Hierarchical micro-/nano-structures made easy. By using extremely rough, chemically etched microstructured aluminium foils, anodization in phosphoric acid under very harsh conditions, e.g., 10 wt% phosphoric acid and room temperature, can be repeatedly accomplished without suffering from breakdown. As a result, an alumina membrane with a three-dimensionally distributed nanopore structure is for...

Asymmetric allylation of (hetero)aromatic aldehydes by a zinc(II)-allylbutyrolactone species catalyzed by a chiral BINOL-type phosphoric acid gave β-substituted α-methylenebutyrolactones in 68 to >99% ee and 52-91% isolated yield. DFT studies on the intermediate Zn2+-complex - crucial for chiral induction - suggest a six-membered ring intermediate, which allows the phosphoric acid moiety to act...

This study was conducted to examine the shear bond strengths of orthodontic brackets to ground enamel with two self-etching adhesives (Beauty Ortho Bond and Transbond XT) and two phosphoric acid-etching adhesives (Kurasper F and Orthomite Superbond). After the bonded specimens were stored in water at 37 degreees C for 24 hours, they were subjected to thermal cycling (TC) at 0 and 5000 cycles. T...

The publications on Kjeldahl’s method for determining nitrogen that have appeared since Kjeldahl’s (1) original paper in 1883 perhaps outnumber those on any other analytical method in the same period of time.1 The diversity of papers is attributable to the immense usefulness of the method, to its need for modifications for applications to various types of organic and inorganic compounds, and to...

UNLABELLED The self-etch approach provides dentists with a generation of user-friendly and less technique-sensitive adhesives. Nevertheless, some concern has been raised regarding their bonding effectiveness to enamel, in particular when so-called 'mild' self-etch adhesives are employed. OBJECTIVES The purpose of this study was to test the hypothesis that the two-step self-etch adhesive Clear...

The Brazilian phosphate fertilizer is obtained by wet reaction of igneous phosphate rock with concentrated sulphuric acid, giving as final product, phosphoric acid and dehydrated calcium sulphate (phosphogypsum) as by-products. Phosphoric acid is the starting material for triple superphosphate (TSP), single superphosphate (SSP), monoammonium phosphate (MAP) and diammonium phosphate (DAP). The p...

Surface treatment of dentin before the bleaching procedure may affect its permeability and influence the bond strength of restorative materials. This study evaluated the influence of surface treatment before the bleaching on shear bond strength (SBT) of restorative materials to intracoronal dentin. Dentin slabs were subjected to surface treatment: no bleaching (control - CON), no surface treatm...

PURPOSE Numerous methods were used to etch the fiber posts to improve its bonding to root canal dentin. Our aim was to evaluate the efficacy of 37% phosphoric acid in etching fiber posts in comparison with 24% hydrogen peroxide. MATERIALS AND METHODS Ninety human maxillary central incisors were taken and post space preparation was done. Ninety fiber posts were taken and divided into three gro...

This study evaluated the shear bond strength of stainless steel brackets bonded to enamel with a new fluoride-releasing orthodontic adhesive system. A total of 140 extracted human bicuspids were randomly divided into four groups. Group I (Transbond XT) was a control group in which enamel was etched with phosphoric acid. For the remaining groups, enamel was conditioned with a self-etching primer...

The conical nanostructure improves the applications of alumina membranes and provides three dimensional nanometer scale systems to study the chemical and physical properties. In this study, the nano cone structure is produced in porous anodic alumina (PAA) by two-step anodizing. This conical nanostructure will improve the application of PAA membranes. This approach is novel generation of t...