The limited availability of the two-circle diffractometer to collect intensity measurements down to the monoclinic system has been extended in a novel procedure to collect intensities for the triclinic system. The procedure involves the derivation of matrix elements from graphical representation of the reciprocal lattice. Offset of the origins of the upper layers from that of the zero-layer - characteristic of triclinic system - is determined and the 3 x 3 matrix elements are evaluated accordingly. Details of crystal alignment by X-rays for the triclinic system utilizing the intensities of equivalent reflections is described
Background: With the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.The present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (Hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). Materials and Methods: The samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). They were divided as the following: group I (control): the porcelain surface left u
... Show MoreNew Schiff base ligand (E)-6-(2-(4-(dimethylamino)benzylideneamino)-2-(4-hydroxyphenyl)acetamido)-3,3- dimethyl-7-oxo-4-thia-1- azabicyclo[3.2.0]heptane-2-carboxylic acid = (HL) was synthesized via condensation of Amoxicillin and 4(dimethylamino)benzaldehyde in methanol. Figure -1 Polydentate mixed ligand complexes were obtained from 1:1:2 molar ratio reactions with metal ions and HL, 2NA on reaction with MCl2 .nH2O salt yields complexes corresponding to the formulas [M(L)(NA)2Cl],where M=Fe(II),Co(II),Ni(II),Cu(II),and Zn(II), A=nicotinamide .
Background: The association between facial types and dental arches forms has considerable implications in orthodontic diagnosis and treatment planning. The aim was to establish the maxillary and mandibular dental arches width and length in skeletal and dental class II division 1 and class III malocclusion groups, find out the most frequent dental arch form and facial type and the association between them and to check the gender differences. Materials and Methods: Frontal and lateral facial photographs and maxillary and mandibular occlussal photographs for 90 iraqi subjects with age 18-25 years old (45 males and 45 females) divided equally into three groups, the 1st group with class II division 1malocclusion (overjet more than 3mm but less t
... Show MoreIn :the _pr sent _paper we report ths. ynthesis ·of a new li:ga!!d..
[f4LJ [{'2 {1-'[(2-hyd•:0xy-.ben:zy1i.den·e)..,bxcJrazanci}:etby-l }benzerieÂ
J,5 t;rtiol .aad its complexes ·w-ith '('Mlif(1 J Fev 1 ), ed(J'l), and. :f.::I:g 01>-)
The ligand \VS preP..ated rin tWo steps' • fp I t}Je nrst stea -soJutiQil Qf
-saUcyla[deeyeq. ip methatt:oJ . re3ctcd lU1der reflux
... Show MoreEight different Dichloro(bis{2-[1-(4-R-phenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})iron(II) compounds, 2–9, have been synthesised and characterised, where group R=CH3 (L2), OCH3 (L3), COOH (L4), F (L5), Cl (L6), CN (L7), H (L8) and CF3 (L9). The single crystal X-ray structure was determined for the L3 which was complemented with Density Functional Theory calculations for all complexes. The structure exhibits a distorted octahedral geometry, with the two triazole ligands coordinated to the iron centre positioned in the equatorial plane and the two chloro atoms in the axial positions. The values of the FeII/III redox couple, observed at ca. −0.3 V versus Fc/ Fc+ for complexes 2–9, varied over a very small potential range of 0.05 V.
... Show MoreThe eaction of 2 4 .6-trihydroxyactophenonemonohydra1e with
l hydr.azine monohydrate was realized ti·nder reflu.(( in methanol and i:l.
Jew drops of glacial acetic acid we.re added to give lhe'(int rmediate)
2-(1hydr pno-ctbyt)-benzcne-·1.3.5-r:Qql, which reacted wittl
saEcy.laldehyde. jn methm)ql to gjy;e 'a new :tyRe CNzOi) Ligand (H:flL]
f(2-{1-[(2-=bydroxy-bertzylide·ne)-bydrazqoo,J-e·thy.1}bcnze·neJ ;3·,5
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