Electrical, optical, and electrochemical performances of phosphate-glasses-doped with ZnO and CuO and their composite with polyaniline.

Phosphate-based glasses (PBG) with appropriate doping agents have been used as solid electrolytes in solid-state ionic devices. Therefore, more light was shed on the electrical, optical, and electrochemical behavior of the phosphate-based glasses (PBG), containing ZnO or CuO in the absence and existence of conductive polyaniline (PANI), since no publications are available concerning this work. The glass samples were prepared by the rapid quenching method, then mixing phosphate glass and polyaniline (PANI) with metal oxide (ZnO, CuO). They were characterized by different techniques; diffuse reflectance spectrophotometer (DRS), broadband dielectric spectrometer (BDS), cyclic voltammetry (CV), and charge-discharge techniques. In the DRS study, the direct and indirect band gap were calculated from Tauc's relationship where CuO-doped glasses have higher values than ZnO-doped glasses. In the BDS study, the permittivity of all glass compositions decreased while AC conductivity increased with increasing frequency. AC conductivity of PBG doped with metal oxides and mixed with PANI exhibited semiconducting features (6.8 × 10-4 S/cm). Further, these composites exhibited lower loss tangent (0.11), and giant permittivity (186,000) compared to the pure PBG. Also, the electrochemical study exhibited that the composite with 7% CuO content has the highest specific capacitance value (82.3 F/g at 1.0 A/g) which increased to about 113% of its first cycle and then decreased to about 55% after 2500 cycles and finally increased again to 77% after 4500 cycles, indicating its good stability. The combination of optical, electrical, and electrochemical features of these composites suggests their use for energy generation and storage devices.

Structural Changes, Electrophoretic Pattern, and Quality Attributes of Camel Meat Treated with Fresh Ginger Extract and Papain Powder.

Camel is a valuable source of meat for African and Asian countries; however, the most important problem associated with camel meat is its extreme toughness. This toughness has been attributed to its contents of connective tissue, which become more crossly linked in old animals. The toughness of camel meat decreases the consumer acceptance of this meat and reduces its chances of being utilized as a raw material for further processing into meat products. Ginger and papain were used in the current study as tenderizing enzymes, and the structural changes, electrophoretic pattern, physicochemical characteristics, and sensory scores of the treated meat were examined. The treatment of camel meat with ginger and papain resulted in marked destructive changes in the connective tissue and myofibers, and a reduction in the protein bands, with a consequent improvement in its tenderness. All the enzyme-treated samples exhibited significant increases in the protein solubility, with significant decreases in the shear-force values. Moreover, an improvement in the sensory scores of the raw and cooked meat and a reduction in the bacterial counts after the treatments were recorded. Ginger and papain induced a significant improvement in the physicochemical characteristics, sensory attributes, and bacterial counts of the camel meat; therefore, these materials can be utilized by meat processors to boost the consumer acceptance of this meat, and to increase its suitability as a raw material for further meat processing.

Taking Hydroxyapatite-Coated Titanium Implants Two Steps Forward: Surface Modification Using Graphene Mesolayers and a Hydroxyapatite-Reinforced Polymeric Scaffold.

Coating with hydroxyapatite (HAP) presents a mainstream strategy for rendering bioinert titanium implants bioactive. However, the low porosity of pure HAP coatings does not allow for the infiltration of the surface of the metallic implant with the host cells. Polymeric scaffolds do enable this osseointegration effect, but their bonding onto titanium presents a challenge because of the disparity in hydrophilicity. Here, we demonstrate the inability of a composite scaffold composed of carbonated HAP (CHAP) nanoparticles interspersed within electrospun ε-polycaprolactone (PCL) nanofibers to bind onto titanium. To solve this challenge, an intermediate layer of graphene nanosheets was deposited in a pulsed laser deposition process, which facilitated the bonding of the scaffold. The duration of the deposition of graphene (0, 5, 10, 15, and 20 min) and the thickness of its mesolayer affected numerous physical and chemical properties of the material, including the surface atomic proportion of carbon bonds, the orientation and interlinking of the polymeric nanofibers, and the surface roughness, which increased in direct proportion with the thickness of the graphene mesolayer. Because the polymeric scaffold did not adhere onto the surface of pure titanium, no cells were detected growing on it in vitro. In contrast, human fibroblasts adhered, spread, and proliferated well on all the substrates sputtered with both graphene and the composite scaffold. The orientations of cytoskeletal filopodia and lamellipodia were largely determined by the topographic orientation of the nanofibers and the geometry of the surface pores, attesting to the important effects that the presence of a scaffold has on the cellular behavior. The protection of titanium from corrosion in the simulated body fluid (SBF) was enhanced by coating with graphene and the composite scaffold, with the most superior resistance to the attack of the corrosive ions being exhibited by the substrate subjected to the shortest duration of the graphene deposition because of the highest atomic ratio of C-C to C-O bonds detected in it. Overall, some properties of titanium, such as roughness and wettability, were improved monotonously with an increase in the thickness of the graphene mesolayer, while others, such as cell viability and resistance to corrosion, required optimization, given that they were diminished at higher graphene mesolayer thicknesses. Nevertheless, every physical and chemical property of titanium analyzed was significantly improved by coating with graphene and the composite scaffold. This type of multilayer design evidently holds a great promise in the design of biomaterials for implants in orthopedics and tissue engineering.

Physical, electrochemical and biological evaluations of spin-coated ε-polycaprolactone thin films containing alumina/graphene/carbonated hydroxyapatite/titania for tissue engineering applications.

Composite structures are at the frontier of materials science and engineering and polymeric/ceramic composites present one of their most prospective subsets. Prior studies have shown both improvements and deteriorations of properties of polymers upon the addition of ceramic phases to them, but not many studies have dealt with the direct comparison of chemically distinct inorganic additives. The goal of this study was to compare the properties of ε-polycaprolactone (PCL) thin films supplemented with alumina, graphene, carbonated hydroxyapatite or titania particles, individually, in identical amounts (12 wt%). The composite films were analyzed for their phase composition, grain size, morphology, surface roughness, porosity, cell response, mechanical properties and electrochemical performance. Each additive imparted one or more physical or biological properties onto PCL better than others. Thus, alumina increased the microhardness of the films better than any other additive, with the resulting values exceeding 10 MPa. It also led to the formation of a composite with the least porosity and the greatest stability to degradation in simulated body fluid based on open circuit potential (OCP) measurements and electrochemical impedance spectroscopy (EIS). Titania made the surface of PCL roughest, which in combination with its high porosity explained why it was the most conducive to the growth of human fibroblasts, alongside being most prone to degradation in wet, corrosive environments and having the highest Poisson's ratio. Graphene, in contrast, made the surface of PCL smoothest and the bulk structure most porous, but also most conductive, with the OCP of -37 mV. The OCP of PCL supplemented with carbonated hydroxyapatite had the highest OCP of -134 mV and also the highest mechanical moduli, including the longitudinal (781 MPa), the shear (106 MPa), the bulk (639 MPa), and the elastic (300 MPa). The only benefit of the deposition of multilayered PCL films supplemented with all four inorganic additives was to enable a relatively high resistance to degradation. This study demonstrates that the properties of thin PCL films could be effectively optimized through the simple choice of appropriate inorganic additives dispersed in them. There is no single additive that proves ideal for improving all the properties of interest in PCL thin films, but their choice should be adjusted to the actual application. One such method of compositional optimization could prove crucial in the effort to develop biocomposites for superior performance in tissue engineering applications.

Seroprevalence of amoebiasis in Najran Saudi Arabia.

Amoebiasis is still the cause of one of the major health problem and a common lifethreatening parasitic disease affecting 12% of the world population. The present study was undertaken to evaluate the seroepidemiology of amoebiasis in Najran City, Saudi Arabia. A total of 455 blood samples taken from healthy persons and surplus serum from various hospitals serology laboratories, over a one year period, between September 2014 to September 2015 were screened for the presence of amoebic antibody in their blood serum using indirect hemagglutination assay (IHA). Out of the 455 samples of sera tested, 158 (40.7%) were found to be positive with a titers ranging from 1:32 to 1:512. The younger age groups had the highest t positive rates than the other groups (p<0.0001). The prevalence of infection was more common in females (57.3%) than males (29.8%), and showed statistical significance (P<0.001). There was a significant association on the presence of Amoeba antibodies in relation to the nationality of residence, and the seasonal dynamics of infection (P<0.05). The present study noticed that stray cats are potential reservoirs of infections and should be considered important to public health. The present findings highlighted that Entamoeba histolytica parasite is prevalent in Najran area. The establishment of such data will be beneficial for the public health authorities in the planning and implementation of specific prevention and control strategies of this infection in Saudi Arabia.