Background: Dental implants act as infrastructure for fixed restoration to look like as a natural tooth. Osseointegration is a biological events and considered as a base for success of dental implant. The aim of this study is to evaluate the bond strength between bone and Ti implant coated with mixture of nano hydroxyapatite-chitosan-collagen compared with Ti implants coated with nano hydroxyapatite implanted in rabbit tibia, after different period of implantation time (two and six weeks) by torque removal test. Material and methods: 36 screws of commercially pure titanium; 8mm in length and 3mm diameter , 18 screws coated with mixture of nano hydroxyapatite-chitosan-collagen and18 screws coated with nano hydroxyapatite by dip coating. Structural characteristics was assessed by scanning electron microscope, and FTIR analysis. The screws were implanted in 18 healthy adult male New Zeeland rabbits each tibia received one screw, right tibia received screw coated with nano hydroxyapatite while left tibia received screw coated nano hydroxyapatite-chitosan-collagen composite. Removal torque test was done by torque meter to determine the highest torque value necessary to remove the implants from tibia bone after different period of time of implantation(2 and 6 weeks). Result: Nano hydroxyapatite-chitosan-collagen composite coating was resulting in higher torque removal value than nano hydroxyapatite coating for two periods of time. Conclusion: Concluded that addition of collagen and chitosan to nano hydroxyapatite was more efficient in rapid bone formation than nano hydroxyapatite only.
The dynamical behavior of a two-dimensional continuous time dynamical system describing by a prey predator model is investigated. By means of constructing suitable Lyapunov functional, sufficient condition is derived for the global asymptotic stability of the positive equilibrium of the system. The Hopf bifurcation analysis is carried out. The numerical simulations are used to study the effect of periodic forcing in two different parameters. The results of simulations show that the model under the effects of periodic forcing in two different parameters, with or without phase difference, could exhibit chaotic dynamics for realistic and biologically feasible parametric values.
The purpose of this study was to investigate the effect of omega-3 poly unsaturated fatty-acids co-administered with the therapeutic dose of lornoxicam on liver of healthy rats. Twenty-eight adults male rats weighing 180-200g were used in this study and the animals were randomly divided into four groups of seven rats each. Group I: negative control/rats intraperitoneally injected with normal saline in a dose 5ml/kg/day; Group II: rats intraperitoneally injected with lornoxicam at dose 0.7 mg/kg/day; Group III: rats orally-administered omega-3 only at a dose 185mg/kg/day; Group IV: rats co-administered omega-3 (185mg/kg/day) orally and in
... Show MoreGlobal warming and environmental damage have become major problems. The production of Portland cement releases large quantities of gas, which cause pollution to the atmosphere. This problem can be solved via the use of sustainable materials, such as glass powder. This study investigates the effect of partial replacement of cement with sustainable glass powder at various percentages (0, 15, 20, and 25%) by weight of cement on some mechanical properties (compressive strength, flexural strength, absorption, and dry density) of Reactive Powder Concrete (RPC) containing a percentage of Polypropylene fibers (PRPC) of 1% by weight. Furthermore, steam curing was performed for 5 hours at 90oC after hardening the sample directly. The RPC was
... Show MoreThe goal of the current study was to research the changes in hematological parameters: WBC count, RBCs count, Hb, PCV, neutrophil, lymphocyte, and monocyte in albino mice infected with Aspergillus fumigatus by intraperitoneal injection after induced immunosuppression by intraperitoneal injection of cortisone. The current research also examined an attempt to reduce the infection load by treating Solanum aculeastrum. The result shows higher decreased significance (P≤0. 05) in RBCs, Hb, and PCV after being infected with A. fumigatus 7. 1 ± 0. 8, 11. 3 ± 0. 5 and 41. 5 ± 2. 4, respectively, while the total WBC count, neutrophil, lymphocyte, and monocytes were increased significantly (P≤0. 05) after treatment with S. aculeastrum i
... Show MoreBackground: This study aims to investigate the effect of fixed orthodontic appliances and/or antihypertensive drugs on the weight of experimental rats. Materials and Methods: Thir-ty-six male Wistar albino rats were subjected to a split-mouth design study, in which an orthodontic appliance was inserted in one side to move the first molar mesially for 2 weeks while the other side acted as a control to tooth movement. The rats were allocated into three groups: group A (n = 12), without any pharmacological treatment; group B (n = 12), subcu-taneous injection of bisoprolol fumarate (5 mg/kg) daily; and group C (n = 12), subcutaneous injection of valsartan (10 mg/kg) daily. A fixed orthodontic appliance with a closing coil spring delivering 5
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The extremes effects in parameters readings which are BOD (Biological Oxygen Demands) and DO(Dissolved Oxygen) can caused error estimating of the model’s parameters which used to determine the ratio of de oxygenation and re oxygenation of the dissolved oxygen(DO),then that will caused launch big amounts of the sewage pollution water to the rivers and it’s turn is effect in negative form on the ecosystem life and the different types of the water wealth.
As result of what mention before this research came to employees Streeter-Phleps model parameters estimation which are (Kd,Kr) the de oxygenation and re oxygenation ratios on respect
... Show MoreThis work presents an experimental study of heat transfer and flow of distilled water and metal oxide nanofluid Fe3O4-distilled water at concentrations of (φ = 0.3, 0.6, 0.9 %) by volume in a horizontal pipe with constant magnetic field. All the tests are carried out with Reynolds number range (2900-9820) and uniform heat flux (11262-19562 W/m2). The results show that, the nanofluid concentration and magnetic intensity increase, the Nusselt number increases. The maximum enhancement in Nusselt number with magnetic nanofluid is (5.4 %, 26.4 %, 42.7 %) for volume concentration (0.3, 0.6, 0.9 %) respectively. The enhancement is maximized with magnetic intensity (0.1, 0.2, 0.3 tesla) respectively to (43.9, 44
... Show MoreThe numerical analysis was conducted to studying the influence of length to diameter ratio (L/D) on the behavior of the soil treated with sand columns treated with 8% sodium silicate for both floating and end bearing type by using finite element method (Plaxis 3D Foundation ) for isolated foundation of real dimensions. The analysis’s study indicate that in the floating type the best improvement ratio was achieved at (L/D=8) when using columns with a diameter of (0.5, 0.7), but when using columns with a diameter of 0.3 m, it was noticed that the bearing improvement ratio increases with increasing (L/d). While the results of the analysis for end bearing type show that the higher improvement ratio was achieved at (L/D=4) when using columns w
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