Anti-inflammatory and in vitro bone formation effects of Garcinia mangostana L. and propolis extracts

Food Science and Biotechnology - The purpose of this study was to determine the anti-inflammatory and in vitro bone formation effects of Garcinia mangostana L. (mangosteen) and propolis extracts....     

Physical modification of polypropylene: preparation of fibres dyeable with disperse dyes

Published literature from the past 30 years concerning the removal of dyes from textile effluent has been reviewed. The relationship between the bioelimination by activated sewage sludge and the molecular structure of anionic, water-soluble dyes has been examined. Bioelimination of many commercially available dyes as a mechanism for decolorising textile waste waters has been shown to be an inefficient process. However, the information collated will be used as the basis for development of novel reactive dyes for potential commercial application.     

Structure–tensile property relationship of knitted fabric composites

This paper reports some further studies on the tensile properties of plain weft knitted DuPont Kevlar fiber fabric reinforced epoxy matrix composites. One aim of this work is to investigate systematically the anisotropy of knitted fabric composites. Tensile tests were conducted at different off‐axial angles (0°, 30°, 45°, 60° and 90°) with respect to the wale direction. Fracture modes corresponding to this off‐axial variation were clearly identified. The elastic modulus and tensile strength were found to be the highest in the wale direction (0°), but decreased gradually towards the course direction (90°). This anisotropic study was carried out on both single layered and multilayered (four layered) knitted fabric composites. Another aim is to study the effect of specimen width (or number of loops per specimen width) on the tensile properties. This study indicated an optimum number of loops per sample width required to obtain meaningful tensile test results. Further, edge effect on the tensile properties of the knitted fabric composites was also investigated in the paper. This was achieved through comparative studies on cut and uncut four layered specimens. In the cut specimens the continuity of the yarns is lost at the cut edges, which show a marginal variation in the properties compared with the uncut specimens where the yarns are continuous throughout the specimen. Finally, a study was also carried out to investigate the effect of loop size (or stitch density) on the tensile strength and stiffness of the single layered composites.     

Limonene transport and mechanical properties of EVOH and nylon 6,6 films as influenced by RH

The transport properties of d‐limonene through ethylene vinyl alcohol copolymers (EVOH) and nylon 6,6 films as functions of relative humidity (RH) and temperature were studied. Permeation properties of these polymers were strongly influenced by temperature and RH. Compared to the EVOH films, the nylon 6,6 film had much greater limonene permeability. Mechanical property studies indicated that both the tensile modulus and yield strength of the EVOH films decreased with an increase in RH. The polymer changed from being stiff and brittle at low RH to being soft and ductile at high RH. In addition, ethylene content and orientation were found to affect the transport and mechanical properties of limonene through EVOH polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1949–1957, 2001     

Enhanced Bone Regeneration in Variable-Type Biphasic Ceramic Phosphate Scaffolds Using rhBMP-2

Our aim was to investigate the bone regeneration capacity of powder-type biphasic ceramic scaffold (BCP powder), block-type BCP (BCP block), and collagen-added block-type BCP (BCP collagen) with different concentrations of recombinant human bone morphogenetic protein 2 (rhBMP-2) in an animal model. Four rabbits were assigned to each of the following groups: no graft + rhBMP-2 (0.1/0.2 mg/mL), BCP powder + rhBMP-2 (0.1/0.2 mg/mL), BCP block + rhBMP-2 (0.1/0.2 mg/mL), and BCP collagen + rhBMP-2 (0.1/0.2 mg/mL), i.e., a total of 32 rabbits. Polycarbonate tubes (Φ 7 mm × 5 mm) for supporting scaffolds were fixed into a 7 mm round border. Subsequently, 0.1 mL of rhBMP-2 solutions with different concentrations was injected into the tubes. Both radiological and histomorphometric analyses showed that osteogenesis was not enhanced by increasing the concentration of rhBMP-2 in all groups at both 3 and 6 weeks. Radiological analysis showed that bone formation was higher in the BCP collagen group than in the BCP powder and BCP block groups at both rhBMP-2 concentrations at 3 weeks. rhBMP-2 enhanced bone formation; however, as the concentration increased, bone formation could not be enhanced infinitely. Collagen-added alloplastic graft material may be useful for mediating rapid bone formation in initial stages.     

Blends of ethylene 1‐octene copolymer synthesized by Ziegler–Natta and metallocene catalysts. II. Rheology and morphological behaviors

The rheological and morphological behaviors of commercially available three binary blends of ethylene 1‐octene copolymer (EOC) regarding the melt index (MI), density and comonomer contents, one component made by the Ziegler–Natta and the other by the metallocene catalysts, were investigated to elucidate miscibility and phase behavior. Miscibility of the EOCs blend in a melt state was related to the value of the MI, density, and comonomer content. If the comonomer contents are similar, then the melt viscosity is weight average value, otherwise it is positively or negatively deviated. The microtomed surface prepared by two different cooling processes—one is fast cooling and the other is slow cooling—indicated that all the blends were not homogenous regardless the density, MI, and comonomer content. The Ziegler–Natta catalyzed EOCs exhibited bigger spherulitic diameter and larger ring space than those of the metallocene EOCs prepared by a cooling process. The blends consisting of similar MI showed banded spherulites with different diameter, whereas the blend consisting of different MI and density takes place of explicit phase separation and phase inversion at 1 : 1 blend composition. The melt rheology appeared to influence the mechanical and film properties in the solid state. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1950–1964, 2000     

Toughening of PP/EPDM blend by compatibilization

To improve the mechanical properties of blends of polypropylene (PP) and terpolymer of ethylene–propylene–diene (EPDM), a triblock copolymer, (PP‐g‐MAH)‐co‐[PA‐6,6]‐co‐(EPDM‐g‐MAH), was synthesized by coupling reaction of maleic anhydride (MAH)‐grafted PP (PP‐g‐MAH), EPDM‐g‐MAH, and PA‐6,6. The newly prepared block copolymer brought about a physical interlocking between the blend components, and imparted a compatibilizing effect to the blends. Introducing the block copolymer to the blends up to 5 wt % lead to formation of a β‐form crystal. The wide‐angle X‐ray diffractograms measured in the region of 2θ between 10° and 50° ascertained that incorporating the block copolymer gave a new peak at 2θ = 15.8°. The new peak was assigned to the (300) plane spacings of the β‐hexagonal crystal structure. In addition, the block copolymer notably improved the low‐temperature impact property of the PP/EPDM blends. The optimum usage level of the compatibilizer proved to be 0.5 wt %. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1267–1274, 2000