1,069 research outputs found

    A Note about the General Meromorphic Solutions of the Fisher Equation

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    We employ the complex method to obtain the general meromorphic solutions of the Fisher equation, which improves the corresponding results obtained by Ablowitz and Zeppetella and other authors (Ablowitz and Zeppetella, 1979; Feng and Li, 2006; Guo and Chen, 1991), and wg,i(z) are new general meromorphic solutions of the Fisher equation for c=±5i/6. Our results show that the complex method provides a powerful mathematical tool for solving great many nonlinear partial differential equations in mathematical physics

    A novel multifunctional biomedical material based on polyacrylonitrile:preparation and characterization

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    Wet spun microfibers have great potential in the design of multifunctional controlled release materials. Curcumin (Cur) and vitamin E acetate (Vit. E Ac) were used as a model drug system to evaluate the potential application of the drug-loaded microfiber system for enhanced delivery. The drugs and polyacrylonitrile (PAN) were blended together and spun to produce the target drug-loaded microfiber using an improved wet-spinning method and then the microfibers were successfully woven into fabrics. Morphological, mechanical properties, thermal behavior, drug release performance characteristics, and cytocompatibility were determined. The drug-loaded microfiber had a lobed “kidney” shape with a height of 50 ~ 100 μm and width of 100 ~ 200 μm. The addition of Cur and Vit. E Ac had a great influence on the surface and cross section structure of the microfiber, leading to a rough surface having microvoids. X-ray diffraction and Fourier transform infrared spectroscopy indicated that the drugs were successfully encapsulated and dispersed evenly in the microfilament fiber. After drug loading, the mechanical performance of the microfilament changed, with the breaking strength improved slightly, but the tensile elongation increased significantly. Thermogravimetric results showed that the drug load had no apparent adverse effect on the thermal properties of the microfibers. However, drug release from the fiber, as determined through in-vitro experiments, is relatively low and this property is maintained over time. Furthermore, in-vitro cytocompatibility testing showed that no cytotoxicty on the L929 cells was found up to 5% and 10% respectively of the theoretical drug loading content (TDLC) of curcumin and vitamin E acetate. This study provides reference data to aid the development of multifunctional textiles and to explore their use in the biomedical material field

    A Bayesian Federated Learning Framework with Online Laplace Approximation

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    Federated learning (FL) allows multiple clients to collaboratively learn a globally shared model through cycles of model aggregation and local model training, without the need to share data. Most existing FL methods train local models separately on different clients, and then simply average their parameters to obtain a centralized model on the server side. However, these approaches generally suffer from large aggregation errors and severe local forgetting, which are particularly bad in heterogeneous data settings. To tackle these issues, in this paper, we propose a novel FL framework that uses online Laplace approximation to approximate posteriors on both the client and server side. On the server side, a multivariate Gaussian product mechanism is employed to construct and maximize a global posterior, largely reducing the aggregation errors induced by large discrepancies between local models. On the client side, a prior loss that uses the global posterior probabilistic parameters delivered from the server is designed to guide the local training. Binding such learning constraints from other clients enables our method to mitigate local forgetting. Finally, we achieve state-of-the-art results on several benchmarks, clearly demonstrating the advantages of the proposed method

    Characterization of a sensitive biosensor based on an unmodified DNA and gold nanoparticle composite and its application in diquat determination

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    AbstractDNA usually adsorbs gold nanoparticles by virtue of mercapto or amino groups at one end of a DNA molecule. However, in this paper, we report a sensitive biosensor constructed using unmodified DNA molecules with consecutive adenines (CA DNA) and gold nanoparticles (GNPs). The CA DNA–GNP composite was fabricated on gold electrodes and characterized by using of scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and the electrochemical method. Using an electrochemical quartz crystal microbalance (EQCM), the mechanism by which the CA DNA and GNPs combined was also studied. The modified electrode exhibited an ultrasensitive response to diquat. Differential pulse voltammetry (DPV) was used to study the linear relationships between concentrations and reduction peak currents, ranging from 1.0×10−9M to 1.2×10−6M. The detection limit of it is 2.0×10−10M. The feasibility of the proposed assay for use in human urine and grain was investigated, and the satisfactory results were obtained

    Efficacy of intravitreal ranibizumab injection combined with macular grid photocoagulation for diabetic macular edema

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    AIM:To evaluate the clinical efficacy of intravitreal injection of ranibizumab combined with macular grid photocoagulation for diabetic macular edema(DME).<p>METHODS:Totally 60 eyes(60 patients)with DME were randomly divided into 2 groups: 30 eyes of simple injection group underwent intravitreal injection of ranibizumab, and 30 eyes of combined treatment group underwent intravitreal injection of ranibizumab and macular grid photocoagulation 1wk later. The best corrected visual acuity(BCVA), central macular thickness(CMT)measured by optical coherence tomography(OCT)and postoperative complications were observed.<p>RESULTS:In simple injection group, the BCVA after operation were separately 0.390±0.075(4wk), 0.367±0.088(8wk)and 0.319±0.064(12wk),the CMT after operation were separately 221.63±112.34μm(4wk), 337.73±99.56μm(8wk)and 432.92±100.46μm(12wk), which were much better than pre-operation. But during follow-up, the BCVA presented down trend and the CMT was on the rise slowly. In combined treatment group, the BCVA after operation were separately 0.385±0.036(4wk), 0.382±0.079(8wk)and 0.377±0.097(12wk),the CMT after operation were separately 249.77±106.55μm(4wk), 270.40±92.88μm(8wk)and 275.84±97.34μm(12wk), which were satisfactory and steady during follow-up, better than simple injection group(<i>P</i><0.05).<p>CONCLUSION:Intravitreal injection of ranibizumab can effectively improve visual acuity and decrease central foveal thickness for patients with DME, combining with macular grid photocoagulation can ensure therapeutic effects steady and permanent

    (2,2′-Bipyridine-κ2 N,N′){N-[2-oxido-5-(phenyl­diazen­yl)benzyl­idene-κO]glycinato-κ2 N,O}copper(II)

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    In the title compound, [Cu(C15H11N3O3)(C10H8N2)], the CuII atom is five-coordinated in a distorted square-pyramidal CuN3O2 geometry. The basal positions are occupied by three donor atoms from the tridentate Schiff base ligand and by one N atom from the 2,2′-bipyridine ligand. The axial position is occupied by the other N atom of the 2,2′-bipyridine ligand. The crystal structure is consolidated by weak C—H⋯O hydrogen bonds. In addition, π–π inter­actions between adjacent pyridine rings (centroid–centroid distances = 3.238 and 3.313 Å) may also stabilize the crystal packing

    Neo-sex chromosomes in the black muntjac recapitulate incipient evolution of mammalian sex chromosomes

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    The nascent neo-sex chromosomes of black muntjacs show that regulatory mutations could accelerate the degeneration of the Y chromosome and contribute to the further evolution of dosage compensation
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