In vitro and in vivo evaluations of Mg-Zn-Gd alloy membrane on guided bone regeneration for rabbit calvarial defect

To develop a biodegradable membrane with guided bone regeneration(GBR),a Mg-2.0Zn-1.0Gd alloy(wt.%,MZG)membrane with Ca-P coating was designed and fabricated in this study.The microstructure,hydrophilicity,in vitro degradation,cytotoxicity,antibacterial effect and in vivo regenerative performance for the membrane with and without Ca-P coating were evaluated.After coating,the membrane exhibited an enhance hydrophilicity and corrosion resistance,showed good in vitro cytocompatibility upon MC3T3E-1 cells,and exhibited excellent antibacterial effect against E.coli,Staphylococcus epidermis and Staphylococcus aureus,simultaneously.In vivo experiment using the rabbit calvarial defect model confirmed that Ca-P coated MZG membrane underwent progressive degradation without inflammatory reaction and significantly improved the new bone formation at both 1.5 and 3 months after the surgery.All the results strongly indicate that MZG with Ca-P coating have great potential for clinical application as GBR membranes.

Preparation Methods and Properties of PdCu Alloy Membrane for Hydrogen Transition

Pd and Pd alloy membranes are of increasing interest for hydrogen separation and purification due to their good thermal stability, high permeability and perfect selectivity. PdCu alloy (60wt% Pd) membranes have similar hydrogen permeability compared with PdAg alloy; meanwhile, it is cheaper than PdAg alloy. Furthermore, it has been reported that PdCu membrane has better resistance to poisoning and deactivation by H 2 S impurity. This paper reviews the properties and manufacturing methods of PdCu alloy membrane, finally, introduced some achievement made by us on PdCu alloy membrane.

Progress of Palladium Alloy Membranes in Hydrogen Energy

Palladium and palladium alloy membranes have attracted wide attention in hydrogen permeation areas for their excellent permeability, perm -selectivity and thermal stability. This paper review the principle of hydrogen permeation, type of alloys and the fabrication methods. At last, the progress and achievements on palladium alloy membranes by Northwest Institute for Non-Ferrous Metal Research are emphasized.

Study on repairing canine mandibular defect with porous Mg-Sr alloy combined with Mg-Sr alloy membrane

To discuss the feasibility of the application of porous Mg-Sr alloy combined with Mg-Sr alloy membrane in the repair of mandibular defects in dogs.The second and third mandibular premolars on both sides were extracted from six dogs.The model of mandible buccal fenestration bone defects were prepared after the sockets healed.Twelve bone defects were randomly divided into groups A and B,then Mg-Sr alloy was implanted in bone defects of group A and covered by Mg-Sr alloy membrane while Mg-Sr alloy was implanted in bone defects of group B and covered by mineralized collagen membrane.Bone defects observed on cone beam computed tomographic images and comparing the gray value of the two groups after 4,8 and 12 weeks.After 12 weeks,the healing of bone defects were evaluated by gross observation,X-ray microscopes and histological observation of hard tissue.Bone defects in each group were repaired.At 8 and 12 weeks,the gray value of group A was higher than that of group B(P<0.05).At 12 weeks,the bone volume fraction of group A was higher than that of group B(P<0.05).The newly woven bone in group A is thick and arranged staggered,which was better than that of group B.Porous Mg-Sr alloy combined with Mg-Sr alloy membrane could further promote the repair of mandibular defects,and obtain good osteogenic effect.

Microstructural development of vanadium-nickel crystalline alloy membranes

V85Ni15(at%)alloy was proposed as a promising candidate for hydrogen separation membranes.To date,investigations of V85Ni15 alloy have concentrated on hydrogen permeation characteristics,and little work has been done on the microstructural development.In the present study,various fabrication and heat-treatment techniques were used to develop different microstructures which would then be tailored to achieve a desired candidate for acceptable mechanical stability while maintaining high hydrogen permeability.The arc-melted(AM)V85Ni15 alloy are supersaturated solid solution with dendritic segregation of Ni-solute atoms.Cold rolling(CR)followed by annealing at 1050℃and 850℃can produce a two-phase(V+σ)microstructure and a three-phase(V+σ+NiV3)microstructure,respectively.Very fine two-phase microstructure obtained at 1050℃involves a simultaneous reaction of second-phase precipitation and V-matrix recrystallization.Sigma phase is formed via primary precipitation,while NiV3 phase is formed by peritectoidal reaction.When AMCR samples were homogenized at1250℃for 2 h and sequential heat-treated at 850℃or900℃for 2 h,precipitation-strengthening microstructure is obtained:large grain structure of V-matrix with uniform distribution of second-phase particles produced by recrystallization and grain growth followed by precipitation process.

Palladium-based Membrane Applications for Hydrogen Purification

It describes the purification of hydrogen isotopes, separation with the preparation of palladium-based membrane's technology, types, application, advantages and disadvantages of palladium in this article. Due to excellent comprehensive properties palladium composite membrane will become the future direction of development. At the same time it will develop preparation methods of the membrane support body with high mechanical strength and heat resistance and low-cost and palladium-based membrane. Also it will explore high service life and high transmittance of novel composite membrane.

Fundamental Laws of Structure and Form Changing of Palladium Loading with Hydrogen

There are reviewed some experimental results on metal-hydrogen and PdH x -hydrogen interaction. There is experimentally shown that penetration of hydrogen in palladium is accompanied with strong and micro structural effects, as well as grain shifts, etc. Moreover, the hydrogen saturation of palladium causes form-changing (bending) of palladium plate. These effects, undoubtedly, must be taken in account in technologies of low-temperature diffusion membrane apparatus exploitation.