Background: To investigate the effect of different types of storage media on enamel surface microstructure of avulsed teeth by using atomic force microscope.Materials and methods : Twelve teeth blocks from freshly extracted premolars for orthodontic treatment were selected . The study samples were divided into three groups according to type of storage media :A-egg white , B- probiotic yogurt , and C-bovine milk . All the samples were examined for changes in surface roughness and surface granularity distribution using atomic force microscope, at two periods: baseline, and after 8 hours of immersing in the three types of storage media. Results: Milk group had showed a significant increase in the mean of the roughness values at the test period, while the egg white and the probiotic yogurt groups showed decrease in the surface roughness at the test period. No significant changes was found in the grain size of enamel surface of the avulsed tooth in any types of three storage media at eight hours interval. The use of egg white and probiotic yogurt to store the samples may be beneficial in that they contain various ions and proteins that fill up enamel valleys, while the longer periods of milk exposure encourage the bacteria to continue fermenting lactose, resulting in continual acid generation and increased demineralization. Conclusion : Milk group demonstrated the highest roughness values, while the egg white group demonstrated the lowest roughness values of the teeth. No significant changes in the grain size of enamel surface of the tested teeth in any types of three storage media at eight hours interval .
Al comentar un texto literario no se llega solamente mediante el estudio de su Historia. Ese estudio sería vano, se convertiría en una simple memorización de datos, creo yo.
Comentar un texto supone comprobar las características generales de un movimiento, estilo de un autor... en otras palabras comprender con profundidad el texto literario en s
This work presents a completely new develop an analyzer, named NAG-5SX1-1D-SSP, that is simple, accurate, reproducible, and affordable for the determination of cefotaxime sodium (CFS) in both pure and pharmaceutical drugs. The analyzer was designed according to flow injection analysis, and conducted to turbidimetric measurements. Ammonium cerium nitrate was utilized as a precipitating agent. After optimizing the conditions, the analysis system exhibited a linear range of 0.008-27 mmol. L-1 (n=29), with a limit of detection of 439.3 ng/sample, a limit of quantification of 0.4805 mg/sample, and a correlation coefficient of 0.9988. The repeatability of the responses was assessed by performing six successive injections of CFS at concentra
... Show MoreThe present study aimed to use the magnetic field and nanotechnology in the field of water purification, which slots offering high efficiency to the possibility of removing biological contaminants such as viruses and bacteria rather than the use of chemical and physical transactions such as chlorine and bromine, and ultraviolet light and boiling and sedimentation and distillation, ozone and others that have a direct negative impact on human safety and the environment. Where they were investigating the presence in water samples under study Coli phages using Single agar layer method and then treated samples positive for phages to three types of magnetic field fixed as follows (North Pole - South Pole - Bipolar) and compare the re
... Show MoreIn this work, the precursor [2-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylimino)acetic acid] was synthesised from 4-aminoantipyrine and glyoxylic acid, this precursor has been used in the synthesis of new multidentate ligand [2-((E)-3-(2-hydroxyphenylimino)-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylimino)acetic acid][H2L] type (N2O2). The ligand was refluxed in ethanol with metal ions [VO(II), Mn(II), Co(II) and Ni(II)] salts to give complexes of general molecular formula:[M(H2L)2(X)(Y)].B, where: M=VO(II), X=0, Y=OSO3-2, B=2H2O; M=Mn(II),Co(II) ,X=Cl, Y=Cl, B=0; M=Ni(II), X=H2O, Y=Cl, B=Cl. These complexes were characterised by atomic absorpition(A.A), F.T-I.R., (U.V-Vis)spectroscopies (1H,13C NMR for ligand only), alon
... Show MoreDie Zusammenfassung :
In der Forschung „ Die Wirkungen der Nachkriegliteratur „ findet man einen Überblick über die Wirkungen der Literatur im Allgemeinen und besonders über die Wirkungen der Nachkriegliteratur in Deutschland. Das Kurzgeschichte „ das Brot“ von Wolfgang Borchert „ wird in dieser Forschung als Beispiel analysiuert, weil sie die Nachteile des Kriegs und ihre Wirkungen auf die Familienbeziehungen behandelt. Die Hauptfiguren der Kurzgeschichte sind ein alter Mann und seine Frau. Der Schriftsteller bestimmt die Rolle der Frauen in Deutschland. Die Frau in dieser Geschichte ist stärker als ihren Mann , denn er war lügner und schwach.
Post-war Literature has an e
... Show MoreThis research seeks to try to address one of the important issues in society that prevents the state from achieving its social, economic, political and financial goals, represented by the low tax proceeds, through which it can achieve those goals. What is reflected on the tax proceeds, knowing that the General Tax Authority does not take into account the issue of analyzing the opportunity cost of corporate capital as one of the profit indicators when setting the annual controls, which leads to a decrease in the tax proceeds, and therefore the research objective will be to shed light on the importance of adopting the concept of analysis The opportunity cost by the General Tax Authority to achieve a tax proceeds commensurate with t
... Show MoreThe study seeks the relationship between the mathematical-procedural Knowledge and the logical-mathematical intelligence among students at the third stage in mathematics department. To this end, three questions were arisen: what is the level of mathematical-procedural Knowledge among the third stage students in mathematics department regarding their gender? Do male or female students have more logical-mathematical intelligence and are there significant differences base on their gender? What kind of correlation is between the level of mathematical-procedural Knowledge and the logical-mathematical intelligence of male and female students in the third stage in the mathematics department? A sample of (75) male and female students at the thir
... Show MoreThe consensus algorithm is the core mechanism of blockchain and is used to ensure data consistency among blockchain nodes. The PBFT consensus algorithm is widely used in alliance chains because it is resistant to Byzantine errors. However, the present PBFT (Practical Byzantine Fault Tolerance) still has issues with master node selection that is random and complicated communication. The IBFT consensus technique, which is enhanced, is proposed in this study and is based on node trust value and BLS (Boneh-Lynn-Shacham) aggregate signature. In IBFT, multi-level indicators are used to calculate the trust value of each node, and some nodes are selected to take part in network consensus as a result of this calculation. The master node is chosen
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