OBJECTIVE this study was aimed at characterizing the craniofacial structures, i.e. the facial skeleton, cranial base, dentition, pharyngeal airway space, and the hyoid bone position, in healthy preschool children without sleep-related breathing disorder. MATERIALS AND METHODS from lateral cephalometric radiographs taken of 92 children for diagnostic purposes, 45 were selected for the present ...

Base flipping is the movement of a DNA base from an intrahelical, base-stacked position to an extrahelical, solvent-exposed position. As there are favorable interactions for an intrahelical base, both hydrogen bonding and base stacking, base flipping is expected to be energetically prohibitive for an undamaged DNA duplex. For damaged DNA bases, however, the energetic cost of base flipping may b...

objective: the present study assessed the association of size, axial angulation, developmental stage and bud position of the mandibular third molar with the second molar impaction in patients with mandibular second molar impaction. methods: in this descriptive-analytical study (case-control design), dental records of 5,420 patients in the age range of 12-15 years who underwent orthodontic treat...

Shield metal arc welding on the high strength low alloy steels in pipelines to transport natural gas from Iran is of great importance. In this article the effects of annealing heat treatment on properties of multi pass welding in different situations (6-4:30 , 4:30-3 , 3-1:30 , 1:30-12) with 36 in outside diameter is evaluated by chemical,  metallography, tensile, toughness and hardness. Tensil...

Bacterial and archaeal topoisomerase I display selectivity for a cytosine base 4 nt upstream from the DNA cleavage site. Recently, the solved crystal structure of Escherichia coli topoisomerase I covalently linked to a single-stranded oligonucleotide revealed that R169 and R173 interact with the cytosine base at the -4 position via hydrogen bonds while the phenol ring of Y177 wedges between the...

The new synergic base [PMDETA.K(TMP)(Et)Zn(Et)] selectively zincates 4-(dimethylamino)pyridine at the 2-position and 4-methoxypyridine at the 3-position, to afford bimetallic potassium pyridylzinc complexes each displaying a novel, but remarkably different, structure.

In this study, evidence of novel, important interactions between a hyperactive Tn5 transposon recognition end sequence and hyperactive Tn5 transposase (Tnp) are presented. A hyperactive Tn5 end sequence, the mosaic end (ME), was isolated previously. The ME and a wild-type end sequence, the outside end (OE), differ at only three positions, yet transposition on the ME is tenfold higher than on th...

Shield metal arc welding on the high strength low alloy steels in pipelines to transport natural gas from Iran is of great importance. In this article the effects of annealing heat treatment on properties of multi pass welding in different situations (6-4:30 , 4:30-3 , 3-1:30 , 1:30-12) with 36 in outside diameter is evaluated by chemical,  metallography, tensile, toughness and hardness. Tensil...

The RepA protein from bacteriophage P1 binds DNA to initiate replication. RepA covers one face of the DNA and the binding site has a completely conserved T that directly faces RepA from the minor groove at position +7. Although all four bases can be distinguished through contacts in the major groove of B-form DNA, contacts in the minor groove cannot easily distinguish between A and T bases. The...