Development of controlled release bi-layered tablets containing oxycodone hydrochloride

Oxycodone hydrochloride is a semi-synthetic opioid agonist that provides very effective relief for moderate to severe pain in cancer and post-operative patients. Controlled release oxycodone formulations have been studied to enhance the therapeutic effect by providing constant release over the whole dosing interval and improve patient’s convenience by reducing the frequency of administration as well.

An analytic model for transient heat conduction in bi-layered structures with flexible serpentine heaters

Uniform heating of complex surfaces,especially non-developable surfaces,is a crucial problem that traditional rigid heaters cannot solve.Inspired by flexible electronic devices,a novel design for the stretchable heating film is proposed with the flexible serpentine wire embedded in the soft polymer film,which can be attached to non-developable surfaces conformally.It provides a new way for the stretchable heaters to realize uniform heating of complex surfaces.However,the thermal field of flexible serpentine heaters(FSHs)depends on the configurations of the embedded serpentine heating wire,which requires accurate theoretical prediction of real-time temperature distribution.Therefore,the analytical model for the transient heat conduction in FSHs is solved by the separation of variables method and validated by the finite element analysis(FEA)in this paper.Based on this model,the effects of the geometric parameters,such as the radius and the length of the serpentine heaters,on the thermal uniformity are systematically investigated.This study can help to design and fabricate flexible heaters with uniform heating in the future.

High-Efficiency Wide-Band Cross-Polarization Conversion Using Bi-layered Metal Hole Pairs

We present a polarization converter composed of bi-layered metal films perforated with rectangle hole pairs in each film. The proposed converter can convert the polarization of an incident linearly-polarized electromagnetic wave to its orthogonal direction with high efficiency and large bandwidth in the infrared or microwave regions.To make sure of the mechanism of polarization conversion, the current and electric-field distributions at different resonant frequencies are analyzed. It is found that the cross-polarized transmission is due to the near-field coupling between hole pairs in neighboring metal films. Finally, a prototype of the proposed converter is fabricated and measured in the microwave region. Good agreement between the experimental and simulated results is obtained.

A biomimetic bi-layered tissue engineering scaffolds for osteochondral defects repair

Osteochondral defects are most commonly characterized by damages to both cartilage and underlying subchondral bone tissues,thus developing bi-layered scaffold that can concurrently regenerate these two specific lineages becomes challenge.In this study,the highly biomimetic bi-layered scaffolds were successfully prepared using human-like-collagen(HLC),hyaluronan(HA)and nano hydroxyapatite(HAP)particles,combined with"liquid phase synthesis"technology,freeze-drying and chemical crosslinking techniques,which was simulated the composition of natural extracellular matrix to repair osteochondral defects.This novel bilayer osteochondral graft had a seamlessly integrated layer structure,suitable pore size,high levels of porosity,and excellent mechanical properties.In vitro cell experiments of the bilayer scaffold indicated that the scaffold could promote the proliferation and adhesion of human bone marrow mesenchymal stem cells.In vivo osteochondral defects and micro-CT experiment revealed that bilayer scaffolds showed complete closure of the defect.Histology confirmed collagen and glycosaminoglycans were deposited in the new matrix of hyaline cartilage and bone in the bilayer scaffold group.Therefore,the developed bionic bilayer scaffold enhanced the regeneration of hyaline cartilage through subchondral bone formation and lateral host-tissue integration.In conclusion,this bilayer scaffold based on HLC could be used as the desired strategy for osteochondral defects regeneration.

Characterization of Micro and Nano-Scaled Co/Ni Bi-Layered Films Electrodeposited Under Influence of Magnetic Field:Effects on Structure and Morphology

In this study,the possibility of obtaining micro and nano-scaled Co/Ni bi-layered films by use of the electrochemical method was investigated.The electrodeposition process was performed with presence and absence of a uniform external magnetic field up to 1T to examine its influence on structure and morphology of the obtained thin films. Afterwards,each sample was annealed under high magnetic field with strength up to 12 T at 623 K,what allowed compare and determine the changes in morphology and structure,before and after heat treatment.The Co/Ni bi-layered thin films were deposited onto an indium-doped tin oxide(ITO)-coated conducting glass substrate from sulfate baths with boric acid as an additive.The results show drastic changes in the morphology between macro and nano-scaled films which were strongly affected by an introduction of the magnetic field to the electrodeposition process.The annealing process allowed to determine the nucleus transition and showed that under the high temperature treatment it is possible to control the growth mode as well as the phase composition changes.

Analysis of the in vitro degradation and the in vivo tissue response to bi-layered 3D-printed scaffolds combining PLA and biphasic PLA/bioglass components--Guidance of the inflammatory response as basis for osteochondral regeneration

The aim of the present study was the in vitro and in vivo analysis of a bi-layered 3D-printed scaffold combining a PLA layer and a biphasic PLA/bioglass G5 layer for regeneration of osteochondral defects in vivo Focus of the in vitro analysis was on the(molecular)weight loss and the morphological and mechanical variations after immersion in SBF.The in vivo study focused on analysis of the tissue reactions and differences in the implant bed vascularization using an established subcutaneous implantation model in CD-1 mice and established histological and histomorphometrical methods.Both scaffold parts kept their structural integrity,while changes in morphology were observed,especially for the PLA/G5 scaffold.Mechanical properties decreased with progressive degradation,while the PLA/G5 scaffolds presented higher compressive modulus than PLA scaffolds.The tissue reaction to PLA included low numbers of BMGCs and minimal vascularization of its implant beds,while the addition of G5 lead to higher numbers of BMGCs and a higher implant bed vascularization.Analysis revealed that the use of a bi-layered scaffold shows the ability to observe distinct in vivo response despite the physical proximity of PLA and PLA/G5 layers.Altogether,the results showed that the addition of G5 enables to reduce scaffold weight loss and to increase mechanical strength.Furthermore,the addition of G5 lead to a higher vascularization of the implant bed required as basis for bone tissue regeneration mediated by higher numbers of BMGCs,while within the PLA parts a significantly lower vascularization was found optimally for chondral regeneration.Thus,this data show that the analyzed bi-layered scaffold may serve as an ideal basis for the regeneration of osteochondral tissue defects.Additionally,the results show that it might be able to reduce the number of experimental animals required as it may be possible to analyze the tissue response to more than one implant in one experimental animal.

3D-printed,bi-layer,biomimetic artificial periosteum for boosting bone regeneration

Periosteum,a membrane covering the surface of the bone,plays an essential role in maintaining the function of bone tissue—and especially in providing nourishment and vascularization during the bone regeneration process.Currently,most artificial periostea have relatively weak mechanical strength and a rapid degradation rate,and they lack integrated angiogenesis and osteogenesis functions.In this study,a bi-layer,biomimetic,artificial periosteum composed of a methacrylated gelatin–nano-hydroxyapatite(GelMA-nHA)cambium layer and a poly(N-acryloyl 2-lycine)(PACG)-GelMA-Mg^(2+)fibrous layer was fabricated via 3D printing.The GelMA-nHA layer is shown to undertake the function of improving osteogenic differentiation of rat bone marrow mesenchymal stem cells with the sustainable release of Ca^(2+) from nHA nanoparticles.The hydrogen-bonding-strengthened P(ACG-GelMA-L)-Mg^(2+)hydrogel layer serves to protect the inner defect site and prolong degradation time(60 days)to match new bone regeneration.Furthermore,the released magnesium ion exhibits a prominent effect in regulating the polarization phenotype of macrophage cells into theM2 phenotype and thus promotes the angiogenesis of the human umbilical vein endothelial cells in vitro.This bi-layer artificial periosteum was implanted into a critical-sized cranial bone defect in rats,and the 12-week post-operative outcomes demonstrate optimal new bone regeneration.

Fabrication of a Bi-layer Tubular Scaffold Consisted of a Dense Nanofibrous Inner Layer and a Porous Nanoyarn Outer Layer for Vascular Tissue Engineering

Recent years, it has attracted more attentions to increase the porosity and pore size of nanofibrous scaffolds to provide the for the cells to grow into the small-diameter vascular grafts. In this study, a novel bi-layer tubular scaffold with an inner layer and an outer layer was fabricated. The inner layer was random collagen/poly （ L-lactide-co-caprolactone ） I P （ LLA- CL） ] nanofibrous mat fabricated by conventional electrospinning and the outer layer was aligned collagen/P （LLA-CL） nanoyarns prepared by a dynamic liquid dectrospinning method. Fourier transform infrared spectroscopy （FTIR） was used to characterize the chemical structure. Scanning electron microscopy （ SEM ） was employed to observe the morphology of the layers and the cross- sectioned bi-layer tubular scaffold. A liquid displacement method was employed to measure the porosities of the inner and outer layers. Stress-strain curves were obtained to evaluate the mechanical properties of the two different layers and the bi-layer membrane. The diameters of the nanofibers and the nanoyarns were （480 ± 197 ） nm and （ 19.66 ± 4.05 ） μm, respectively. The outer layer had a significantly higher porosity and a larger pore size than those of the inner layer. Furthermore, the bi-layer membrane showed a good mechanical property which was suitable as small-diameter vascular graft. The results indicated that the bi-layer tubular scaffold had a great potential application in small vascular tissue engineering.

Developments of Cr-Si and Ni-Cr Single-Layer Thin-Film Resistors and a Bi-Layer Thin-Film Resistor with Adjustable Temperature Coefficient of Resistor

At first, Cr-Si (28 wt% Cr, 72 wt% Si) and Ni-Cr (80 wt% Ni, 20 wt% Cr) thin-film materials were deposited by using sputtering method at the same parameters, and their physical and electrical properties were investigated. The resistances of Cr-Si and Ni-Cr thin-film resistors decreased with the increase of deposition time (thickness) and their resistivity had no apparent variations as the deposition time increased. The temperature coefficient of resistance (TCR) of single-layer Cr-Si thin-film resistors was negative and the TCR value of single-layer Ni-Cr thin-film resistors was positive. For that, we used Cr-Si thin films as upper (or lower) layer and Ni-Cr thin films as lower (upper) layer to investigate a bi-layer thin-film structure. The deposition time of Ni-Cr thin films was fixed at 10 min and the deposition time of Cr-Si thin films was changed from 10 min to 60 min. We had found that as Cr-Si thin films were used as upper or lower layers they had similar deposition rates. We had also found that the thickness and stack method of Cr-Si thin films had large effects on the resistance and TCR values of the bi-layer thin-film resistors.

Deep Reinforcement Learning Based Bi-layer Optimal Scheduling for Microgrids Considering Flexible Load Control

In this paper,the bi-layer scheduling method for microgrids,based on deep reinforcement learning,is proposed to achieve economic and environmentally friendly operations.First,considering the uncertainty of renewable energy,the framework of day-ahead and intra-day scheduling is established,and the implementation scheme for both price-based and incentive-based demand response(DR)for the flexible load is determined.Then,comprehensively considering the operating characteristics of the microgrid in the day-ahead and intra-day time scales,a bi-layer scheduling model of the microgrid is established.In terms of algorithms,since day-ahead scheduling has no strict requirement for dispatching time,the particle swarm optimization(PSO)algorithm is used to optimize the time-of-use electricity price and distributed power output for the next day.Considering the environmental fluctuations and requirements for rapidity of intra-day online scheduling,the deep reinforcement learning(DRL)algorithm is adopted for optimization.Finally,based on the data from the actual microgrid,the rationality and effectiveness of the proposed scheduling method is verified.The results show that the proposed bi-layer scheduling based on the PSO and DRL algorithms achieves the optimization of scheduling cost and calculation speed,and is suitable for microgrid online scheduling.

Mechanical Analyses of Rails and Panels in a Rectangular Electromagnetic Rail Launcher

In the present work,rails and panels in a rectangular electromagnetic rail launcher were simulated as finite-length bi-layer elastic foundation beams. Mechanical equilibrium equations were established for these bi-layer beams under the electromagnetic and contact forces between armatures and rails. With the application of Generalized Krylov function,analytical expressions of rails( upper beam) and panels( lower beam) 'deformation and stress were generated. The analytical results agree well with ANSYS calculations even in the presence of electromagnetic and armature's forces,a strong indication of the reliability of the analytical approach. The current work lays the foundation for mechanical analyses of rectangular electromagnetic rail launchers,and offers help in future designs and calculations in marine,aerospace,and civil engineering.

Optical beam splitting and asymmetric transmission in bi-layer metagratings

In this work, inspired by advances in twisted two-dimensional materials, we design and study a new type of optical bi-layer metasurface system, which is based on subwavelength metal slit arrays with phase-gradient modulation, referred to as metagratings(MGs). It is shown that due to the found reversed diffraction law, the interlayer interaction that can be simply adjusted by the gap size can produce a transition from optical beam splitting to high-efficiency asymmetric transmission of incident light from two opposite directions. Our results provide new physics and some advantages for designing subwavelength optical devices to realize efficient wavefront manipulation and one-way propagation.

3D printed biomimetic epithelium/stroma bilayer hydrogel implant for corneal regeneration

Corneal regeneration has always been a challenge due to its sophisticated structure and undesirable keratocyte-fibroblast transformation. Herein, we propose 3D printing of a biomimetic epithelium/stroma bilayer implant for corneal regeneration. Gelatin methacrylate (GelMA) and long-chain poly(ethylene glycol) diacrylate (PEGDA) are blended to form a two-component ink, which can be printed to different mechanically robust programmed PEGDA-GelMA objects by Digital Light Processing (DLP) printing technology, due to the toughening effect of crystalline crosslinks from long-chain PEGDA on GelMA hydrogel after photo-initiated copolymerization. The printed PEGDA-GelMA hydrogels support cell adhesion, proliferation, migration, meanwhile demonstrating a high light transmittance, and an appropriate swelling degree, nutrient permeation and degradation rate. A bi-layer dome-shaped corneal scaffold consisting of rabbit corneal epithelial cells (rCECs)-laden epithelia layer and rabbit adipose-derived mesenchymal stem cells (rASCs)-laden orthogonally aligned fibrous stroma layer can be printed out with a high fidelity and robustly surgical handling ability. This bi-layer cells-laden corneal scaffold is applied in a rabbit keratoplasty model. The post-operative outcome reveals efficient sealing of corneal defects, re-epithelialization and stromal regeneration. The concerted effects of microstructure of 3D printed corneal scaffold and precisely located cells in epithelia and stroma layer provide an optimal topographical and biological microenvironment for corneal regeneration.

Effect of substrate temperature on the properties of deep ultraviolet transparent conductive ITO/Ga_2O_3 films

ITO/Ga2O3 bi-layer films were deposited on quartz glass substrates by magnetron sputtering. The effect of substrate temperature on the structure, surface morphology, optical and electrical properties of ITO/Ga2O3 films was investigated by an X-ray diffractometer, a scanning electron microscope, a double beam spectrophotometer and the Hall system, respectively. The structural characteristics showed a dependence on substrate temperature. The resistivity of the films varied from 6.71 × 10^-3 to 1.91× 10^-3 Ω·cm as the substrate temperature increased from 100 to 350℃. ITO （22 nm）/Ga2O3 （50 nm） films deposited at 300℃ exhibited a low sheet resistance of 373.3 Ω/□ and high deep ultraviolet transmittance of 78.97% at the wavelength of 300 nm.