Background and Aim: Although orthodontists have long recognized that the extraction (Ext) of premolars often is accompanied by changes in the soft tissue profile, investigations indicate that the soft tissue does not always respond favorably to hard-tissue retraction. This study was designed to evaluate the effects of treatment, with and without premolar Ext, on the lateral facial profiles of borderline patients with particular reference to the curvature of the upper and lower lips.Materials & Methods: Eighty-nine border line patients were included in this study. 41 patients were treated with a non-extraction (Non-Ext) protocol, 16 patients were treated with extractions of 5.5, 18 patients with 4.4 and 14 patients with 4.5. All pre-and posttreatment lateral cephalograms were traced and analysis by one examiner. To quantify the soft tissue effects of growth and treatment, the depths of the upper and lower lip curves were calculated in two ways relative to the PM reference line and anterior soft tissue reference line.Results: The changes in depth of upper and lower lip curves were statistically significant (P<0.001).The Non-Ext group showed an increase in depth of upper and lower lip curves, whereas the Ext group showed a decrease in depth of upper and lower lip curves. No significant differences were found between the various extraction sequences (5.5, 4.4, 4.5) for depth of the upper and lower lip curves changes.Conclusions: l) The upper and lower lip changes were significant; more retrusive in the Ext group and more protrusive in the Non-Ext group. 2) There were no significant post treatment differences in the depths of upper and lower lip curves between premolar extraction sequences.

To investigate the electromagnetic interaction of molecules inside the nanotubes, first, the structure of nanotubes B16N16 was optimized with hybrid density functional theory (B3LYP) using the EPR-II basis set, then Cu, Cu+, Cu++were located in nanotube and we studied the total energy, band gap energy, electrical potential, changes of band gap energy in terms of total energy and dipole moment in the B16N16-X (X=Cu, Cu+, Cu++) systems. Also, to investigate the electromagnetic interaction of molecules inside the nanotubes, we studied the nuclear magnetic resonance properties (NMR) and shielding parameters between nanotubes.

Background & Aim: extraction of first premolars and their influence on the third molars' eruption and impaction has been of concern to dental profession. The aim of this study, was to determine the relation between the changes of third molar angulation and the first premolar extraction in orthodontic treatment.Materials and Methods: This analytical study was carried out on total 90 subjects selected from two orthodontic clinics. Forty five subjects (14 males and 31 females) 14.46±1.64 years old treated with extraction of four first premolars (extraction group) and the other 45 subjects (13 males, 32 females) 13.9±1.99 years old treated by nonextraction were studied. Lateral cephalometric and panoramic films were studied before and after treatment. Eight angles in panoramic, four angles and 4 linear variables on the lateral cephalometric films were measured. Age, gender, amount of crowding in both dental arches and treatment duration were matched in the two groups. Student t and chi square tests were used to analyze the data.Results: The upper eruption space and the lower eruption spaces were more in extraction group and the difference was significant (P=0.02, P=0.004, P<0.001). The changes of third molar angulation were not significant between the two groups. Eruption rate of the third molars in both arches were more in extraction group and the difference was significant (P<0.001).Conclusion: extraction of the first premolars did not influence the changes in the third molar angulation, while it affected the third molar eruption by space creation. It seems that extraction of the first premolars is not a way for secure eruption of the third molar.

in this study, Ni-Cu/Cu multilayers from a single sulfate/sulfamate bath using electrodeposition method from two solutions; ultrapure solution (without impurity of Co) and impure solution (with 0. 2% Co) in galvanostat/potentiostat (G/P) mode was prepared at optimized Cu deposition potential. Magnetoresistance (MR) measurements were performed at room temperature for the Ni-Cu/Cu multilayers as a function of (Cu) layer thickness for both ultrapure and impure electrolytes. The magnetoresistance curves represent an anisotropic magnetoresistance (AMR) for multilayered samples prepared by ultrapure electrolyte and giant magnetoresistance (GMR) by impure electrolyte, so that the maximum GMR value was obtained for Ni-Cu/Cu multilayer with 3. 0nm/4. 2nm thickness. The X-ray diffraction pattern (XRD) was used for structural analysis of multilayer films. The XRD pattern confirmed the presence of satellite peaks, indicating the existence of a superlattice structure. The nominal thickness of the multilayers (Λ nominal) was compared with the thickness of the X-ray diffraction pattern (Λ XRD), which was significantly consistent. . The morphology of the samples was performed using scanning electron microscopy (SEM) which implies uniformity of deposition during the layering process. The results showed that with decreasing thickness of nonmagnetic layer (Cu) the coercivity decreased and saturation magnetization increased.

In this research Co-Cu/Cu and Fe-Co-Cu/Cu multilayer were electrodeposited on sputtered gold on glass substrates. The kinetic roughening of samples was investigated by atomic force microscopy (AFM) images and the logarithmic scale plots of roughness as a function of scan lengths. The XRD patterns indicate the multilayer thin films follow their substrate textures. The EDX results show that in both Co-Cu/Cu and Fe-Co-Cu/Cu multilayers the Co content increases as the magnetic layer thickness increasing. The SEM images show that increasing the magnetic and nonmagnetic layers thicknesses leads to increase the grain size of multilayers. The Magnetic property studies of samples reveal that the coercivity decreases and the remanence increases by presenting of Fe in magnetic multilayers.

The aim of this work was to develop a new and simple coacervative extraction method for the preconcentration and spectrophotometric determination of Cu(II) in water samples. Dithizone was used as the chelating agent while an anionic surfactant, namely sodium dodecyl sulfate (SDS), was used as extracting agent at room temperature. Central composite design (CCD) based on response surface methodology (RSM) was employed to optimize main experimental parameters such as pH values of solutions, concentration of the surfactant and volume of the saturated salt. Analytical characteristics of the method such as limit of detection, linear range, relative standard deviation (R. S. D. ) and relative standard error (R. S. E. ) were calculated under the optimum conditions. The calibration graph was linear in the range of 10-100 ng ml-1 with the detection limit of 3. 8 ng ml-1. The interference effects of some anions and cations were also studied. The method was successfully applied for the determination of Cu(II) in water samples.

Introduction: Use of an adhesive with a suitable composite resin is an important factor in tooth-colored restorations and increasing marginal sealing ability. The aim of this study was to evaluate the microleakage of various adhesives with composite resins using fluid filtration and dye extraction techniques and assessment of the correlation between these two techniques.Materials and Methods: In this in vitro study, class II cavities were prepared on the proximal surfaces of 48 extracted sound human premolar teeth, measuring 1.5±0.5 mm in gingival width, 4 mm in occluso-gingival height and 1.3 of the inter-cuspal distance in width. The samples were divided into four groups (n=12). Group 1; OptiBond Solo Plus adhesive/Herculite XRV composite resin; Group 2: OptiBond Solo Plus adhesive/Master Dent composite resin; Group 3: Prime & Bond NT adhesive/Herculite XRV composite resin; Group 4: Prime & Bond NT adhesive/Master Dent composite resin. Microleakage was assessed primarily by fluid filtration and then by dye extraction techniques. Data were analyzed with Kruskal-Wallis and Mann-Whitney tests, with Bonferroni correction and Spearman's rho correlation test at 95% confidence interval.Results: The minimum and maximum mean microleakage values were recorded in fluid filtration and dye extraction techniques groups 1 and 4, respectively. There were significant differences between the experimental groups in microleakage with the two methods of leakage assessment (p value=0.001). Spearman's rho revealed a strongly direct correlation between the two methods (r=0.797, p value=0.000).Conclusion: In both methods of microleakage assessment, use of ethanol-based in comparison to acetone-based adhesive resulted in microleakage reduction. Application of light-cured composite resin contrary to self-cured composite resin with both types of adhesives increased marginal sealing ability.