•A modified coaxial electrospinning for creating hypromellose-based composite fibers.•Quantitative analyses of Taylor cone and straight fluid jet during electrospinning.•Amorphous hydrophilic ...nanocomposites consisting of multiple components.•Improved performances about the fast dissolution of poorly water-soluble drug.
Hypromellose (HPMC)-based hydrophilic composites (HCs) used for rapid dissolution of ferulic acid (FA) were investigated. Electrospun and casting HCs were prepared from a solution containing HPMC, FA, and polyethylene glycol. Ethanol was used as sheath fluid during coaxial processes, and the effects of its flow rates on the Taylor cone and straight fluid jet were investigated. The morphology, component state, hydrophilicity, and drug dissolution rate of the HCs were characterized. Results demonstrated that all HCs were amorphous materials, and their components were compatible. However, the dissolution rate of electrospun HCs was 10 times faster than that of casting HCs. The smaller the diameters of electrospun HCs were, the better their performances were. The mechanism of electrospun HCs was suggested. By utilizing modified coaxial electrospinning and combinations of drug carriers, new types of HPMC-based HCs can provide an alternative approach for the effective delivery of poorly water-soluble drugs.
A hybrid approach that combines the strategy of partial density tapering (PDT) and the multiobjective particle swarm optimization (MOPSO), called PDT-MOPSO, is proposed to address the synthesis of ...sparse planar arrays (SPAs) of different shapes. By performing the PDT, not only the strong constraint of element placement in SPAs is eased to nonconstrained issue, but also the element locations are forced to follow the distribution of density tapering somewhat to facilitate the sidelobe suppression. Then, by taking the sidelobe level (SLL) and directivity as the optimization objectives, the traditional MOPSO is used to optimize the element locations so that the SPAs with reduced number of elements, minimized SLL and nondegraded directivity are achieved. Some numerical instances confirmed the effectiveness of the proposed method.
Patent ductus arteriosus (PDA) is one of the most common congenital heart diseases. Once the PDA is diagnosed, it needs to be dealt with in time. At present, main methods include pharmacological ...treatment, surgical closure, and interventional closure for treatment of PDA. However, the effect of different interventions in PDA management is still controversial. Thus, our study aims to assess the effectiveness of different interventions together and estimate the sequence of these therapies for PDA children. Meanwhile, it is necessary to conduct a Bayesian network meta-analysis to compare the safety of different interventions comprehensively.
To the best of our knowledge, this is the first Bayesian network meta-analysis comparing the efficacy and safety of different interventions for the treatment of PDA. PubMed, Embase, Cochrane Library, Web of Science, gray literature, and trial registry databases were searched from inception to December 2022. We will extract and report data according to methodological guidelines for Bayesian network meta-analysis by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P). Primary PDA closure, overall PDA closure, technical success, surgical success rate, mortality during hospital stay, operation time, intensive care unit stay, intraoperative radiation dose, radiation exposure time, total postoperative complication rate, and postoperative major complication rate will be defined as the outcomes. The quality of all random studies will be assessed using ROB, and quality of evidence for all outcomes will be judged by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).
The results will be disseminated through peer-reviewed publication. Since no private and confidential patient data will be contained in the reporting, there are no ethical considerations associated with this protocol.
INPLASY2020110067.
The oral delivery of active ingredients for the fast onset of therapeutic effects is a well-known method in patients. In this study, a new kind of hydrophilic Janus structural nanocomposite was ...designed for the rapid dissolution and transmembrane permeation of helicid, an herbal medicine with poor water solubility. A side-by-side electrospinning process characterized by an eccentric spinneret was developed to fabricate the Janus nanocomposites. The morphology, inner structure, incorporated components and their physical states, hydrophilicity, and functional performances of the Janus nanocomposites were investigated. The experimental results demonstrated that an unspinnable fluid (polyvinylpyrrolidone K10–sodium dodecyl sulfate) could be simultaneously treated with an electrospinnable fluid (polyvinylpyrrolidone K90–helicid) to create Janus structural nanocomposites. The prepared Janus nanofibers exhibited linear morphology and notable side-by-side inner structure with all the incorporated components present in an amorphous state. Both the control of monolithic nanocomposites and the Janus composites can provide more than 10-fold the transmembrane rates of crude helicid particles. Compared with monolithic nanocomposites, the Janus nanocomposites exhibited improved hydrophilicity and can further promote the dissolution and transmembrane permeation of helicid for a potentially faster onset of therapeutic actions. The generation mechanisms and functional performance of Janus nanocomposites were suggested. The preparation protocols reported here can provide a useful approach for designing and developing new functional nanocomposites in the form of Janus structures. Meanwhile, the medicated hydrophilic Janus nanocomposites represent a newly developed kind of nano drug delivery system for the fast onset of therapeutic action of orally administered water-insoluble drugs.
To extend multiobjective evolutionary algorithm based on decomposition (MOEA/D) in higher dimensional objective spaces, this paper proposes a new version of MOEA/D with uniform design, named the ...uniform design multiobjective evolutionary algorithm based on decomposition (UMOEA/D), and compares the proposed algorithm with MOEA/D and NSGA-II on some scalable test problems with three to five objectives. UMOEA/D adopts the uniform design method to set the aggregation coefficient vectors of the subproblems. Compared with MOEA/D, distribution of the coefficient vectors is more uniform over the design space, and the population size neither increases nonlinearly with the number of objectives nor considers a formulaic setting. The experimental results indicate that UMOEA/D outperforms MOEA/D and NSGA-II on almost all these many-objective test instances, especially on problems with higher dimensional objectives and complicated Pareto set shapes. Experimental results also show that UMOEA/D runs faster than NSGA-II for the problems used in this paper. In additional, the results obtained are very competitive when comparing UMOEA/D with some other algorithm on the multiobjective knapsack problems.
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A modified tri-axial electrospinning process was developed for the generation of a new type of pH-sensitive polymer/lipid nanocomposite. The systems produced are able to promote both ...dissolution and permeation of a model poorly water-soluble drug. First, we show that it is possible to run a tri-axial process with only one of the three fluids being electrospinnable. Using an electrospinnable middle fluid of Eudragit S100 (ES100) with pure ethanol as the outer solvent and an unspinnable lecithin-diclofenac sodium (PL–DS) core solution, nanofibers with linear morphology and clear core/shell structures can be fabricated continuously and smoothly. X-ray diffraction proved that these nanofibers are structural nanocomposites with the drug present in an amorphous state. In vitro dissolution tests demonstrated that the formulations could preclude release in acidic conditions, and that the drug was released from the fibers in two successive steps at neutral pH. The first step is the dissolution of the shell ES100 and the conversion of the core PL–DS into sub-micron sized particles. This frees some DS into solution, and later the remaining DS is gradually released from the PL–DS particles through diffusion. Ex vivo permeation results showed that the composite nanofibers give a more than twofold uplift in the amount of DS passing through the colonic membrane as compared to pure DS; 74% of the transmitted drug was in the form of PL–DS particles. The new tri-axial electrospinning process developed in this work provides a platform to fabricate structural nanomaterials, and the core–shell polymer-PL nanocomposites we have produced have significant potential applications for oral colon-targeted drug delivery.
A modified tri-axial electrospinning is demonstrated to create a new type of core–shell pH-sensitive polymer/lipid nanocomposites, in which an electrospinnable middle fluid is exploited to support the un-spinnable outer and inner fluids. The structural nanocomposites are able to provide a colon-targeted sustained release and an enhanced permeation performance of diclofenac sodium. The developed tri-axial process can provide a platform for fabricating new structural nanomaterials with high quality. The strategy of a combined usage of polymeric excipients and phospholipid in a core–shell format should provide new possibilities of developing novel drug delivery systems for efficacious oral administration of poorly-water soluble drugs.
•The displacement field is given to further understand the deformation and oscillation of crack faces.•The maximum energy release rate criterion is presented to discuss about whether the crack can ...propagate through kinking out of the interface.•Crack kinking can be prohibited in the proposed artificial periodic structures with local resonators.
In this study, the propagation and kinking of an interface crack between two dissimilar artificial periodic structures with local resonators is investigated. By Fourier transform, the dynamic fracture problem is derived as an equation with Wiener–Hopf type. An additional band gap can be created by local resonators. During the dynamic failure, elastic waves will be excited continuously from the crack tip and result in the energy dissipation. Moreover, the energy release ratio which characterizes the fracture resistance is obtained. The meta-arrest property of the artificial periodic structure with local resonators is illustrated. Based on inverse Fourier transform, the displacement field is given to further understand the deformation and oscillation of crack faces. Based on the crack-tip field, the maximum energy release rate criterion is presented to discuss about whether the crack can propagate through kinking out of the interface. Comparing with the model without local resonators, we find that crack kinking can be prohibited in the proposed artificial periodic structures. Finally, finite element simulation and experiment are performed to show the good agreement with the theoretical predictions.
•The energy release ratio which denotes the crack splitting resistance is derived and the corresponding radiated waves are discussed•The energy barrier before the stable propagates is larger, which ...means that the ability to resist the crack speed is enhanced•The lower energy release ratio in the subsonic and supersonic regions indicates that the elastic wave metamaterials with local resonators has a better crack resistance and shows the meta-arrest property.
In this study, the dynamic effective mass and effects of local resonators on the crack growth are investigated. Based on Wiener-Hopf method and factorization using Cauchy-type integral, the energy release ratio which denotes crack splitting resistance is derived and the corresponding radiated waves are discussed. The results show that at variance with traditional periodic mass-spring lattice chain, the radiated energy of the present elastic wave metamaterial with local resonators is more sensitive to low crack speeds. The energy barrier before the stable propagates is larger, which means that the ability to resist the crack speed is enhanced. The lower energy release ratio in the subsonic and supersonic regions indicates that the elastic wave metamaterials with local resonators has better crack resistance and shows the meta-arrest property. The present results might have potential application to improve the crack resistance of advanced materials and structures.
In the paper, Ti6Al4V substrates have been pretreated with sodium hydroxide (NaOH) solution. After that, hydroxyapatite (HA) is deposited on the Ti6Al4V surface by electrochemical methods. The aim of ...this study is to investigate the influences of current density on the coating compositions, microstructure, and bonding strength between coating and substrate. The results show that the composition of the HA coating and the grain size remained relatively unchanged with the variations of current density during electrochemical deposition. When the value of electrochemical deposition current density is 2.5mA/cm2, the HA coating has the largest thickness, and the bonding strength is near 18MPa. The experiments of the samples being immersed into simulated body fluid estimate that the HA coating promotes the deposition of calcium phosphate. The formation mechanism of HA coating on modified Ti6Al4V deposited by electrochemical method is discussed.
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•Immerse Ti6Al4V alloy in NaOH solution•Hydroxyapatite coatings were deposited by electrochemical deposition method.•We examine changes of composition, microstructure and bonding strength of coating.•Lamellar HA crystals form on the modified Ti6Al4V surfaces.•Formation mechanisms of coating on modified substrate surface were discussed.
As emerging artificial structures, elastic wave metamaterials can show some unique properties in special frequency regions. In this study, the elastic wave scattering by a pair of parallel ...semi-infinite cracks in mechanical metamaterials with local resonators is studied. According to the discrete Wiener–Hopf method, the far field displacement solution is obtained. At the same time, the dynamic negative effective mass and band gaps can be observed with local resonators. Our attention is focused on how the internal microstructure affects the crack faces. Numerical results show that because of the stop band, the crack can be prevented from being disturbed by incident waves in specific frequency regions. As a result, the possibility of crack initiation and instability propagation is reduced considerably. This present work is expected to provide a way to improve arrest performance of elastic waves metamaterials.
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