The zirconia ceramic restoration (ZCR) is used as substitutes for the metal-ceramic restoration. Clinical studies demonstrating of ZCRs showed a high fracture incidence of veneering layer than metal-ceramic restorations. This attributed to the low bond strength of zirconia to veneering ceramic as a result of lacking of glass content in its matrix. Surface treatment was proposed to improve the bonding strength between zirconia and veneering ceramic. Several studies revealed that some treatment such as airborne particle abrasion (APA) is responsible for generating chipping of veneering ceramic. The study aimed to develop a new zirconia coatings to increase bonding strength between zirconia substrate and veneering porcelain. Three groups of 150 zirconia specimens (discs, rods and crowns) were divided according to the type of surface treatments; Group M1 designated unsintered zirconia specimens coated with a mixture of glaze porcelain powder and partially-sintered zirconia powder prepared at 1100 °C with two particle sizes; A (26 ± 0.3 μm) and size B (47 ± 0.5 μm), group M2 was coated with mixture of ceramic liner paste and same selected particle sizes of partially-sintered zirconia powders. The coated groups (M1 and M2) subdivided according to powder sizes into M1A, M1B, M2A and M2B. APA group (as control) of sintered zirconia specimens abraded with 50 μm aluminium oxide powder. Surface area roughness (Sa) was measured by surface texture analyser. Surface morphology and elemental composition were analysed by scanning electron microscope (SEM). Crystallographic phases were identified by X-ray diffraction (XRD). The coefficient of thermal expansion (CTE) was assessed by a thermomechanical analyser. For shear bond strength (SBS) test was evaluated by a universal testing machine (UTM). The fracture strength (FS) test prepared and measured by Cercon CAD/CAM system and UTM. Fractographic analysis for SBS and FS were examined by a stereomicroscope and SEM. For each test and measurement, 10 specimens were used per group. Finite element analysis (FEA) was used to simulate and predict the iv stress distributions of the static oblique load in coated and non-coated zirconia crown models. The collected data were analysed by one-way ANOVA and Tukey HSD test at (P<0.05). Surface roughness results showed significant differences among all groups (P<0.000). The M1B group exhibited a higher Sa value (10.33 ± 0.59 μm) among the tested groups. XRD analysis showed tetragonal and monoclinic phases in the control group while only tetragonal was detected in the coated groups. The SBS values for coated groups were higher than the control group. The M1B group showed higher and significant differences in SBS value (37.54 ± 4.38 MPa) among other tested groups (P<0.05). The FS test indicated that coated M1B group (647.92 ± 97.33 N) higher than the other groups (P<0.00). FEA showed the coated crown models have lower stress level than the non-coated model. The new coating (M1B) by airbrush spray technique considered as an alternative way to APA treatment to improve the bond strength of zirconia substrate to veneering ceramic and indicating as an applicable surface treatment for improving the clinical performance of the coated ZCR.
Thiamethoxam is a synthetic organic insecticide belong to The most significant new class of pesticides created in the last thirty years is neonicotinoids. This study's objective was to determine the effect of thiamethoxam, lambda cyhalothrin and their combination on biochemical parameters, the levels of free radicals and enzymes activities liver of male.Forty Rats ( 150-170 g ) were used. animals Were separated into four groups, each with ten rats.The Gp1 was used as control, the Gp2 was used to study the effect of thiamethoxam for 3weeks, the Gp3 was employed to examine the impact of lambda cyhalothrin for 3 weeks and the Gp4 was used to research the impact of thiamethoxam and lambda cyhalothrin for 3 weeks. thiamethoxam and/or lambda cyha
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This in order to test the effect of food on growth and fecundity, two kinds of food have been used the algae Scendesmus quadricaudae and fresh water shrimp powder. For two generations, growth and productivity have been followed up. The fresh water shrimp has been noticed as a food better than algae, because it caused recording, for the two generation higher length rate for the weeks of experiment. The individuals length rate at the end of the forth week reached 9.35 and 9.48 mm for the first generation and second generation respectively. The average length weekly increase rate for the first and second generations individuals feeding on dried shrimp was higher through the first and second week compared to what was recorded when feeding alga
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This study aimed to investigate the antibacterial effect of Cinnamomum verum ethanolic extract against Proteus mirabilisisolated from the oral cavities of humans and dogs. Fifty samples, collected from both humans and dogs, corresponding to isolates obtained using the primary and VITEK 2 systems, yielded eight isolates that were positive for P. mirabilis. Different doses of the Cinnamomum verum extract were evaluated against the isolated P. mirabilis cultures, ranging from 125 to 2000 micrograms. Significant results were observed starting from 500 micrograms, yielding a 19 mm zone of inhibition. These results corroborate the findings of the GC-MS test on the extract, confirming the antibacterial properties of the active compounds resulting
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Abstract: Stars whose initial masses are between (0.89 - 8.0) M☉ go through an Asymptotic Giant Branch (AGB) phase at the end of their life. Which have been evolved from the main sequence phase through Asymptotic Giant Branch (AGB). The calculations were done by adopted Synthetic Model showed the following results: 1- Mass loss on the AGB phase consists of two phases for period (P <500) days and for (P>500) days; 2- the mass loss rate exponentially increases with the pulsation periods; 3- The expansion velocity VAGB for our stars are calculated according to the three assumptions; 4- the terminal velocity depends on several factors likes metallicity and luminosity. The calculations indicated that a super wind phase (S.W) developed on the A
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Shatt al-Arab is the only navigational artery in Iraq, extending from the city of Qurna to its mouth in the Arabian Gulf at the city of Al-Fao within the governorate of Basrah for a length of approximately 204 km. Its width ranges from 400 m to 2000 m, and its depth ranges from 8 m to 20 m. The southern part of it, 93 km long from Umm al-Rassas Island to Ras al-Bisha, represents the international border between Iraq and Iran, where the Thalweg line represents the border between the two countries, which is the deepest point in the riverbed (according to the 1975 Algiers Agreement). The western bank (the Iraqi side) within the common border of Shatt al-Arab is subject to continuous erosion, which leads to the shifting of t
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The protective effect of ginger extract against cisplatin-induced hepatotoxicity and cardiotoxicity was evaluated in 30 albino white rats(weighing 200-300 gm ) classified into 5groups (6 rats per each group). The rats were treated with 0.5g/kg/day or 1g/kg/day ginger extract orally 5 successive days before and 5 successive days after induction of toxicity with intraperitoneal (IP) injection of (10mg/kg ) cisplatin, resulted in a significant reduction in the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) , total serum billirubin(TSB) , lactate dehydrogenase (LDH) and creatine kinase(CK) enzymes in comparison with the cisplatin treated animals; ginger extract
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Objectives: To find out the effect of l-hydroxyphenazine (1-HP) on viability of T-lymphocytes and the reflects of this
effect on experimental hyadatidosis on hydatid cyst protoscoleces infectivity in vivo.
Methodology: Four groups of white male /ه/mice were experimentally infected with four concentrations of (1-HP)
with challenge dose of 2000 protoscoleces /1 ml with negative (9.8.5) and positive (P.H.A) control groups.
Results: It has been found that the higher concentrations (75,100) 1101/111 of the (1-HP) causes significant
decrement in the lymphocytes viability in comparison with negative and positive control groups. (060.01).
Recommendations: The study recommended using concentrations lower than 25 pmole Iml which