Background The application of nanotechnology to biomedical surfaces is explained by the ability of cells to interact with nanometric features. The aim of this study was to consider the role of nanoscale topographic modification of CPTi dental implant using chemical etching method for the purpose of improving osseointegration. Materials and methods: Commercial pure titanium rod was machined into 20 dental implants. Each implant was machined in diameter about 3mm, length of 8mm (5mm was threaded part and 3mm was flat part). Implants were prepared and divided into 2 groups according to the types of surface modification method used: 1st group (10 implant) remained without nano surface modification (control), 2nd group include (10 implant) etched with 15N H2SO4 and 30% H2O2, Surfaces were characterized by scanning electron microscope (SEM), Xray diffraction (XRD), atomic force microscope (AFM), thickness measurement for the invitro experiments. While for invivo part tibia of 5 white new Zealand rabbits were chosen as implantation sites. The tibia of each rabbit received two screws. Biomechanical test was performed to understand the bone-implant interface, after two weeks healing periods. Implants from 4animals were tested for the torque required to remove the implant from the bone and the other one animal was prepared for histological examination. Results and Conclusion: For in vitro results, scanning electron microscope showed that the chemical etching of Ti substrate becomes highly porous and has surface consisting of nanosized pits. Removal torque means value after 2 weeks of implantation mentioned that, there was a gradual increase in the removal torque mean values as a follow (M±SD): 12.625(N.cm) ± 0.517, 30.500(N.cm) ± 4.071for machined surface(X), nano chemically etched (X1) respectively. In addition, the histological analysis showed improved quality of bone in response to the nano modified screws, that the chemically treated implants shows trabeculated thread.
The results of the current study showed that the thyroid gland in an adult domestic cat (Felis catus) is located in the neck area on both sides of the trachea at rings 1–5. The gland consists of two lobes (right and left), and it is surrounded by a capsule of connective tissue consisting of two outer and inner layers, and a layer of fatty tissue overlaps with the outer layer of the capsule. In addition, the results of this study found that the histological structure of the thyroid gland is composed of several follicles that appear in different sizes and shapes. The follicles are lined with simple cuboidal epithelial tissue and sometimes appear lined with high and low simple cuboidal epithelial tissue. The gland is histologically c
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This study aimed to show the histological changes that 0ccured in Culex pipiens pipiens larvae and adults infected with Beauveria bassiana . The 4th instar larvae and adult mosquitoes were infected with B.bassiana in 10-4 spore/ml dilution, after 96 hours histological section was studied showing that the fungi infected all the body parts specially Cuticle , Epiderms, fat bodies and midgut. After 120 hours of exposure to the fungi the insect have a white appearance and covered with a thick coat of hyphea. Thus study shows biological control of B .bassiana on mosquitoes.
The results of the current study showed that the thyroid gland in an adult domestic cat (Felis catus) is located in the neck area on both sides of the trachea at rings 1–5. The gland consists of two lobes (right and left), and it is surrounded by a capsule of connective tissue consisting of two outer and inner layers, and a layer of fatty tissue overlaps with the outer layer of the capsule. In addition, the results of this study found that the histological structure of the thyroid gland is composed of several follicles that appear in different sizes and shapes. The follicles are lined with simple cuboidal epithelial tissue and sometimes appear lined with high and low simple cuboidal epithelial tissue. The gland is histological
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The aim of this article is to solve the Volterra-Fredholm integro-differential equations of fractional order numerically by using the shifted Jacobi polynomial collocation method. The Jacobi polynomial and collocation method properties are presented. This technique is used to convert the problem into the solution of linear algebraic equations. The fractional derivatives are considered in the Caputo sense. Numerical examples are given to show the accuracy and reliability of the proposed technique.
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The main objectives of this study were investigating the effects of the maximum size of coarse Attapulgite aggregate and micro steel fiber content on fresh and some mechanical properties of steel fibers reinforced lightweight self-compacting concrete (SFLWSCC). Two series of mixes were used depending on maximum aggregate size (12.5 and 19) mm, for each series three different steel fibers content were used (0.5 %, 1%, and 1.5%). To evaluate the fresh properties, tests of slump flow, T500 mm, V funnel time, and J ring were carried out. Tests of compressive strength, splitting tensile strength, flexural tensile strength, and calculated equilibrium density were done to evaluate mechanical properties. For reference mixes, the
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The wear behavior of alumina particulate reinforced A332 aluminium alloy composites produced by a stir casting process technique were investigated. A pin-on-disc type apparatus was employed for determining the sliding wear rate in composite samples at different grain size (1 µm, 12µm, 50 nm) and different weight percentage (0.05-0.1-0.5-1) wt% of alumina respectively. Mechanical properties characterization which strongly depends on microstructure properties of reinforcement revealed that the presence of ( nano , micro) alumina particulates lead to simultaneous increase in hardness, ultimate tensile stress (UTS), wear resistances. The results revealed that UTS, Hardness, Wear resistances increases with the increase in the percentage of
... Show MorePolyacrylamide Solutions of different concentrations (0.2, 0.4, 0.6, 0.8, 1.0 %) of Ag nanoparticles and ZnO nanoparticles were prepared, the viscosities and surface tension were measured for all solutions, where measurements indicated an increase in these properties with increased concentration, where the relative viscosity of polyacrylamide/zinc nanoparticles increased from 1.275 to 2.243, and the relative viscosity of polyacrylamide/silver nanoparticles increased from 1.178 to 1.934. Viscosity is significant parameters during electrospinning process. While the surface tension of the polyacrylamide/zinc nanoparticles has changed from 0.0343 Nm-1 to .0.0.0 Nm-1 and changed from .0.000Nm-1 to.0.0.0 Nm-1. Also the constants KH and KK were
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Background: Separation and deboning of artificial teeth from denture bases present a major clinical and labortory problem which affect both the patient and the dentist. The optimal bond strength of artificial teeth with denture base reinforced with nanofillers and flexible denture bases and the effect of thermo cycling should be evaluated. This study was conducted to evaluate and compare the shear bond strength of artificial teeth (acrylic and porcelain) with denture bases reinforced by 5% Zirconium oxide nanofillers and flexible bases under the effect of different surface treatments and thermo cycling and comparing the results with conventional water bath cured denture bases. Material and methods: Two types of artificial teeth; acrylic and
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