The performance of a new pulsed arc cluster ion source (PACIS) is demonstrated for pure metal cluster ions and anions as well as mixed metal-rare-gas clusters. Pure metal clusters like W$ exhibit intensity distributions similar to those from laser vaporization sources. The ion current of the PACIS is comparable to that of a laser vaporization source. For metal-doped argon cluster ions, a single...

Mn(TPP)Cl catalyzes cooxidation of olefin in the singlet oxygenation of sulfid. Mn(TPP)Cl is able to transfer an oxygen atom from a peroxidic intermediate generated in singlet oxygenation of sulfide to a metal ion affording metal 0x0 species which is responsible for epoxidation. This system leads to allcenes epoxidation such as styrene and cyclooctene. Epoxidation of cyclohexene produces cy...

A series of MAl2O4 (M=Ni, Zn, and Cu) aluminates were prepared by using impregnation method; the metal content of the products was ranged between 5wt% to 25wt%. The samples were characterized by x-ray diffraction (XRD), Brunauer Emmett Teller (BET) surface area, NH3 temperature-programmed desorption (NH3-TPD), and inductively coupled argon plasma (ICP). The specific surface areas of zinc, ni...

The nuclease domain of ColE7 (N-ColE7) contains an H-N-H motif that folds in a beta beta alpha-metal topology. Here we report the crystal structures of a Zn2+-bound N-ColE7 (H545E mutant) in complex with a 12-bp duplex DNA and a Ni2+-bound N-ColE7 in complex with the inhibitor Im7 at a resolution of 2.5 A and 2.0 A, respectively. Metal-dependent cleavage assays showed that N-ColE7 cleaves doubl...

BACKGROUND Adverse Reaction to Metal Debris (ARMD) is still a major reason for revision surgeries in patients with metal-on-metal (MoM) hip replacements. ARMD consists of a wide range of alterations in periprosthetic tissues, most important of which are metallosis, inflammation, pseudotumors and necrosis. Studies investigating histopathological findings and their association to implant wear or ...

One of the most important chemical concepts is defining how one molecule recognizes and controls the properties of another molecule or ion. Nowhere is this issue more significant than in the field of biomolecular recognition. Metalloproteins efficiently control the geometry and coordination number of metal ions as well as the types of ligands bound to them. Incorporation of metals in the correc...

The new signaling probes 2-6, rhodamine-B derivatives of various receptors which contain different donor atoms for effective metal ion coordination, were synthesized and their absorption as well as fluorescence spectral responses were evaluated in the presence of various metal ions. All these probes along with the reference probe 1 have exhibited optimal metal ion-induced absorption and fluores...

The ability to chemically synthesize biomolecules has opened up the opportunity to observe changes in structure and activity that occur upon single atom substitution. In favorable cases this can provide information about the roles of individual atoms. The substitution of 6-thioguanine (6SG) for guanine is a potentially very useful single atom substitution as 6SG has optical, photocrosslinking, ...

One of the most important chemical concepts is defining how one molecule recognizes and controls the properties of another molecule or ion. Nowhere is this issue more significant than in the field of biomolecular recognition. Metalloproteins efficiently control the geometry and coordination number of metal ions as well as the types of ligands bound to them. Incorporation of metals in the correc...

Metal ions are essential cofactors for various ribozymes. Here we dissect the roles of metal ions in an aminoacyl-tRNA synthetase-like ribozyme (ARS ribozyme), which was evolved in vitro. This ribozyme can charge phenylalanine on tRNA in cis, where it is covalently attached to the 5'-end of tRNA (i.e. a form of precursor tRNA), as well as in trans, where it can act as a catalyst. The presence o...