Supramolecular ferric porphyrins and a cyclodextrin dimer as antidotes for cyanide poisoning.

OBJECTIVES: This study aimed to evaluate the antidotal effect of a newly developed supramolecular complex, ferric porphyrins and a cyclodextrin dimer (Fe(III)PIm3CD), that possess a higher binding constant and quicker binding rate to cyanide ions than those of hydroxocobalamin (OHCbl) in the presence of serum protein. METHODS: First, in vitro cytochrome activity and cell viability were evaluated in murine fibroblast cells cultured with various doses of Fe(III)PIm3CD and potassium cyanide (KCN). Next, BALB/c mice were pretreated with intravenous OHCbl (0.23 mmol/kg), Fe(III)PIm3CD (0.23 mmol/kg), or saline and then received KCN (lethal dose 100% (LD100): 0.23 mmol/kg) through a stomach tube. Finally, as a resuscitation model, KCN-induced apnea was treated with a bolus injection of an equimolar dose of antidotes followed by a slow infusion of the same reagent. RESULTS: Fe(III)PIm3CD showed dose-dependent antidotal effects in vitro. Pretreatment with Fe(III) PIm3CD prevented KCN-induced apnea significantly better than OHCbl. Resuscitation with Fe(III)PIm3CD resulted in an earlier resumption of respiration than that seen with OHCbl. However, 24-h survival was similar among the treatments (Fe(III)PIm3CD, nine of nine mice; OHCbl, eight of nine mice). CONCLUSION: Fe(III)PIm3CD exerted significant antidotal effects on cyanide toxicity in vitro and in vivo, with a potency equal in the mortality of cyanide-poisoned mice or superior in the respiratory status during an acute phase to those of OHCbl.

Development of a compact electron ion coincidence analyzer using a coaxially symmetric mirror electron energy analyzer and a miniature polar-angle-resolved time-of-flight ion mass spectrometer with four concentric anodes.

A compact electron ion coincidence (EICO) analyzer that uses a coaxially symmetric mirror electron energy analyzer and a miniature polar-angle-resolved time-of-flight ion mass spectrometer with four concentric anodes was developed for surface science and surface analysis. The apparatus is especially useful in the study of ion desorption stimulated by an Auger process because information on the mass, yield, desorption polar angle, and kinetic energy of ions can be obtained for the selected core-ionization-final-states or the selected Auger-final-states. The analyzer can be used also for analysis of the configuration of specific surface molecules because the desorption polar angles reflect the direction of surface bonds. The EICO analyzer was evaluated by measuring polar-angle-resolved-ion yield spectra and coincidence spectra of Auger-electron and polar-angle-resolved H(+) from condensed water.

Construction and evaluation of a miniature electron ion coincidence analyzer mounted on a conflat flange with an outer diameter of 114 mm.

We have developed a miniature electron ion coincidence (EICO) analyzer mounted on a conflat flange with an outer diameter of 114 mm. It consists of a cylindrical mirror analyzer (CMA), a time-of-flight ion mass spectrometer (TOF-MS), a commercially available linear motion feed through, and a tilt adjustment mechanism. Each sample surface was irradiated by synchrotron radiation, and the energies of emitted electrons were analyzed and detected by the CMA, while desorbed ions were collected by the TOF-MS in coincidence with the electrons. The performance of the EICO analyzer was tested by measuring the Auger-electron H+ photoion coincidence spectrum of condensed water at 4a1 <-- O 1s resonance.

Polarized near-edge x-ray-absorption fine structure spectroscopy of C60-functionalized 11-amino-1-undecane thiol self-assembled monolayer: molecular orientation and evidence for C60 aggregation.

Near-edge x-ray-absorption fine structure (NEXAFS) spectroscopy was adopted to probe the unoccupied electronic states of C60 anchored onto an organized assembly of 11-amino-1-undecane thiol on Au(111). The polarization dependence of the intensity of pi* resonance associated with C60 pi network revealed the self-assembled monolayer (SAM) system to be oriented with an average molecular tilt angle of 57 degrees with respect to the surface normal. Invoking the absence of solid-state band dispersion effects and in comparison to solid C60 and /or 1-ML C60/Au(111), the electronic structure of the resulting assembly was found dominated by spectral position shift and linewidth and intensity changes of the lowest unoccupied molecular orbital (LUMO), LUMO+1, and LUMO+2 orbitals. The latter implied hybridization between N Pz of -NH2 group of thiolate SAM and pi levels of C60, resulting in a nucleophilic addition with a change in the symmetry of C60 from Ih to C1 in the SAM. Occurrence of a new feature at 285.3 eV in the NEXAFS spectrum, assigned previously to pi* graphitic LUMO, signified the formation of aggregated clusters, (C60)n of C60 monomer. Low tunneling current scanning tunneling microscopy confirmed them to be spherical and stable aggregates with n approximately 5.

[Bond strength between nonprecious metal alloy and porcelain. (Part 2) Effects of the addition of Mn, Mo, Si, Sn, Ta and Ti on bond strength of 80 Ni-20 Cr alloy (author's transl)].

Alloys added 2, 4 and 6 wt% Mn, Mo, Si, Sn, Ta and Ti to 80 wt% Ni-20 wt% Cr alloyand no-added 80 wt% Ni-20 wt% Cr alloy were prepared and casted to obtain the test specimens 3 mm in diameter 25 mm in length. Ceramco porcelain (B.F. Vacuum Porcelain) was fused to each of these specimens, and the bond strength was measured by the pull-out method which applies shear stress to the metal/porcelain interface to investigate the effect of each addition element. The test results may be summarized as presented below. 1) The bond strength between the 80 Ni-20 Cr alloy and the porcelain was 182 +/- 14 kg/cm2. 2) Of the six kinds of addition elements, it was Mo, Sn, Ta and Ti that increased the bond strength. 3) The bond strength between the alloy added 6 wt% Ti to the 80 Ni-20 Cr alloy and the porcelain was 319 +/- 8 kg/cm2, which was increased by about 75% over the strength between the 80 Ni-20 Cr alloy and the porcelain.

[Bond strength between nonprecious metal alloy and porcelain. Part (1). Bond strength with press condensing method (author's transl)].

For the purpose of finding out the method which is able to evaluate nonprecious metal/porcelain bond strength easily, Ceramco procelain was fused to casted Wiron "S" (3 mm diameter), by means of 5 types of press condensing methods; the bond strength was measured by pull out method and these condensing methods were compared. Results are follows: (1) No significant difference was observed between conventional condensing method and press condensing method (condensing pressure; 472-1 415 kg/cm2), and the bond strength of Ceramco Paint-O-Pake porcelain to Wiron "S" was about 245-369 kg/cm2. (2) Bond strength was decreased with the decrease of the fused length of procelain. (3) Bond strength was increased approximately three times, when specimens were mounted by dental stone.