Background:The demand for esthetic orthodontic appliances is increasing so that the esthetic orthodontic archwires were introduced. This in vitro study was designed to evaluate the surface roughness offiber-reinforced polymer composite (FRPC) archwires compared to coated nickel-titanium (NiTi) archwires immersed in artificial saliva. Materials and Methods:Three types of esthetic orthodontic archwires were used: FRPC (Dentaurum), Teflon coated NiTi (Dentaurum) and epoxy coated NiTi (Orthotechnology). They were round (0.018 inch) in cross section and cut into pieces of 15 mm in length.Forty pieces from each type were divided into four groups; one group was left at a dry condition and the other three groups were immersed in artificial saliva (pH=6.75 ± 0.015) at 37ºC for 1, 14 and 28 days intervals. The AFM was used to evaluatesurface analysis of all samples.ANOVA, Kruskal-Wallis, LSD and Mann-Whitney U tests were used to identify and localize the source of differences among the groups. Results:At each immersion period, FRPC wires exhibited the highest Ra among the study groups, except at 28 days immersion period where the Teflon coatings were the roughest. On the other hand, the least rough surfaces were the epoxy coatings when compared to analogous esthetic archwires, except at 1 day immersion period where the Teflon coatings had the least roughness. However, statistically non-significant differences were found between Teflon and epoxy at the dry condition and the 1 day immersion. Conclusions:The epoxy coated archwires are the best and the most appropriate esthetic orthodontic alignment archwires in term of the least surface roughness initially and over the course of study period.
This study was conducted to determine the effect of different concentrations of ethanol extract of propolis against two fungi Botrytis cinerea, Altrnaria sp. The most important chemical constituents of propolis diagnosed by the Infra Red Spectroscopy, were the Flavonoids specificaly. Results showed a high antifungal activity of ethanol extract of propolis, evidently with a high concentration of extract (5) mg\ml, which completely inhibited the radial growth on both solid and liquid media (PDA &PD Broth ) of both fungi . We observed that , ethanol extract p
... Show MoreBackground: Health education was put as one of the components of primary health care elements and was recognized as a fundamental tool to the attainment of health for all
Objective: To evaluate the Knowledge, attitude regarding health education & to find out if there is any association between the gathered data and certain variables (age, gender, educational level, occupation). Methods: A Cross-sectional study done at Al Mustansyryia Primary Health Care Center from the 1st of January to 1st of May 2016. All patients attending the Primary Health Care Centers who were above 18 years of age and willing to participate in the research (303) were included in t
... Show MoreThe aim of this work is to shed light on the importance of medicinal plants, especially those that have extracts that have a direct effect on human health. The study and identification of botany is necessary because human life has become closely linked to the life of plants as food. In addition to using plants as food, primitive man did not stop at this point, but rather developed their use to hunt prey and also used toxic plant materials in wars. With the passage of time, the ancient man was able to link the wild plants that cover the surface of the earth and the diseases that afflict him, so he used these plants or Parts of it are for treatment. A medicinal plant is defined as one or more of its parts that contain one or more chemicals in
... Show MoreABSTRACT:
Microencapsulation is used to modify and retard drug release as well as to overcome the unpleasant effect
(gastrointestinal disturbances) which are associated with repeated and overdose of ibuprofen per day.
So that, a newly developed method of microencapsulation was utilized (a modified organic method) through a
modification of aqueous colloidal polymer dispersion method using ethylcellulose and sodium alginate coating materials to
prepare a sustained release ibuprofen microcapsules.
The effect of core : wall ratio on the percent yield and encapsulation efficiency of prepared microcapsules was low, whereas
, the release of drug from prepared microcapsules was affected by core: wall ratio ,proportion of coa
Аннотация
в статье рассматриваются проблемы преподавания русской литературы в иракской аудитории.. Использование литературы в преподавании иностранного языка, как правило, имеет две цели. Первая-чисто лингвистическая .. Вторая цель, однако, ассоциируется больше с экстралингвистикой и представляет собой ознакомление студентов с различными аспектами русской жизни, культуры,
... Show MoreNinety five samples were collected from different samples (urine, ear and wounds swaps), from hospitals in Baghdad city. The results of cultural, microscopic , biochemical tests indicated that in urine samples E.coli have high occurrence frequency 19 (47.5%) followed by Proteus mirabilis 18(45%) and Klebsiella species 1 (2.5%), while in wounds samples each of Pseudomonas spp. and Proteus mirabilis 10 (25%) , then followed by E.coli with 5 (12.5%) and Klebsiella species 3 (7.5%). Ear swaps samples revealed that Pseudomonas aeruginosa 7 (46%) was the major bacterium followed by Proteus mirabilis 4(26.6).Sensitivity test against eleven antimicrobial agents was done for all of the Proteus mirabilis isolates (32 isolates). The results display
... Show MoreSpectral and linear optical properties for a mixture of Rhodamine B (RB) and Fluorescein Sodium (Na Fl) organic laser dyes were determined at different concentrations 10-3, 10-4 M in ethanol solvent at room temperature. The intensity of absorption range is towards longer wavelengths (red shift). The quantum efficiency diminished while the radiative and fluorescence life time increased when increment concentration, organic laser dyes have a spectrum within the range 540-500 nm. Results demonstrate that a mixture of laser dyes are effective optical materials when contrasted with individual laser dyes. It can be utilized as resonator in cavity lasers.
In this paper we used Hosoya polynomial ofgroupgraphs Z1,...,Z26 after representing each group as graph and using Dihedral group to"encrypt the plain texts with the immersion property which provided Hosoya polynomial to immerse the cipher text in another"cipher text to become very"difficult to solve.
Sewer sediment deposition is an important aspect as it relates to several operational and environmental problems. It concerns municipalities as it affects the sewer system and contributes to sewer failure which has a catastrophic effect if happened in trunks or interceptors. Sewer rehabilitation is a costly process and complex in terms of choosing the method of rehabilitation and individual sewers to be rehabilitated. For such a complex process, inspection techniques assist in the decision-making process; though, it may add to the total expenditure of the project as it requires special tools and trained personnel. For developing countries, Inspection could prohibit the rehabilitation proceeds. In this study, the researchers propos
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