Background: 37% phosphoric acid (PA) is the traditional enamel etching technique prior to bracket adhesion, yet it has been implicated in numerous enamel injuries. The purpose of the current study was to create a calcium phosphate (CaP) etching paste in a simplified capsule formula that can underpin clinically adequate bracket bond strength without jeopardizing the integrity of enamel upon the debracketing procedure. Materials and Methods: micro-sized hydroxyapatite (HA) powder was mixed with 40% PA solution to prepare experimental acidic CaP paste. Sixty human premolars were assigned into two groups of 30 each. Enamel conditioning was accomplished using 37% PA-gel for control group and CaP paste for experimental group. Each group was further divided into two subgroups regarding the water storage (WS) period (24 h and 30 days). Shear bond strength (SBS) test conducted with examination of debonded surfaces for adhesive remnants and enamel damage using a digital microscope. Results: CaP paste produced significantly lower SBS values than PA (p < 0.01), yet sufficient for clinical use. PA etching caused often cracked enamel surfaces with excessive retention of adhesive remnants (mainly ARI scores 2 and 3). Contrarily, enamel treated with the experimental CaP paste exhibited smooth, unblemished surfaces mostly clean of adhesives residues (scores 0 and 1). Conclusion: a newly developed CaP paste in a capsule formula fosters clinically adequate bracket adhesion with a sustained bonding performance, allows a harmless bracket removal with minimal or no adhesive residues on debonded surfaces; thus, it can be introduced as a suitable alternative to PA.
The minimum approaches distance of probing electrons in scanning electron microscope has investigated in accordance to mirror effect phenomenon. The analytical expression for such distance is decomposed using the binomial expansion. With aid of resulted expansion, the distribution of trapped electrons within the sample surface has explored. Results have shown that trapped electron distributes with various forms rather an individual one. The domination of any shape is mainly depend on the minimum approaches distance of probing electrons
The traffic congestion caused by the increase in the number of vehicles in the cities as a result of the increase in the population and the density of construction requires the provision of appropriate infrastructure and the provision of transport systems and logistics services that meet the needs of the population to meet the many challenges now and in the future by introducing various modes of transport , In accordance with integrated plans such as the use of (pedestrian friendly environments, bicycles and their own paths, light rail, metro, express bus, as well as public transport buses and others), through the development of Projects High-level roads, such as the annual and major roads, etc., and integrated with the urban planning of
... Show MoreThe study of cooperative education is important not only for researchers but also for those interested in studying educational methods, such as university professors, teachers in schools, and all educational institutions. This is because of its effectiveness in teaching students, developing their skills, developing their ideas and employing them in the study and finding appropriate solutions to the questions posed by the teacher. It also helps in instilling a spirit of cooperation among the students by dividing them into groups to achieve the desired goals. The aim of the study is to clarify how important it is for teachers to use cooperative education in addressing the educational, social and psychological aspects when teaching stu
... Show MoreThis research laid the recruitment & use of IT Animatic digital TV drama & inviting ways of working is simple &effective in the level of producing images especially in TV drama, so the entry of this technology has created the concepts of new technology, and simple & effective at the same time with high level of modernity & technical innovation, this research deals with three chapters that includes two topics the animatic modes & the stages of production , & what is the atheistic aspects that is provided by this technology with the researcher reviewing the use of some TV dramatic Production series that was mentioned through this research.Which afterwards the researcher has analyzed a sample that was selected fo
... Show MoreForty-eight aborted women (Iraqi Arab Muslims) at the first trimester with a serological evidence of toxoplasmosis were investigated. Two age- and ethnic-matched control groups were included: 40 aborted women due to accidental events (Control I), and 40 unmarried (virgin) women (Control II). The subjects were evaluated for the following parameters: HLA-class I antigens (A, B and Cw), blood groups, total and differential counts of leukocytes, lymphocyte subpopulations (CD3+, CD4+ and CD20+ cells), phagocytosis of heat-killed yeast (phagocytic index and NBT index), and total serum levels of immunoglobulins (IgA, IgG and IgM) and complement components (C3 and C4). The HLA-A2 and -Cw8 antigens were significantly increased in the patien
... Show MoreSome new heterocyclic compounds containing, cyclohexenone, indazole, isoxazoline, pyrmidine and pyrazoline ring system were prepared from chalcones (1a,b). The starting chalcones (1a,b) were obtained by a base catalyzed condensation of appropriately substituted benzaldehydes and 2-acetylbenzofuran. The reaction of the prepared chalcones with ethylacetoacetate/hydrazine hydrate, hydroxylamine hydrochloride, urea, thiourea, hydrazine hydrate, phenyl hydrazine or hydrazide derivatives gave the mentioned heterocycles. All synthesized compounds have been characterized by physical and spectral methods.
اشكالية خطاب الحداثة في الفكر السياسي الاسلامي المعاصر
Psychology is one of the sciences that consciously overlap in terms of mutual influence with art forms in general and cinematic arts in particular. The psychological effect can be extrapolated into the visual image through the characters and their actions, especially the adoption of psychoanalytic ideas and proposals that came by (Freud), The cinema benefited from the concepts of psychology and participated in the process of creativity and the manufacture of events or the actions of characters, such as the concepts of consciousness and subconsciousness to express the psychological dimension of the film events, these data can be counted on the level of nightmares in the cinematic movies.
The methodological framework included the rese