The structure of solid zirconium tetrachloride is known from X-ray studies[l] to consist of extended chains of distorted octahedra with two bridging chlorine atoms between adjacent zirconium atoms. Although the unit cell possesses a center of symmetry, the two pairs of bridging chlorine atoms attached to a given zirconium atom are not trans to each other. The factor group symmetry thus is C2h w...

We already reported that an intramolecular benzylation of the imino moiety of bidentate iminopyrrolyl ligands afforded an amido-pyrrolyl complexes 1 and they exhibited better catalytic activity for ethylene polymerization compared to the corresponding bis(iminopyrrolyl) dichloro complexes of zirconium. In this contribution, we prepared amido-pyrrolyl complexes of zirconium (3a-d) and hafnium (4...

IMPORTANCE Hyperkalemia is a common electrolyte abnormality that may be difficult to manage because of a lack of effective therapies. Sodium zirconium cyclosilicate is a nonabsorbed cation exchanger that selectively binds potassium in the intestine. OBJECTIVE To evaluate the efficacy and safety of zirconium cyclosilicate for 28 days in patients with hyperkalemia. DESIGN, SETTING, AND PARTIC...

OBJECTIVE The purpose of this study was to determine the fracture strength of zirconium implant abutments and the torque required to unfasten the retaining screw before and after applying cyclic loading to the implant-abutment assembly. The dynamic behavior and stress distribution pattern of zirconium abutments were also evaluated. METHODS AND MATERIALS Static and cyclic loading of 7 XiVE imp...

The control of ice nucleation and growth is critical in many natural and engineering situations. However, very few compounds are able to interact directly with the surface of ice crystals. Ice-structuring proteins, found in certain fish, plants, and insects, bind to the surface of ice, thereby controlling their growth. We recently revealed the ice-structuring properties of zirconium acetate, wh...

In this study, 2, 2', 3, 4-tetrahydroxy-3'-sulpho-5'-carboxyazobenzene (tetrahydroxyazon SC) has been synthesized for the first time and used for direct spectrophotometric determination of zirconium(IV). Tetrahydroxyazon SC in a 5.0 M acidic medium (up to pH 6) with zirconium(IV) gave a red complex (Zr-tetrahydroxyazon SC), which has maximum absorption at 495 nm (molar absorptivity, 4.9x104 l m...

background : in anterior endodontically treated teeth a better esthetic can be achieved by using all-ceramic post -core restorations instead of metal post systems. maximum retention and fracture resistance of the post are the criteria upon which selection of a post system is based. the aim of this study was to evaluate the fracture resistance and retention of two all-ceramic post and core syste...

Ternary amorphous W–xCr–yZr alloys containing 9−38 at % tungsten, 15−42 at % chromium and 39−73 at % zirconium were successfully prepared by direct current (DC) magnetron sputtering technique. The corrosion rates of all the examined sputter−deposited W–xCr–yZr alloys were in the range of 1 × 10−3 mm/y or lower which are nearly one order of magnitude lower than those of the sputter−deposited tun...

We investigated the wear characteristics and clinical performance of four different total hip joint articulations in 114 patients. Wear and migration was measured by roentgenstereophotogrammetric analysis at five years or at the last follow-up. The mean annual wear was 0.11 mm for a stainless steel/Enduron articulation, 0.34 mm for stainless steel/Hylamer cup, 0.17 mm for zirconium oxide cerami...

Study of the implant-tissue interface is one of the fundamental issues in implantology, both odontologic and orthopedic. The characteristics of this interface will influence the success or failure of an implant. The aim of the present study was to evaluate histomorphometrically the capacity of different metals to osseointegrate employing laminar implants of zirconium, titanium, aluminum, and zi...