Abstract: Objectives: To investigate the effect of temperature elevation on the bonding strength of resin cement to the zirconia ceramic using fractional CO2 laser. Background: Fractional CO2 laser is an effective surface treatment of zirconia ceramic, as it increases the bonding strength of zirconia to resin cement. Methods: Thirty sintered zirconia discs (10 mm diameter, 2 mm thickness) were prepared and divided to three groups (N=10) and five diffident pulse durations were used in each group (0.1, 0.5, 1, 5 and 10 ms). Group A was treated with 10 W power setting, group B with 20 W and group C with 30 W. During laser irradiation, temperature elevation measurement was recorded for each specimen. Luting cement was bonded to the treated zirconia surfaces and cured for 30 seconds. Shear bond strength was evaluated by a testing machine (universal) with bond failure mode determination. Results: The lowest temperature elevation measurement of the irradiated specimen which gave maximum shear bond strength was about 1.6±0.3 Ċ higher than ambient room temperature (27±0.2 ºC). Apparent micromechanical irregularities were seen in the treated samples and cracks formation with increased pulse duration and power setting were also observed. Conclusions: The temperature elevation is a vital factor in the surface roughness of zirconia ceramic with fractional CO2 laser irradiation and the lowest temperature elevation at best shear bond strength of zirconia ceramic to the resin cement is satisfied with the shorter pulse duration of 0.1 millisecond.
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Ursolic acid (UA, 3 ?-hydroxy-urs-12-en-28-oic acid) are isomeric triterpenic acids. The high quantities of pentacyclic triterpenoids in Scabiosa species seems to be obvious and there is an evidence that most of pentacyclic triterpenoids that have been isolated are saponins. This is one of the most important characteristic of the genus Scabiosa, the main aglycones are ursolic acid and oleanolic acid. In the current study, isolation from the aerial part and roots of Scabiosa palaestina L. was performed using Preparative HPLC. Furthermore, detection and quantitation of ursolic acid was performed by high performance thin layer chromatography (HPTLC). The identification of isolated triterpenoid involves two methods including FT-IR coupl
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Background: Chronic renal failure (CRF) is a clinical syndrome that occurs when there is gradual decline in renal operation overtime.
Objective: This study aims to investigate the prevalence of depression among medical students at university of Baghdad, college of medicine in Iraq and the association between some variables and depression.
Aim: This study aimed to identify the impact of tobacco use in the etiology of chronic renal failure among Sudanese patients in Omdurman Military Hospital and Omdurman Kidney Dialysis Center
Materials and methods: This descriptive community-based study was conducted in Khartoum State. A random sample of 100 cases with chronic renal failure and 100
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In this work, functionally graded materials were synthesized by centrifugal technique at different
volume fractions 0.5, 1, 1.5, and 2% Vf with a rotation speed of 1200 rpm and a constant rotation time, T
= 6 min . The mechanical properties were characterized to study the graded and non-graded nanocomposites
and the pure epoxy material. The mechanical tests showed that graded and non-graded added alumina
(Al2O3) nanoparticles enhanced the effect more than pure epoxy. The maximum difference in impact strength
occurred at (FGM), which was loaded from the rich side of the nano-alumina where the maximum value was
at 1% Vf by 133.33% of the sample epoxy side. The flexural strength and Young modulus of the fu
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Abstract
Most universities in the world are largely committed to creating credible and transparent admission standards that provide justice in admission and have the ability to predict students' performance in their chosen programs. Hence, this study aimed to reveal the predictive ability of the acceptance criteria for the level of performance of master's students in the College of Education at Sultan Qaboos University. Quantitative data were collected from (115) students' admission documents for those accepted in the postgraduate programs for the academic year 2019-2020, and GPA data was collected from students’ transcripts for the fall semester of 2019. Qualitative data were also collected from the interviews
... Show MoreAbstract The current study is a theoretical study that aims to underline the role of picture books as a serious genre of children's literature in raising children's understanding of English literature and life concepts; especially for non-English speakers. Unfortunately, most Iraqi people have developed a social phobia of learning English since childhood. This phobia is resulted from the heavy traditional reading and writing assignments as well as hard exams. Therefore, this study suggests incorporating more interesting literary material like picture books that would bring pleasure and help in raising children's love and cognition of English Language. More significantly, it calls to replace the old curriculum with a more vital one
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Abstract The current study is a theoretical study that aims to underline the role of picture books as a serious genre of children's literature in raising children's understanding of English literature and life concepts; especially for non-English speakers. Unfortunately, most Iraqi people have developed a social phobia of learning English since childhood. This phobia is resulted from the heavy traditional reading and writing assignments as well as hard exams. Therefore, this study suggests incorporating more interesting literary material like picture books that would bring pleasure and help in raising children's love and cognition of English Language. More significantly, it calls to replace the old curriculum with a more vital
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Introduction: Biocides are commonly used for disinfection in a variety of contexts. They are generally used to avoid infection by controlling biofilm on medical equipment. However, the literature lacks information on the effect of biocide on efflux pump gene expression. Objective: To determine the influence of biocide on biofilm development and efflux pump acrA and ramA gene expression. Methodology: The microtiter plate method was used to identify biofilm development in 80 isolates of K. pneumoniae. The minimal inhibitory concentrations (MIC) of three biocides (quaternary ammonium compound (QAC), chlorohexidine digluconate, and chloroxylenol) were estimated. The effect of QAC on the intensity and viability of biofilms was investigated as we
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