Applications of complex-valued neural networks (CVNNs) have expanded widely in recent years-in particular in radar and coherent imaging systems. In general, the most important merit of neural ...networks lies in their generalization ability. This paper compares the generalization characteristics of complex-valued and real-valued feedforward neural networks in terms of the coherence of the signals to be dealt with. We assume a task of function approximation such as interpolation of temporal signals. Simulation and real-world experiments demonstrate that CVNNs with amplitude-phase-type activation function show smaller generalization error than real-valued networks, such as bivariate and dual-univariate real-valued neural networks. Based on the results, we discuss how the generalization characteristics are influenced by the coherence of the signals depending on the degree of freedom in the learning and on the circularity in neural dynamics.
Polymers have been widely used for biomedical purposes such as medical devices, tissue engineering scaffolds, and drug carriers for drug delivery system (DDS). Using polymers for such medical devices ...should be entirely sensible, as polymers are generally very soft, highly cost-effective, and relatively biocompatible. In order to encourage further development in the biocompatibility of the polymers for the enhanced use of the materials, the functionalization of the polymer surfaces has been deliberately introduced. Plasma modification is one of the most efficient ways for the surface treatment of polymers, since plasma treatment could selectively modify the chemical and the physical properties of the surface of the polymers by not affecting the original bulk characteristics of the polymers. Also, plasma surface modification offers shorter treatment time as compared with other surface modification methods. When plasma was applied to the polymer surface, functional groups, graft polymerization, coatings, and molecular crosslinking formation would be introduced with or without the change in the surface roughness of the polymer. The highly functionalized polymers by the plasma modifications would be effectively used for the materials in tissue engineering or drug delivery systems. In this paper, the fabrication and the characterization of polymers by several types of plasma treatments are reviewed, followed by the introduction of their applications to the materials in drug delivery systems and tissue engineering.
•Studies on plasma treatments of polymers for biomedical applications are reviewed.•Achievements in biocompatibility by plasma treatments are discussed.•Plasma-modified polymeric surfaces were studied for structural characterization.•Biocompatibility and mechanical property of DLC-related coatings were summarized.•Plasma technique is a promising modification tool for DDS and tissue engineering.
We report spectroscopic observation of Rydberg polarons in an atomic Bose gas. Polarons are created by excitation of Rydberg atoms as impurities in a strontium Bose-Einstein condensate. They are ...distinguished from previously studied polarons by macroscopic occupation of bound molecular states that arise from scattering of the weakly bound Rydberg electron from ground-state atoms. The absence of a p-wave resonance in the low-energy electron-atom scattering in Sr introduces a universal behavior in the Rydberg spectral line shape and in scaling of the spectral width (narrowing) with the Rydberg principal quantum number, n. Spectral features are described with a functional determinant approach (FDA) that solves an extended Fröhlich Hamiltonian for a mobile impurity in a Bose gas. Excited states of polyatomic Rydberg molecules (trimers, tetrameters, and pentamers) are experimentally resolved and accurately reproduced with a FDA.
We propose two major revisions on the rate‐ and state‐dependent friction (RSF) law on the basis of rigorous analysis of friction experiments. First, we find that the direct effect coefficient a, a ...parameter playing a central role in the RSF constitutive law, is much larger than the traditional, consensual estimate of less than about 0.01. We derive a lower bound of 0.035 for a directly from stress‐velocity relations measured during carefully designed step tests, without relying on any evolution laws as traditional methods do. After correcting for state changes during the steps, inferred indirectly from observed changes in acoustic transmissivities across the interface, we obtain an estimate of a as large as 0.05. Second, we calculate values of the RSF state variable Φ by feeding the measured shear stress and slip velocity values into the constitutive law. The results showed systematic deviations from predictions of the RSF evolution law of the aging type. This leads us to propose a revised evolution law, which incorporates a previously unknown weakening effect related to the shear stress. We also present additional experiment results to corroborate the presence of this new effect. Forward simulations based on our revised evolution law, combined with the larger, revised value of a, very well explain observed variations in both the shear stress and Φ throughout different phases of experiments, including quasi‐static hold, reloading after a hold, and steady state sliding at different velocities, as well as their mutual transitions, all with an identical set of parameter values.
Key Points
Novel method to estimate the direct effect coefficient of rate/state friction
Revealing a hitherto unknown weakening effect caused by shear stress increase
Revised formula for rate/state friction that can explain observations very well
We present an improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a ...significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>1.07×10^{26} yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.
The microstructure and mechanical properties of a (L12+B2) AlCoCrFeNi2.1 eutectic high entropy alloy (EHEA) processed by severe warm-rolling were investigated in the present work. The EHEA was ...successfully warm-rolled up to 90% reduction in thickness at 400 °C, 600 °C and 750 °C. Considerable differences in the microstructural evolution were identified during warm-rolling at the three temperatures. The L12 phase in the EHEA was disordered due to severe warm-rolling at 400 °C and 750 °C, while a predominantly ordered structure was retained in the EHEA warm-rolled at 600 °C. This anomalous behavior could be adequately explained by the sluggish ordering kinetics at lower deformation temperatures. The EHEA warm-rolled at 750 °C showed an extremely heterogeneous microstructure featured by retained lamellar regions comprising of B2 and FCC lamellae with dispersed B2 phase inside the FCC, whereas the non-lamellar regions showed a mixture of ultrafine to nanocrystalline disordered FCC, ordered B2 and Cr-rich σ phases. The non-lamellar regions were scarce and nearly absent in the EHEA 90% warm-rolled at 600 °C and 400 °C, respectively. The remarkably heterogeneous microstructure of EHEA warm-rolled at 750 °C resulted in outstanding strength-ductility combination with tensile strength ~1635 MPa and elongation to failure ~18%. The results indicated tremendous potential for achieving superior mechanical properties in heterogeneous EHEAs processed by severe warm-rolling.
Aims
To assess the effects of renal impairment (RI) on the efficacy and safety of ipragliflozin in patients with type 2 diabetes mellitus (T2DM).
Methods
A cohort of Japanese patients with T2DM and ...mild to moderate RI and poor glycaemic control, despite diet/exercise therapy alone or diet/exercise therapy in combination with an oral hypoglycaemic agent (an α‐glucosidase inhibitor, a sulfonylurea, or pioglitazone), were randomized in a double‐blind manner to 50 mg ipragliflozin or placebo once daily for 24 weeks. The patients continued open‐label ipragliflozin for a 28‐week extension period (total treatment duration: 52 weeks).
Results
Ipragliflozin significantly decreased glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) levels and body weight from baseline to week 24 (last observation carried forward) compared with placebo in all patients with RI. The decreases in HbA1c and FPG levels were statistically significant in patients with mild RI, but not in patients with moderate RI. Ipragliflozin significantly reduced body weight in both RI groups. The improvements in glycaemic control were maintained in the 28‐week extension period. Ipragliflozin was associated with no clinically significant safety concerns, and its safety profiles were not influenced by the severity of RI.
Conclusions
Ipragliflozin significantly improved glycaemic control and body weight in patients with T2DM with mild RI, but did not improve glycaemic control in patients with moderate RI. Ipragliflozin is a valid treatment option for patients with mild RI but not those with moderate RI.
In cases of pulp exposure due to deep dental caries or severe traumatic injuries, existing pulp-capping materials have a limited ability to reconstruct dentin-pulp complexes and can result in ...pulpectomy because of their low potentials to accelerate dental pulp cell activities, such as migration, proliferation, and differentiation. Therefore, the development of more effective therapeutic agents has been anticipated for direct pulp capping. Dental pulp tissues are enriched with dental pulp stem cells (DPSCs). Here, the authors investigated the effects of semaphorin 3A (Sema3A) on various functions of human DPSCs in vitro and reparative dentin formation in vivo in a rat dental pulp exposure model. Immunofluorescence staining revealed expression of Sema3A and its receptor Nrp1 (neuropilin 1) in rat dental pulp tissue and human DPSC clones. Sema3A induced cell migration, chemotaxis, proliferation, and odontoblastic differentiation of DPSC clones. In addition, Sema3A treatment of DPSC clones increased β-catenin nuclear accumulation, upregulated expression of the FARP2 gene (FERM, RhoGEF, and pleckstrin domain protein 2), and activated Rac1 in DPSC clones. Furthermore, in the rat dental pulp exposure model, Sema3A promoted reparative dentin formation with dentin tubules and a well-aligned odontoblast-like cell layer at the dental pulp exposure site and with novel reparative dentin almost completely covering pulp tissue at 4 wk after direct pulp capping. These findings suggest that Sema3A could play an important role in dentin regeneration via canonical Wnt/β-catenin signaling. Sema3A might be an alternative agent for direct pulp capping, which requires further study.
This multicenter, double‐blind, placebo‐controlled study examined the efficacy and safety of ipragliflozin, a sodium‐glucose co‐transporter 2 inhibitor, in combination with metformin in Japanese ...patients with type 2 diabetes mellitus (T2DM). Patients were randomized in a 2 : 1 ratio to 50 mg ipragliflozin (n = 112) or placebo (n = 56) once daily for 24 weeks, followed by a 28‐week open‐label extension in which all patients received 50 or 100 mg ipragliflozin, while continuing metformin. The primary outcome was the change in glycated haemoglobin (HbA1c) from baseline to week 24. HbA1c decreased significantly in the ipragliflozin group (−0.87%; adjusted mean difference from placebo: −1.30%; p < 0.001). The overall incidence of treatment‐emergent adverse events was similar in both groups, although pollakiuria and constipation were more common in the ipragliflozin group; thus, ipragliflozin significantly improved glycaemic control and reduced body weight without major safety issues in Japanese patients with T2DM.
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