Positive exchange bias in ferromagnetic La0.67Sr0.33MnO3 / SrRuO3 bilayers

Epitaxial La0.67Sr0.33MnO3 (LSMO)/ SrRuO3 (SRO) ferromagnetic bilayers have been grown on (001) SrTiO3 (STO) substrates by pulsed laser deposition with atomic layer control. We observe a shift in the magnetic hysteresis loop of the LSMO layer in the same direction as the applied biasing field (positive exchange bias). The effect is not present above the Curie temperature of the SRO layer (), and its magnitude increases rapidly as the temperature is lowered below . The direction of the shift is consistent with an antiferromagnetic exchange coupling between the ferromagnetic LSMO layer and the ferromagnetic SRO layer. We propose that atomic layer charge transfer modifies the electronic state at the interface, resulting in the observed antiferromagnetic interfacial exchange coupling.Comment: accepted to Applied Physics Letter

In vitro expanded human CD4+CD25+ regulatory T cells suppress effector T cell proliferation.

Regulatory T cells (Tregs) have been shown to be critical in the balance between autoimmunity and tolerance and have been implicated in several human autoimmune diseases. However, the small number of Tregs in peripheral blood limits their therapeutic potential. Therefore, we developed a protocol that would allow for the expansion of Tregs while retaining their suppressive activity. We isolated CD4+CD25 hi cells from human peripheral blood and expanded them in vitro in the presence of anti-CD3 and anti-CD28 magnetic Xcyte Dynabeads and high concentrations of exogenous Interleukin (IL)-2. Tregs were effectively expanded up to 200-fold while maintaining surface expression of CD25 and other markers of Tregs: CD62L, HLA-DR, CCR6, and FOXP3. The expanded Tregs suppressed proliferation and cytokine secretion of responder PBMCs in co-cultures stimulated with anti-CD3 or alloantigen. Treg expansion is a critical first step before consideration of Tregs as a therapeutic intervention in patients with autoimmune or graft-versus-host disease

A general condition of inflationary cosmology on trans-Planckian physics

We consider a more general initial condition satisfying the minimal uncertainty relationship. We calculate the power spectrum of a simple model in inflationary cosmology. The results depend on perturbations generated below a fundamental scale, e.g. the Planck scale.Comment: 7 pages, References adde

Solutions to the Jaynes-Cummings model without the rotating-wave approximation

By using extended bosonic coherent states, the solution to the Jaynes-Cummings model without the rotating-wave approximation can be mapped to that of a polynomial equation with a single variable. The solutions to this polynomial equation can give all eigenvalues and eigenfunctions of this model with all values of the coupling strength and the detuning exactly, which can be readily applied to recent circuit quantum electrodynamic systems operating in the ultra-strong coupling regime.Comment: 6 pages,3 figure

Organoaluminium complexes of ortho-, meta-, para-anisidines: synthesis, structural studies and ROP of ε-caprolactone (and rac-lactide)

Reaction of Me₃Al (two equivalents) with ortho-, meta- or para-anisidine, (OMe)(NH₂)C₆H₄, affords the complexes {[1,2-(OMe),NC₆H₄(μ-Me₂Al)](μ-Me₂Al)}₂ (1), [1,3-(Me₃AlOMe),NHC₆H₄(μ-Me₂Al)]2 (2) or [1,4-(Me₃AlOMe),NHC₆H₄(μ-Me₂Al)]₂ (3), respectively. The molecular structures of 1–3 have been determined and all three complexes were found to be highly active for the ring opening polymerization (ROP) of ε-caprolactone. 1 was found highly active either with or without benzyl alcohol present; at various temperatures, the activity order 1 > 2 ≈ 3 was observed. For the ROP of rac-lactide results for 1–3 were poor

Evolution of Magnetic Interactions in Sb-substituted MnBi2Te4

The Mn(Bi$_{1-x}$Sb$_x$)$_2$Te$_4$ series is purported to span from antiferromagnetic (AF) topological insulator at x = 0 to a trivial AF insulator at x = 1. Here we report on neutron diffraction and inelastic neutron scattering studies of the magnetic interactions across this series. All compounds measured possess ferromagnetic (FM) triangular layers and we find a crossover from AF to FM interlayer coupling near x = 1 for our samples. The large spin gap at x = 0 closes rapidly and the average FM exchange interactions within the triangular layer increase with Sb substitution. Similar to a previous study of MnBi$_2$Te$_4$, we find severe spectral broadening which increases dramatically across the compositional series. In addition to broadening, we observe an additional sharp magnetic excitation in MnSb$_2$Te$_4$ that may indicate the development of local magnetic modes based on recent reports of antisite disorder between Mn and Sb sublattices. The results suggest that both substitutional and antisite disorder contribute substantially to the magnetism in Mn(Bi$_{1-x}$Sb$_x$)$_2$Te$_4$.Comment: 10 pages, 6 figure

Response Surface Optimized Extraction of Total Triterpene Acids from Eriobotrya japonica (Thunb) Lindl (Loquat) Leaf and Evaluation of their In vitro Antioxidant Activities

Purpose: To optimize extraction of total triterpene acids from loquat leaf and evaluate their in vitro antioxidant activities.Methods: The independent variables were ethanol concentration, extraction time, and solvent ratio, while the dependent variable was content of total triterpene acids. Composite design and response surface method were used to optimize the extraction process, while antioxidant activity was evaluated in vitro using α,α-diphenyl-β-picrylhydrazyl (DPPH) and pyrogallol autoxidation methods.Results: The optimum extraction conditions were as follows: 81 % ethanol, extraction time 160 min, and extraction cycles 2, ratio of solvent to sample 14mL/g. Under these conditions, the yield of total triterpene acids reached 3.41 %. Furthermore, total triterpene acids exhibited strong reducing power, as well as radical scavenging activity against DPPH (IC50, 203.41 mg/L) and superoxide anion free radical; when the concentration was > 274.64 mg/L, scavenging ability increased significantly.Conclusion: Total triterpene acids from loquat leaf possess an antioxidant activity in vitro, but further studies are required to develop them into effective drugs and health foods for human applications.Keywords: Eriobotrya japonica (Thunb.) Lindl.,, Triterpene acids, Extraction optimization, Response surface methodology, Antioxidan

System Framework for Digital Monitoring of the Construction of Asphalt Concrete Pavement Based on IoT, BeiDou Navigation System, and 5G Technology

In the construction of asphalt pavement, poor quality is often the main reason for damage to the pavement, which necessitates the use of monitoring systems during the construction stage. Therefore, this study focuses on building an asphalt concrete pavement construction monitoring system to monitor the construction phase. Through a literature review and semi-structured interviews with industry experts, this paper provides an in-depth understanding of the goals and obstacles of asphalt pavement monitoring and discusses directions for improvement. Subsequently, based on the analysis of the interview results, a system framework for asphalt concrete pavement construction monitoring was constructed, and the system was successfully developed and applied to a highway construction project. The results show that the monitoring system significantly improves the construction quality of asphalt concrete pavement, improves the intelligent level of pavement construction management, and promotes the digital development of highway construction