth model to create scale-free networks with the tunable strength (noted by QQ) of community structure and investigate the influence of community strength upon the collective synchronization induced by SIRS epidemiological process. Global and local synchronizability of the system is studied by means of an order parameter and the relevant finite-size scaling analysis is provided. The numerical results show that, a phase transition occurs at Qc0.835Q_c\simeq0.835 from global synchronization to desynchronization and the local synchronization is weakened in a range of intermediately large QQ. Moreover, we study the impact of mean degree upon synchronization on scale-free networks.Comment: 5 pages, 4 figures. to appeared in Phys. Rev. E 75 (2007

    Detecting Non-Uniform structures in Oil-in-Water Bubbly Flow Experiments

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    Acknowledgements This work was supported in part by the National Natural Science Foundation of China, under Grant 62373278, 52378254 and 41704131, and in part by the National Natural Science Foundation of Tianjin, China, under Grant 21JCJQJC00130, and in part by the Taishan Industrial Experts Program.Peer reviewe

    Smoking, immunity, and cardiovascular prognosis: a study of plasma IgE concentration in patients with acute myocardial infarction

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    BackgroundImmunoglobulin E (IgE) is implicated in the pathogenesis of acute myocardial infarction (AMI), and smokers often exhibit elevated plasma IgE levels. However, it remains uncertain whether the role of smoking in the development and prognosis of AMI is influenced by IgE levels. This study aimed to investigate the potential contribution of IgE in mediating the association between smoking and AMI.MethodsWe conducted a prospective study involving 348 consecutive patients with chest discomfort who underwent coronary angiography. Plasma cotinine, an alkaloid present in tobacco, and IgE levels were measured. The patients were followed up for mean 39-months to assess their long-term prognosis based on major adverse cardiac and cerebrovascular events (MACCE).ResultsOur findings indicate that patients with AMI had higher plasma levels of cotinine and IgE. Univariate analyses demonstrated a positive association between plasma cotinine (OR = 1.7, 95% CI: 1.27–2.26, P < 0.001) and IgE (OR = 2.8, 95% CI: 1.75–4.39, P < 0.001) with AMI. Receiver operating characteristics analyses showed that the combined use of cotinine and IgE (AUC: 0.677) had a larger predictive performance compared to cotinine alone (AUC: 0.639) or IgE alone (AUC: 0.657), although the improvement did not reach statistical significance. Multivariable logistic regression revealed a positive association between plasma cotinine and AMI (OR = 1.70, 95% CI: 1.04–2.78, P = 0.036). Furthermore, the inclusion of plasma IgE in the regression model led to a decrease in the OR and 95% CI of plasma cotinine (OR = 1.66, 95% CI: 1.01–2.73, P = 0.048). Process mediation analyses showed a significant indirect effect of plasma cotinine on AMI mediated through increased plasma IgE. Kaplan–Meier analysis during a mean 39-months follow-up revealed that higher plasma levels of IgE were associated with an increased risk of MACCE following AMI (P = 0.047). However, in the context of the COX regression analysis, no significant correlation was observed between IgE, cotinine and AMI.ConclusionCotinine exhibits a positive association with AMI, wherein IgE plays a mediating role. Elevated plasma levels of IgE was positively associated with AMI and poor prognosis, which further confirms the adverse role of smoking on the incidence of AMI and prognosis. (Clinical trial registration: ChiCTR2100053000)

    Trans-Anastomotic Drainage Tube Placement After Hand-Sewn Anastomosis in Patients Undergoing Intersphincteric Resection for Low Rectal Cancer: An Alternative Drainage Method

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    Anastomotic leakage (AL) is a common complication after intersphincteric resection (ISR). It significantly reduces quality of life and causes great distress to patients. Although traditional drainage (e.g., anal and pelvic catheters) may reduce the impact of AL to some extent, their role in reducing the incidence of AL remains controversial. In this study, we developed a novel drainage technique involving the placement of drainage tubes through the gap between sutures during handsewn anastomosis, to reduce the occurrence of anastomotic leakage. We retrospectively analyzed 34 consecutive patients who underwent intersphincteric resection requiring handsewn anastomosis between February 1, 2017, and January 1, 2021. Patients were classified into the trans-anastomotic drainage tube group (TADT, n = 14) and the non-TADT group (n = 20) based on whether trans-anastomotic tube placement was performed. The incidence of postoperative complications, such as AL, was compared between the two groups, and anal function of patients at 1-year post-ISR was evaluated. Six cases of AL occurred in the non-TADT group, while none occurred in the TADT group; this difference was statistically significant (p=0.031). The TADT group also had a shorter hospital stay (p=0.007). There were no other significant intergroup differences in operation time, blood loss, pain score, anastomotic stenosis, intestinal obstruction, or incidence of wound infection. In the 30 patients (88.2%) evaluated for anal function, there were no significant intergroup differences in stool frequency, urgency, daytime/nocturnal soiling, Wexner incontinence score, or Kirwan grading. Taken together, trans-anastomotic tube placement is a novel drainage method that may reduce AL after ISR requiring handsewn anastomosis and without adversely affecting anal function

    Brilliant circularly polarized γ\gamma-ray sources via single-shot laser plasma interaction

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    Circularly polarized (CP) γ\gamma-ray sources are versatile for broad applications in nuclear physics, high-energy physics and astrophysics. The laser-plasma based particle accelerators provide accessibility for much higher flux γ\gamma-ray sources than conventional approaches, in which, however, the circular polarization properties of emitted γ\gamma-photons are used to be neglected. In this letter, we show that brilliant CP γ\gamma-ray beams can be generated via the combination of laser plasma wakefield acceleration and plasma mirror techniques. In weakly nonlinear Compton scattering scheme with moderate laser intensities, the helicity of the driving laser can be transferred to the emitted γ\gamma-photons, and their average polarization degree can reach about 37%\sim 37\% (21%21\%) with a peak brilliance of 1021 \gtrsim 10^{21}~photons/(s \cdot mm2^2 \cdot mrad2^2 \cdot 0.1% BW) around 1~MeV (100~MeV). Moreover, our proposed method is easily feasible and robust with respect to the laser and plasma parameters

    Molecular Cloning, Expression Profile and 5′ Regulatory Region Analysis of Two Chemosensory Protein Genes from the Diamondback Moth, Plutella xylostella

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    Chemosensory proteins play an important role in transporting chemical compounds to their receptors on dendrite membranes. In this study, two full-length cDNA codings for chemosensory proteins of Plutella xylostella (Lepidoptera: Plutellidae) were obtained by RACE-PCR. PxylCSP3 and Pxyl-CSP4, with GenBank accession numbers ABM92663 and ABM92664, respectively, were cloned and sequenced. The gene sequences both consisted of three exons and two introns. RT-PCR analysis showed that Pxyl-CSP3 and Pxyl-CSP4 had different expression patterns in the examined developmental stages, but were expressed in all larval stages. Phylogenetic analysis indicated that lepidopteran insects consist of three branches, and Pxyl-CSP3 and Pxyl-CSP4 belong to different branches. The 5′regulatory regions of Pxyl-CSP3 and Pxyl-CSP4 were isolated and analyzed, and the results consist of not only the core promoter sequences (TATA-box), but also several transcriptional elements (BR-C Z4, Hb, Dfd, CF2-II, etc.). This study provides clues to better understanding the various physiological functions of CSPs in P. xylostella and other insects

    Generation of γ\gamma photons with extremely large orbital angular momenta

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    Vortex γ\gamma photons, which carry large intrinsic orbital angular momenta (OAM), have significant applications in nuclear, atomic, hadron, particle and astro-physics, but their production remains unclear. In this work, we investigate the generation of such photons from nonlinear Compton scattering of circularly polarized monochromatic lasers on vortex electrons. We develop a quantum radiation theory for ultrarelativistic vortex electrons in lasers by using the harmonics expansion and spin eigenfunctions, which allows us to explore the kinematical characteristics, angular momentum transfer mechanisms, and formation conditions of vortex γ\gamma photons. The multiphoton absorption of electrons enables the vortex γ\gamma photons, with fixed polarizations and energies, to exist in mixed states comprised of multiple harmonics. Each harmonic represents a vortex eigenmode and has transverse momentum broadening due to transverse momenta of the vortex electrons. The large topological charges associated with vortex electrons offer the possibility for γ\gamma photons to carry adjustable OAM quantum numbers from tens to thousands of units, even at moderate laser intensities. γ\gamma photons with large OAM and transverse coherence length can assist in influencing quantum selection rules and extracting phase of the scattering amplitude in scattering processes.Comment: 7 pages, 4 figure
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