Commercially pure titanium (cpTi) is widely used as dental implant material although it was found that titanium exhibited high modulus of elasticity and the lower corrosion tendency in oral environment. Niobium(Nb) was chosen for this study as an alternative to cpTi implant material due to its bioinert behavior and good elastic modulus and moderate cost in addition to corrosion resistance. This study was done to evaluate the effect of biomimetic coating on the surface properties of the commercially pure titanium and niobium implants by in vitro and in vivo experiments. The in vitro study was involved etching the samples of each material in HCl then soaking in 10M NaOH aqueous solution. These samples were then immersed in a 5 times concentrated simulated body fluid for 14 days. Scanning Electron Microscope, Energy Dispersive X-ray, and X-Ray Diffraction tests were done to analyze surface changes. The in vivo study was done by the implantation of screw-shaped implants (two from each material, uncoated and the other was biomimetically coated) in the tibias of New Zealand rabbits. After 2 and 4 weeks of healing period, 20 rabbits were sacrificed for each period. A removal torque was done for ten animals in each group, whereas the other ten were used for histological testing and histomorphometric analysis with optical microscope.The in vitro experiments showed that the use of 14 days immersion in a concentrated simulated body fluid produced a layer of calcium phosphate on metal surfaces. The removal torque values and new bone formation were increased significantly in Nb than Ti, in coated than uncoated screws, and in 4 weeks than 2 weeks healing periods. The Nb implants had better biomechanical and biological properties than the commercially pure titanium implants and can be used as an alternative dental implant.
The weak and strong forms are so called because it is not their lexical content that primary matter, but the role they have in the sentence. The problematic confusion, our students encounter, in recognizing and producing the correct pronunciation of weak and strong forms of the English function words is the main incentive behind conducting this study. In order to gather the data, this paper used two types of tests: a recognition test and a production test. The general results reached through the analysis of the students' answers seem to conform to the researcher's assumption: students face a critical problem in recognizing and producing correct pronunciation of the weak and strong forms of the English funct
... Show Moreيعد القلق من الكتابة مؤشرا هاما قد يعيق القدرات الكتابية ويؤدي إلى عدم كفاءة الأداء. تهدف هذه الدراسة إلى تقييم القلق الكتابي لدى طلاب السنة الرابعة في كلية التربية البدنية وعلوم الرياضة العراقيين دارسي اللغة الإنجليزية كلغة ثانية (ESL) , حيث واجهوا صعوبات وعقبات في هذا المجال. ان تصميم الدراسة الحالية هو تصميم وصفي واداة القياس لهذه الدراسة تتالف من مقياس مكون من (20) فقرة. ان عينة الدراسة الحالية مختارة
... Show MoreThis paper describes the synthesis of ?- Fe2O3 nanoparticles by sol-gel route using carboxylic acid(2-hydroxy benzoic acid) as gelatin media and its photo activity for degradation of cibacron red dye . Hematite samples are synthesized at different temperatures: 400, 500, 600, 700, 800 and 900 ?C at 700 ?C the ?-Fe2O3 nanoparticles are formed with particle size 71.93 nm. The nanoparticles are characterized by XRD , SEM, AFM and FTIR . The 0.046 g /l of the catalyst sample shows high photo activity at 3x10-5M dye concentration in acidic medium at pH 3.
The importance of economic and technical feasibility studies include all of the investor, the society, the banks, the project and the government. As it will assist in achieving the optimal use of the available economic incomes on the national level and arranging the projects in priority which participates in achieving the government benefit without wasting the amounts .This is the research goal So, the research covered its theoretical aspect, of SAIs and the economic and technical feasibility studies then the role of the auditors in auditing those studies Then a mechanism was proposed includes a guidebook that provides guidelines for organizing the process of preparing and auditi
... Show MoreThis paper includes the synthesis of some new nucleoside analogues starting with 2-substituted benzimidazole derivative (7-9), that synthesized by condensation of O-phenylenediamine with p-chloro benzaldehyde and two substituted benzoic acid , which on nucleophilic substitution with propargyl bromide gave a new N-substituted compounds (10-12). D-Fructose and D-galactose were chosen as a sugar moiety which were protected, brominated and azotated to give azido sugars (5) and (6), then they were subjected to 1,3-dipolar cycloaddition reaction with N-substuted compounds afforded bloked nucleoside analoges (13-16), which after hydrolysis gave our target the free nucleoside analogues (17-20). All prepared compounds were identified by FT-IR
... Show MoreA new series of 5-methoxy-2-mercapto benzimidazole derivatives were synthesized by the reaction of 5-methoxy- 2-mercaptobenzimidazole with chloroacetic acid and affords 2-((5-methoxy-1H-benzo[d]imidazol-2-yl)thio) acetic acid (1),which on cyclization with acetic anhydride and pyridine gives 7- methoxybenzo[4,5]imidazo[2,1-b]thiazol- 3(2H)-one(2), which on condensation with different aryl aldehydes in the presence of anhydrous sodium acetate in glacial acetic acid, furnishes a arylidene thiazolidinone. The purity of the synthesized compounds was confirmed by melting point and TLC.The structures were established by different spectral analysis such as FTIR,1HNMR, and CHN analysis. The newly synthesized compounds (3a-d) were in vivo evaluated f
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